Objective & Background
Grid-integration of fluctuating solar power requires forecast information on the expected power production as a basis for management and operation strategies. With increasing importance of photovoltaic (PV) power for the world-wide energy production, PV power prediction services are already an essential part of grid control and energy trading.
In this presentation we present an integrated combinational PV power forecast based on machine learning algorithms. The aim is to cover a wide range of forecast horizons from short term (i.e. several hours) to several days ahead. Also, the system shall be applicable both for single PV systems and grid controlling zones. The combinational forecasting system shall be used to optimize the grid and market integration of Renewable Energies.
The basis for the combinational forecast are three independent information:
NWP models are widely used for day-ahead forecasting. However, due to the high amount of computing time there are only few updates per day. So NWP shows limited accuracy for the next hours.
Short term (or intra-day) forecasts in this study are based on cloud observations from satellite. By comparing consecutive satellite images, and by means of pattern recognition, the speed and direction of cloud motion is derived. By integrating thermal (infrared) satellite observations, forecasts are also available in the morning hours where no information is available from images taken in the visual spectral range.
(Online) measurements of PV power production from monitoring systems are important information for the combinational forecast. They are used for the short-term adaption and lead to a significant reduction of the systematical error.
Finally, machine learning algorithms are applied to combine all three information depending on the weather situation and the forecast horizon.
Evaluations will be performed both for large portfolios (here: electricity grid controlling zone in Germany) and for single sites (here: reference PV systems in India). The evaluation covers different forecast horizons from few hours to day ahead. All results will be compared to real PV power production measurements.
One interesting result will be the forecasting accuracy for single sites as already now large PV plants are obligated to provide forecasts in many markets for grid security reasons.
Conclusion and Outlook
By using machine learning algorithms the accuracy of a combinational PV power forecast is expected to be better than each of the contributing forecasts for all forecast horizons. Further investigation is needed to fill the gap of information between the actual production (‘forecast horizon’ 0 minutes) and the satellite forecast (highest accuracy 1 to 2 hours ahead). So as an outlook the use of sky imaging cameras is addressed.
With the growing number of distributed power producers of renewable energy, the demand for a new way of managing these distributed assets is increasing. A Virtual Power Plant can help controlling and monitoring such assets for providing a stable grid. This abstract provides a VPP case study by outlining the possibilities and complexity of monitoring and controlling a Power-to-Gas (PtG) plant through a Virtual Power Plant (VPP). This Power-to-Gas project is run by Greenpeace Energy together with the German city of Haßfurt.
The power-to-gas plant itself has a capacity of 1.25 MW. The plant operates according to the demand and renewable energy feed-in into the local electricity grid of the municipal utility “Stadtwerk Haßfurt GmbH”. Generally speaking, a PtG plant transforms excess electricity (in this case mostly wind energy) into hydrogen. Within certain constraints, this hydrogen can be fed into the natural gas grid. The challenge with this task is to know, when there is too much renewable energy fed into the grid, so it is more feasible to convert electricity into gas, prevent curtailment and optimize grid use. Next Kraftwerke as a VPP operator forecasts both the feed-in from renewable energies in the region and the total electricity consumption in the distribution grid. Another restriction which the virtual power plant takes into account, is the hydrogen concentration of the local natural gas network, in which the hydrogen produced in the electrolyzer of the power-to-gas plant is fed-in. Based on this data, the control system of Next Kraftwerke’s VPP calculates the times, when the electrolyzer of the PtG will be used and then automatically switches it on via a remote control unit installed on site called Next Box. The result: the power-to-gas system only starts up when renewable energies are available in abundance and thus relieves the regional distribution grid. The excess gas produced will be fed into the local gas network.
Aside from making use of the excess wind energy, also the grid operators can benefit from the fast-paced development of power-to-gas technology: the electrolyzer is also ideally suited for providing grid frequency control for the German grid operators. The plant follows the steering signal from the virtual power plant within milliseconds and is able to provide a flexible capacity of 1.25 MW within 20 seconds. It provides all three German grid frequency control products: R1, R2 and R3. The attached illustration shows a detailed overview of the project and the dedicated roles of the Virtual Power Plant.
UL's wind certification services support grid integration for decentralized power generating units and power plants according different international Grid Codes like the Central Electricity Authority (CEA) Technical Standards for connectivity to the Grid and the German Grid Codes (VDE-AR). Basis of the certification services is the DIN/ISO 17065 accreditation.
The aim of this paper is to exploit the long experience of UL (DEWI-OCC) in the field of grid connection certification according the German Grid Codes and Certification in Germany in order to propose a relevant Certification Scheme for India considering the latest developments in the Indian Regulations. The proposed scheme will also consider the latest progress within the working committees of the FGW and IECRE, where UL is a member which issues the Technical Guidelines for Certification, Testing and Modelling/Simulation and ensure the high quality of the processes.
The Certification process for Integration of wind turbines and wind farms into the Grid of the German Grid Operator contains 3 Parts.
1. Unit Certification
a. Testing/evaluation of the electrical characteristics like PQ and FRT
b. Evaluation of the Design, Control and Functions of the wind turbine
c. Validation of Simulation Model regarding the FRT test results
d. Issuing unit certificate for a specific wind turbine type
2. System Certificate
a. Evaluation of the Design, Control, Protection, Components and Functions
b. Modelling the wind farm and Simulation of the FRT at the grid connection point
c. Issuing of power generating system certificate before commissioning of the first wind turbine
3. Conformity Declaration
a. Evaluation of the commissioning and as-built documentation, protection test and parameterization
b. Inspection of erected wind turbines in case of type, parameter, protection and function
c. Inspection of Grid Connection Point components in case of protection, communication, parameter and control system
d. Issuing of conformity declaration
Based on the experience on this certification process, UL proposes a procedure to verify compliance to CEA and MNRE requirements. The process include specific suggestions and recommendations e.g. on evaluation and check of test results of different wind turbines which are technically comparable. How to transfer the test results from one wind turbine to another. UL proposed procedure will be based on the transfer rules of the IEC61400series and the FGW Technical Guideline 8. These rules ensure a adequate technical transfer and prevent inappropriate transfer of test results. The evaluation and issuing of conformity Statements acc. the CEA Technical Standard will be discussed in detail and proposals for the improvement and optimization of this procedure will be presented. With our experience we are able to issue approrpiate Conformity statements for several key OEM in the market. UL can offer testing and certification acc. the Technical Standard of CEA and IECRE.
In the present scenario of huge demand for energy economy necessitates development of various energy resources either,conventional and non-conventional.Despite rapid depletion of fossil fuels across the world, billions of people are yet devoid of the comfort offered by electricity.If the consumption of fossil fuel continues at the current rate, the future generation is bound to suffer from the acute shortage.The associated global warming and ozone layer depletion caused due to intensive application of fossil fuels forces us to look for solar based systems.One such system is an Organic Rankine Cycle (ORC) plant which is modular and scalable. It can be easily transported, assembled and commissioned rapidly at site, may it be in small industrial units or “micro-grids” for remote and isolated areas. The heat-energy converter of the ORC plant is a hermetically sealed unit with a few moving parts. This technology now turns out to be proven and available to all. The plant requires no operator, the maintenance cost is negligible over long periods, and the unit can be operated and monitored remotely. The design, technologies and materials proposed to be used are largely indigenous and it acquires a significant improvement over the traditional units used earlier for large plants, thus it provides acceptable performance at low capital cost. The solar energy available for almost 295 days a year in India is utilized by an array of sun-tracking parabolic-trough collectors. The functionality and performance of such newly developed low-temperature ORC unit comprising of helical coil solar cavity receiver based parabolic trough concentrator (PTC) was investigated at CERD, Mechanical Engineering, IIT(BHU), Varanasi. The PTC comprised of blackened helical coil made up of two concentric borosilicate glass cylinder with vacuum in annulus was kept at focal line that maximized the conversion of energy received from sun into useful heat and eventually electricity.
As power systems around the world transform, power system flexibility has become a global priority. A range of operational, policy and investment-based interventions are available to render modern systems more flexible, thereby facilitating cleaner, and more reliable, more resilient, and more affordable energy. This report identifies challenges and opportunities to unlock system flexibility and accelerate power system transformation (PST) efforts. It provides an overview of the policy, regulatory and market instruments which can be implemented in different power sector contexts to mitigate these challenges. Importantly, all power system assets, including variable renewable energy, can provide flexibility services, if enabled by proper policy, market and regulatory frameworks. These assets include power plants, electricity networks, energy storage and distributed energy resources. A wealth of known strategies, approaches and instruments can be readily applied and adapted to power systems. These include modifications to: energy strategies; legal frameworks; policies and programmes; regulatory frameworks; market rules; system operation protocols; and connection codes. Moving forward, updating system flexibility policies to match the pace of technological development can help to accelerate global PST, while ensuring that all classes of power system assets are able to receive fair remuneration for the flexibility services they are capable of providing.
All power system assets can provide flexibility services if enabled by proper policy, market and regulatory frameworks. Even VRE resources are emerging as a flexibility resource. Several countries (e.g. Australia, Ireland, Spain and the United States) have introduced market reforms and regulations that activate VRE flexibility. In the United States, innovative flexibility retrofit investments have been demonstrated in existing conventional power plants, such as hybridisation with BESS. Moving forward, efforts to modify connection codes and market rules will be key for all assets – including power plants, electricity networks, DER and energy storage – to receive fair remuneration for their flexibility services.
Electricity networks remain a critical enabler of system flexibility. Various policy and regulatory instruments can de-risk new network investments in support of system flexibility, and promote more “system-friendly” deployment of VRE. In the United Kingdom, a “cap-and floor” regulatory regime mitigates investment risk in merchant interconnection projects by protecting investor in years with low market revenue in exchange for capping revenues in high revenue years.
Battery energy storage systems are becoming a cost-competitive flexibility provider. Regulatory innovations can help to unlock the multiple value streams of energy storage. Australia, the United Kingdom, the United States and the European Union’s Electricity Directives offer useful examples of regulatory innovations.
Anti-islanding protection is very important for modern inverters connected to utility. India is a fast growing economy with raising energy consumption through renewables having a target of 175 GW by 2020. This paper describes the anti-islanding protection function in a 20 kW solar-wind hybrid inverter with battery backup option considering only the solar input side connected at input and utility connected at output side. As per the Indian standard 16169 which was released in 2014, any power conditioning unit connected to utility must disconnect from utility within 2s after it goes off-line. The three different voltage levels and total of 31 conditions were simulated for various real and reactive power maintaining quality factor 1 at utility side through a 200 kW RLC load and the disconnection time of inverter were obtained through a high definition oscilloscope. For the inverter tested for anti-islanding protection function, it was found that in all scenarios the inverters disconnection time was well within two seconds as per the limit imposed by IS 16169:2014.
India has set a target of achieving 175GW generation through solar, wind and other renewable resources to be achieved by end of year 2022. In the near future when renewal penetration to the network will be sufficiently large, it will impose several challenges for grid operator. The issue of maintaining voltage profile during dynamic and transient grid conditions subsequent to renewable mix generation needs to be looked into, on top priority. The flexible generation due to unpredictable wind pattern and solar generation which sometimes varying in nature due to cloud movement, will impose a challenge to ensure the power quality and efficient grid operation. The additional large scale VAR control requirement due to solar and wind addition needs to be met by installing new VAR compensation equipments.This paper suggests use of spare generators stored at different projects as synchronous condenser to augment MVAR requirement of different regional grids. The investment to install synchronous condenser is much lower as compared to other FACTs devices, besides offering better performance under dynamic conditions emerging from renewable generation variations. The machine will also meet high short circuit current requirement and high inertia due to rotating heavy mass to take care of transient active power support.
Several large rating turbo-generators (500MW, 660MW and 800MW) are available and stored at different project sites in India. It may be noted that stator replacement of large unit has been very rare in past. Also the rewinding of generator can be done almost in same time span as required in case of replacement of large turbo-generator.
Condition of Generator insulation system- It has been seen that the condition of machine insulation system deteriorates, if it is not in operation and adequate measured for protection not taken during long storage. In absence of proper storage guidelines, many times these machines expose to poor environmental conditions causing insulation deterioration.
It is proposed to use these spare generators at location close to their site in respective regions as synchronous condenser to meet the VAR requirement of system during dynamic and transient conditions.This scheme will make the machine available in healthy condition, if required to meet any eventuality in future.
Major benefit of using spare 588MVA, 776MVA and 940MVA generators,will meet frequent MVAR support requirement. Also improving the grid stability and power quality. The synchronous condenser also has several advantages, especially high Short Circuit and inertia to handle transients and dynamic disturbances. The proposed layout plans in paper.
Energy is one of the most important building blocks in human development, and as such, acts as a key factor in determining the economic development of all the countries. In an effort to meet the energy demands, non-renewable resources are significantly depleted by human use and use of renewable resources of energy is rapidly increasing worldwide as they can sustain indefinite human exploitation.
The Solar power, one of the potential energy sources, is a fast developing industry in India but only through exploiting solar energy, India cannot become energy surplus due to the limitations of Solar Power in terms of availability, technological efficiency and economical feasibility.
Therefore it is need of the hour to explore promising sectors of renewable energy and among the promising sectors, Hydro power sector is the most suitable.
To meet the country’s target of producing renewable energy of 175 GW by 2022, the hydro power sector can contribute majorly as India have the total potential hydropower is 1,48,704 MW, of which 84% potential hydropower is concentrated in the Himalayan Regions states. But utilization of this Hydro power potential does not possible without making Dam or Reservoir or Head based hydro power plant installation.
Building large hydro dams is very costlier as the large hydropower projects include Sardar Sarovar project and Maheshwar Project in Narmada valley in Madhya Pradesh, etc. are witnessing displacement of thousands of people from their ancestral place, destroying their livelihoods and violating human rights in the name of development leaving them with no alternatives. After so many years of the struggle, thousands of displaced people from above projects still waiting for justice in these valleys. Apart from anthropogenic loss, these projects permanently destroyed the local environment and contributed in global warming by engulfing major chunk of forest.
The only way forward in order to save rivers and reduce the current rate of ecological degradation is to switch towards alternate hydro energy generation technologies in which without making any civil structure, electricity can be generated through hydro turbines. That is the main reason why we have chosen Hydrokinetic is the field of energy generation as VARUN-III, Product of MACLEC, generates electricity directly from water velocity, without making dam or any civil structure.
VARUN-III is hybrid of Solar PV System and Hydrokinetic Turbine installed in a single floating platform which allow it to harness electricity from running water as well as from sunlight. Installation of Solar on the floating structure of hydrokinetic Turbine VARUN-III save land cost, reduce installation and power transmission cost apart from it easy availability of water facilitate O&M of Solar.
First pilot of Solar Hydrokinetic Hybrid have been installed successfully at Upper Ganga Canal in collaboration with Government and results are encouraging
After five years from the introduction and implementation of grid connectivity requirements for wind turbines and generating stations using inverters, the Central Electricity Authority of India (CEA) has recently come up with an amended Regulation, including modifications and new connection rules, such as:
The experience from testing and certification according to the previous requirements, has shown that the existence of a concrete and unambiguous testing and certification procedure for the verification of grid compliance is important for all involved parties (public authorities, manufacturers, testing and certification bodies etc.) to work more efficiently and speed-up the installations of distributed power generating stations in India, towards the ambitious goal for renewable energy penetration set by the Government of India for 2022.
Following the latest CEA Regulation, UL developed an updated procedure for the Testing and Certification of power generating stations to conform to the new requirements. The new procedure takes into account not only the new CEA Regulation but also latest developments in the relevant international standards such as the new IEC 61400-21-1 standard for the testing WTs and the new revision of the German Testing guideline FGW-TG3. Further information from other standards under development is considered, such as the new EN 50549-10 for compliance testing of power generating units to the European network code, as well as the IEC 61400-21-2 which will cover the testing at the point of connection of wind power plants.
The presented work consists of the following parts:
The presented procedure aims at facilitating the work for grid compliance verification of the Public Authorities of India by aligning procedures among the involved Testing Institutes and Certification Bodies, whereas it will help the Manufacturers in the design and manufacturing phase of their Products.
This paper describes the results of a GIZ funded project, where the possibilities to control active power and to provide ancillary services with renewable energies in South India were investigated. The project, which was conducted in the first half of 2019, was split into two work packages. First, a survey was conducted to find out the capabilities of wind and PV plants in South India to control their active power and to provide ancillary services. This included also the available communication infrastructure and options for retrofitting.
In the second work package, the regulatory framework, grid code and market design was analyzed. In the next step suggestion for improvement were drafted to implement active power control and provision of ancillary services by wind and solar power plants. To elaborate these recommendations international best practices from different countries have been analyzed.
The state of the art in the grid compliance testing of wind turbines and solar inverters (PGUs) is to perform the tests in the field and only some components, such as the grid protection devices, may be tested at laboratory facilities. Field testing provides the advantage of examining the behavior of the complete system at actual environmental and grid conditions. On the other hand, test bench testing may give the possibility of performing further tests for the investigation of some electrical parameters of the PGUs in a more controlled and detailed manner, such as the reactive power dependency on voltage changes or the set-point control, but for tests like fault ride through capability and power quality, there are still many open technical issues to be addressed and discussed in order to establish a standardized and universally accepted procedure.
Main concerns which have to be investigated are the following:
- Which electrical characteristic parameters can be reliably tested at a test bench and which are the restrictions?
- Which tests are imperative to be performed in the field?
- How does the test bench characteristics influence the performance of the tested PGUs?
- How can we draw conclusions for the performance of the complete unit based on the subsystem or component testing?
Driven by these concerns, IEC has recently launched a dedicated Working Group aiming at the thorough technical investigation of the topic in order to define the relevant requirements to be included in a separate international standard for the measurement and assessment of wind turbine components and subsystems (future IEC 61400-21-4).
In the present paper, an investigation of the topic of subsystem testing of Wind and Solar stations is performed and specific proposals are formulated.
The work will consist mainly of the following:
• Description of the international experience and review of the status in the standardization of test bench testing worldwide
• Classification of test benches in terms of complexity (constant or varying torque, rotor modelling, inverter only without rotating machine etc.) and proposals for options that can be really applied from practical perspective.
• Proposal for the range of validity of the tests at a test bench
• Proposal for the field and test bench testing for the main electrical characteristics.
The contribution of the presented work will be to provide a necessary technical background for the advantages and disadvantages of wind turbine and solar inverter testing at test benches, to be considered for the grid compliance evaluation.
Mostly we use PV modules are based on poly or mono-crystalline technology. The I-V Characteristic of Solar Module Indicates Open Circuit Voltage as Voc and Short Circuit Current Isc. The modules are arranged in series to achieve the required dc bus voltage and in parallel for increasing current. This combination of series and parallel modules forms PV array. At any time, there exists a unique operating point at which the power is at peak i.e. max. Power Point (MPP). MPP fluctuates continuously as irradiance and temperature varies. So MPP tracker (MPPT) is needed to ensure the maximum power is always extracted from PV array. Electrical Power Generation in Solar Module is totally dependent on Solar Irradiance. Due to Non-Linear output characteristic Fault Detection is quite difficult. Partial Shading condition will result into low power. Line to Line fault at low power is difficult to detect. OCPD’s are not capable to detect faults in every condition. GFPD’s Improper Operation. Line to ground faults at higher irradiance. Faults on DC sides and High DC arc. Renewable energy is expected to play an increasingly prominent role in Indian power sector in the coming decades and giving its various benefits. The main intention for this study is to emphasizing on Renewable Energy and to improve the performance of Solar Power Plant by providing almost better MPP Tracker. There were several papers are available for the field of solar and deferent methodology is implemented to improve the same. It is quite difficult to identify the fault location in Solar PV system and especially at DC side for PV arrays. Main functions of charge controllers are low voltage disconnection (LVD) to protect the battery from deep discharge and high voltage disconnection (HVD) to protect the battery from overcharging. To improve the performance of PV output MPPT algorithm can be applied by matching the PV array impedance and load impedance. In P&O an initial point is chosen and perturb (or disturb) until the value of the variable is increasing. When the value decreases stop perturbing. Move in the reverse direction to obtain the maximum value. The Incremental Conductance (IC) method locates MPP by differentiating the PV power with respect to voltage. MPP is located when the differentiation result is zero. A boost converter can be applied on both the PV and grid for regulating the output voltage.
The main objectives of this paper is to Improve the Efficiency and Performance of Solar PV Grid Tied System with IOT based Tools/ Machine Learning. Raspberry Pi and Arduino can be used for the same and Performance can be improved along with the same monitoring of each array is also possible. Fault finding and repairing can become easy task for Plant Operator. Shadow effects can be optimized using the same.
Transport is the largest consuming sector representing 40 per cent of total energy in the world. The recent development of electric and hybrid vehicles is potentially providing effective solutions to the reduction of the use in fossil fuel. As per forecast by International Energy Agency (IEA) in its Global Outlook 2018 report, electric car stock will be ~ 70 million by 2025. World Bank announced that it will stop financing upstream oil and gas projects after 2019 to raise funds to finance a shift towards clean energy. In this paper the research challenge is to optimize a novel framework for managing electric vehicle telemetry data through a process of AI based Algorithm to translate this data into useful engineering information for new, model-based, control system solutions for the vehicle‟s performance. Current and voltage are the most commonly used detection parameters for EVs. Apart from these, temperature, vibration, power, noises, and torque are also utilized on the basis of different detecting techniques. Overheating of electrical machines leads to rapid failure. Hence, the main limitation on electrical generators and drive is a temperature limit, which is generally enforced with an electrical fuse (current limit). The smart sensors once integrated into system give real time information allowing an unparalleled understanding. Furthermore, they may be used to investigate fast charging protocols and ageing. For any specific faults in Electric Vehicle like over charge / overheating, short circuit / open circuit of cell etc in Energy storage fault and abnormal connection of stator winding, O.C. or S.C. of stator winding, bearing failure, S.C. of rotor winding etc in Electric Motor fault. We can consider n no. of case and optimize the value of that specific fault by analyzing data of fault. By doing feasibility study and design optimization of all faults in Electric Vehicle for specific condition we can build prototype for mathematical model of EV and validate simulation results with experimental data through Lab demonstration model.
Integration of renewable energy sources introduce uncertainties and strains to the power system operations, which is closer to stability limits. The integration of renewable generation with conventional power grid poses challenges to power system dynamics due to its variable nature and different type of renewable generation have different behavior pattern. This requires the real time monitoring of electric grid, which can be achieve through Wide Area Monitoring Systems (WAMS).
Synchronized phasor measurements is already recognize as one of the promising technologies for developing Smart Grid applications. In recent year’s power, utilities all over the world focused their attention to deployment of Phasor Measurement Units (PMUs), which measure power system parameters in real-time. GETCO had taken a pioneer step for installation of 118 PMUs at 25 Location including 4 RE rich location in Gujarat grid. This paper covered how Synchrophasor Technology will help in addressing integration of renewable with synchronous grid. GETCO experience of implemented synchrophasor technology in grid, & potential application of PMUs for Power systems operation under high wind penetration & other RE sources and impact of RE on power quality issues by using PMU data is presented.
The Power Installed Capacity of Gujarat State is 28.1 GW includes 8.0 GW installation of RE & 0.78 GW Hydro. The wind installation is 5.80 GW and Solar is 2.20 GW. The uses of hydro is as per irrigation and drinking water requirement. The hydro generation remains available only in peaking hours. The reversible pump mode operation in hydro station is yet to be established. There are adequate gas based installation in the State, but, it is not on disposal for meeting variability of wind generation due to high variable cost.
The maximum demand of the State remains 15 to 18 GW. The 1.5 GW wind & 2.5 GW demand variation in a day are quite common. The State is committed to tap generation from all renewables without curtailment, to supply uninterrupted, reliable power to its citizens. SLDC Gujarat has tapped ever highest 4.75 GW wind, 1.4 GW solar, 18.4 GW demand without any interruption and curtailment.
In era of tight DSM regulation, The State grid operation is passing through shortage of balancing resources, absence of ancillary services and many challenges.
The State has always strives for accurate renewable energy forecasting, demand forecasting, maintaining network availability, system parameters for ensuring reliable and economic grid operation by adopting new technologies and software applications.
The system operation scenarios with high RE capacity mainly divides:
High wind - less solar – less demand scenario
Less wind – high solar – high demand scenario
High wind variation – high solar – less demand variation
High wind variation – high solar – high demand variation
High wind – high solar – high demand
There are different kind of challenges in all above scenarios.
For smooth RE integration, the basic requirement is to have accurate wind & load forecasting and to have accurate weather forecasting data, real time generation data of all RE resources.
Most of RE pooling stations are located on coastal lines. The humid and saline atmosphere affects significantly on performance of Transmission Network. The pooling station owner are not coming forward for establishing Reactors, Capacitor banks, SPS, wind MoD etc. Sometimes, they are reluctant to curtail RE generation when there are major constraint.
The GoI has given target to the Gujarat State to enhance Solar capacity to 8.0 GW and wind capacity to 8.8 GW by 2022.
As way forward, there is an emerging need to introduce regulatory framework for getting accurate RE forecasting from pooling station, installing reactors and capacitor banks at pooling stations, commencing HVRT / LVRT features in all type of WTGs, introducing Merit order dispatch, Providing SPS for curtailment of wind energy. if need arise, Energy storage devices and to operationalize pump storage devices in the system by way of introducing ancillary services. It shall be necessary that pooling station owners should adopt and vigorously follow the recognized practices for conditional monitoring & maintenance.
The possible challenges of high Renewable Energy (RE) integration arise when the online generators are short of ramping capability and offline generators need time to come online to meet the ramping requirements. To improve flexibility and security of power system for RE accommodation, additional reserve margin may be required. This paper analyzes the net load variations and developing ancillary service requirements to support renewable expansion, the determination of appropriate constraints that reflect the additional variability and short-term uncertainty introduced by RE generation through statistical analysis.
By 2022, the MNRE targets total 160 GW variable RE (vRE i.e. wind & solar) installation in India with highest RE targets for the state of Tamil Nadu, 8,884 MW Solar and 11,900 MW Wind. To put this in context, the projected Peak demand in 2022 for Tamil Nadu is around 21.5 GW while peak demand for the Southern Region is around 66.7 GW (as per 19th Electric Power Survey of India), thereby indicating that in absolute terms the total RE installed capacity in Tamil Nadu is ~94.14% of the state’s peak demand and 31.15% of the Region peak demand. Analyzing such large RE installation in a state is crucial for the dispatchers to understand and quantify the impact on the thermal power plant performance and maintaining the system stability.
High-resolution load and vRE production data for a chronological period are the primary inputs to this analysis. For each 15-minute interval, the change in net load is calculated to determine the variability in vRE generation within the hour. Then mathematical and statistical techniques was applied to characterize and quantify this variability in the case where reserve requirements are determined prior to the operating hour. These statistical characteristics are required to develop reserve requirements. The process starts with the determination of 15-minute variability in vRE generation (Delta), followed by utilizing this variability to determine the standard deviation limits within which the vRE generation is likely to deviate from the forecasted values (Sigma Delta). Based on experiences gained from previous instances, it was empirically estimated that about 2.5σ may be sufficient to provide reserves to cover most of the intra-hour variations in Wind and Solar. Some values of deviation between consecutive time-blocks may be exceptionally high, which is dependent on the accuracy of forecast, and as such these values are considered as outliers and may be excluded from actual calculations.
Developing operational reserve requirements from variability metrics is an evolving science.This paper evaluates the reserve requirements that use current hour values of load and wind and solar generation along with forecasts of those quantities for the next time slot as inputs. Analyzing the standard deviation will help in determining the reserve requirement to cover most of the inter-hour variability due to vRE generation.
Abstract— India is keen to attempt to work towards a low carbon emission pathway. As per goal set up for Intended Nationally Determined Contribution (INDC) by India, India has to reduce the emissions intensity of its GDP by 33 to 35 per cent by 2030 from 2005 level. Harnessing Renewable energy (RE) sources is one of the attempt to work towards a low carbon pathway. Sustainable green transportation network is another measure for achieving this goal. To accelerate development and deployment of renewable energy in the country, the Government is taking a number of initiatives like, upscaling of targets for renewable energy capacity addition. Government of India has also taken multiple initiatives to promote manufacturing and adoption of electric vehicles in India. Due to variable, intermittent and non-dispatchable generation from RE sources, the safe and reliable grid operation is the next step towards the readiness for integration of such huge capacity of RE into the grid. Presently the balancing of grid for variability and intermittency of RE generation is done by ancillary services, already in place and by increasing/decreasing of generation from conventional sources. In the year 2021-22, when the capacity of RE is expected to be 175 GW (37 % of the total IC) and further upto 275 GW (44% if the IC) in the year 2026-27, some other measures needs to be identified for balancing the grid. As the % of RE generation into the grid increases, the difference in maximum and minimum load to be met from coal generation during the day will also increase. This leads to increase in ramp up & down capacity and its change in rate, reserve capacity, residual capacity, spinning reserve and balancing capacity in the grid. In order to reduce the said difference, some measures like operation of some pre identified units of coal and gas and hydro plants in the form of flexible generation may be made operational into the grid. The temporal shifting of Renewable energy generation with the help of energy storage like battery storage and pump storage may also be helpful to achieve this. Further, the flexible load in the form of flexible loads in buildings, Electric vehicle charging, may also be effective in providing flexibility to net load curve. Also, since, EVs needs charging stations to charge the batteries, the impact of EVs on power system cannot be ignored. The impact of EV charging will be felt first at local hotspots on distribution grids before the other levels i.e. generation, transmission and grid are affected. As the EV load penetration increases, their potential to contribute to flexibility services via Demand Side Response (DSR) will also increase. It can play an active role in increasing the flexibility of power systems. Electricity markets should also facilitate the EV load to participate for grid balancing. The policy and regulatory frame works are also required to be modified suitably. .
Within this work, a techno-economic optimization of large offshore wind regions, consisting of multiple concessions is developed and investigated via two case studies. One within the Belgian North-Sea and one within the Gulf of Cambay, where India’s first offshore wind project is being developed. Currently, the practice within the offshore wind industry is for countries to designate an offshore wind zone within their exclusive economic area. This zone is then further divided into individual concessions which are auctioned off to developers. Developers then optimize each individual concession independently. As such, research on electrical system optimization has been heavily focused at the scale of the individual concession, ignoring the possible gains that come from current or future developments in neighboring concessions within the same region . It is believed that there is a significant opportunity for both cost savings and increased system reliability by optimizing an entire offshore wind zone prior to the development of each individual concession .
The optimization is structured as a mixed integer linear program based on the DC power flow formulation. Typical voltage levels for AC and DC transmission are included as well as mid-point reactive power compensated AC transmission. The optimization finds a global minimum for the lifetime cost of energy. To guarantee the feasibility of the results, a full AC analysis of the proposed technical design is performed. The lifetime costs accounted for are capital expenditures related to material and labor, operating expenditures related to plant maintenance and operation, and the expected energy not served. The use of site-specific wind profiles and turbine specific power curves make for geographically and technologically relevant solutions.
To demonstrate the benefits of optimizing an entire region, two case studies are investigated. The first offshore wind zone analyzed is within the Belgian North-Sea, consisting of 10 concessions all at varying degrees of development. The zone spans an area of 175 km2 and will have a total capacity, once fully developed, exceeding 2.2 GW . The second, is one of Gujarat’s most promising offshore wind regions, “zone A”, with an area of 1921 km2 consisting of 19 subdivisions of 500 MW each . Comparing the optimal solution of the Belgian North-Sea to the existing as-built solution permits quantization of the gains to be made via the proposed optimization. Contrasting the solutions of the North-Sea and the Gulf of Cambay allows for an understanding of the impacts that different environmental and topographical conditions may have on the optimal transmission system design.
 Lumbreras et al. Wind Energy 16: 459-473 (2012)
 Ergun et al. IEEE Transactions on Sustainable Energy 3(4): 908-917 (2012)
 https://www.4coffshore.com/offshorewind/ (2019)
 Garrett et al. Pre-Feasibility Study for Offshore Wind Farm Development in Gujarat. May 2015
India has set a target to fully integrate 175 GW of renewable energy in the grid by the year 2022. Renewable energy comes with its advantage of clean energy but having a lot of unpredictability and therefore requires sufficient availability of reserves. Tertiary reserve can help restoring the frequency to a value closer to the nominal, following a sudden dip or rise in the frequency.
In India Tertiary response is being provided by Central Generating Stations whose tariff is being determined or adopted by the Central Electricity Regulatory Commission of India. The un-requisitioned surplus available in these generating stations are used to dispatch the Reserve Regulatory Ancillary Service (RRAS). However, this comes with the following challenges:
1. When the surrendering beneficiary recalls its power back from the dispatched quantum of RRAS, the quantum of power available for ancillary service reduces.
2. At times of necessity, the volume of un-requisitioned surplus may not be sufficient, to restore the frequency by the desirable magnitude.
In this paper an ancillary dispatch market mechanism is proposed so that a broader spectrum of generating stations including the Central Generating Stations can participate for the tertiary response. This will help in overcoming of the above two challenges and benefit the power system operator with better control. In the Western countries a pay-as-bid mechanism is used in the ancillary market. However, to develop a market for the Indian system a separate mechanism has been developed in this paper. The whole market based tertiary control shall involve three key steps which are as:
A. Selection of Generators: The quantum of reserve required in each 15-minute block will be known upfront by the system operator and, generator bids up to that quantum will be cleared. Uniform price will be paid to all the participating generators as per the average MCP of the energy market. This will form the fixed charge of ancillary dispatch. Introduction of a separate fund for accounting the fixed charge has been proposed in the paper.
B. Dispatch of Generators: In real time operation, based on the required quantum of ancillary dispatch, the generators will get selected in an ascending order of their bids. However, the payment to the generators will be uniform depending on the average frequency of the block of the scheduled dispatch. This will form the variable charge of the ancillary dispatch and will be cleared utilizing the Deviation pool fund maintained by the system operator.
C. Settlement based on Dispatch efficiency: A novel mechanism is introduced in this paper, where in the generators will be settled based on their actual metered energy. Using the direction of the deviation vector, the energy will be settled based on their bid in the selection process.
The adequate amount of tertiary reserve available with this mechanism will help system operator in addressing the balancing issue with high penetration of renewable energy.
Building Transactive Energy Markets (TEM) to optimize Renewable and Distributed Energy Resources grid integration:
Growth of renewables and distributed energy resources (DER) such as large scale grid connected solar plants, solar PV with batteries, storage, EV charging points etc., and flexible consumption patterns at the edge of the grid offers a new opportunity for grid operators to optimize whole-system. If regulators, policy makers and grid operators plan to optimize grid operations for the benefit of every stakeholder then it is imperative for them to optimize utilization of these flexible supply and demand resources at all levels. However, it is easier said than done because these resources are growing at the high voltage as well as at the edge (medium/low Voltage level) of network, and traditional mechanism of whole-sale market valuation (based on average estimates) and centralized control (predominantly driven by transmission & high voltage level) might not work effectively to optimize these resources. There is need of a short term balancing market supported by retail transactive energy marketplace which is enabled by a distributed intelligent systems those facilitate real-time valuation of flexible services at the edge of the grid and federated control.
The Point of View (PoV) will discuss:
What is Transactive Energy and Transactive Energy Market, and key terminologies those we need to understand such as Control Mechanism, Economic Mechanism and Value to appreciate the TEM? How transactive energy markets can enable whole system optimization?
What is the drive, value and business case such as agile renewable integrations, Totex optimization, Carbon footprint reduction etc. for grid operators and regulators to implement transactive energy markets?
What are some key use case scenarios for Transactive Energy Markets for grid operators such as:
Once the context of TEM, benefits and use cases are defined then the PoV will discuss a roadmap to establish TEM. It will showcase enterprise architecture of a smart distribution system operator with IT-OT systems such as SCADA, ADMS, OMS, DERMS, AMI, GIS, MDMS, CRM and EAM. PoV will also focus on the role of cutting edge technologies such as Artificial Intelligence, Big data analytics, IoT and Blockchain to establish transactive energy markets, promoting optimization of renewables and DERs on grid.
Other aspects such as overall policy and regulatory vision-and-objective, roles and responsibilities (system operators, aggregator etc.), transactive parties, extent and scope of transactions, settlement rules for inter and intra jurisdictions etc. will also be covered as a part of discussion.
The concluding section will define a roadmap to achieve this journey.
Integration of distributed energy resources (DER) such as photovoltaics, electric vehicles (EVs) and battery energy storage systems (BESS) is expected to rapidly increase in distribution systems in India. These grid edge resources can have adverse impacts on the grid and can provide additional revenue streams as well. To mitigate these impacts distribution planning and analysis is required. So this paper presents a framework which can be used to complete all steps involved in distribution planning and analysis. This framework uses data in the same format as is readily available with Indian utilities and processes it to generate detailed feeder models and loading profiles. This framework already includes multiple DER use cases such as peak shaving for BESS and EV demand modelling and can be easily extended to simulate a number of additional use cases. All of these use cases can be simulated in parallel for multi-year time series simulations using an integrated command line interface. A suit of grid readiness metrics are then evaluated for each simulation to determine required network upgrades and associated costs.
Electric vehicles (EVs) and distributed solar are poised to grow substantially in India in the coming years following ambitious Government of India targets. The localized impact of these changes, both in terms of infrastructure investments and demand patterns, are not well understood, nor are tools for this type of analysis readily available. This paper describes the development of a framework that can analyze network readiness in terms of feeder impacts for distributed energy resources (DERs) including growing EV penetration, and the potential solutions introduced by utility-scale battery energy storage systems (BESSs).
The building blocks of the feeder analysis require multiple data sets to be compiled into a usable network model. The work is driven by feeder head and distribution transformer (DT) loading data along with all the technical specifications and schematics of distribution feeders. These measured datasets are conditioned to remove any afflictions, and the cleaned load profiles are used to perform multi-year quasi-static time-series power flow analyses on detailed three-phase feeder models. EVs translated to grid-tied loads are represented with aggregated EV demand profile estimates based on possible charging scenarios in residential sector, and in workplace and/or public charging stations. Finally, BESSs are evaluated for their cost-effectiveness in the framework through an initial screening that includes the benefits of grid service applications to mitigate present and future overloading scenarios. The outcomes from this framework are expected to help utilities gauge the readiness of their distribution grid for integrating an increasing number of EVs as well as load growth during a projected multi-year time horizon, where BESSs can contribute in making the grid more reliable.
Wind power plants (WPP) are intermittent source of energy unlike conventional power plants, it is difficult to firmly dispatches them. Modern grid codes requires the wind power plants to be dispatched like traditional power plants, for this reason wind farm operator have to rely on prediction for short term wind power to schedule wind farm. Wind farm operators submit the bids in day ahead market based on forecasted wind power while updated wind forecast is used for hedging the bids in the electrical market. Any deviation of the actual wind power generation from the schedule wind generation is either adjusted by purchasing /selling energy in real time market, otherwise wind farm operators have to pay deviation cost as penalty. Hereby, the accuracy of the prediction system has economical and technical impact on the operation of grid with high RES penetration. In this proposed paper, comparison of three well known prediction methods like Persistence, ARIMA, Markov chain is made by evaluating the statistical metrics like mean absolute error (MAE) and root mean square error (RMSE). A well-established operating strategy min-max method is used to control the operation of the BESS connected to the wind farm. The impact of accuracy of the different method of wind forecasting on the reliability of the system is studied in this paper by evaluating reliability indices like energy served (ES), energy not served (ENS) and energy not utilised (ENU).
Fueled by Paris Agreement commitments, the Government of India has set an ambitious target of achieving 175 GW of renewable energy capacity by 2022. These include 100 GW of solar capacity addition, 60 GW of wind power capacity. Renewables being inherently intermittent sources of Power Generation, due to their dependence on weather conditions, affects the stability of grid system. Integrating such amount of an intermittent source with present-day grid, it becomes very essential to incorporate the techniques which would be helpful to maintain reliability of the grid. Ancillary Services are the services necessary to support the power system operation in maintaining power quality, reliability and security of the grid. The ancillary services current available in India, are provided by mainly coal based power plants. The POSOCO is discussing hydro as ancillary services, however no hydro power plants are providing ancillary services as on date. PSH are unique in operation. It operates as generator as well as load. Daily load curve of India has lot of peaks and valleys during a day. Though most of the states have enough generation to meet the load requirement, the variations in the load during the day are not predictable. The sudden load variations during the day makes the life of system operator miserable. Further, the stringent conditions of regional Deviation Settlement Mechanism has also increased complexity and financial burden on the states. To tackle such challenges SLDCs requires fast responding storage devices under their command and control. The existing ancillary services framework at regional level is the right step in this direction however, it is available for RLDCs and not SLDCs. Majority of power share is handled by SLDCs. India has a large potential of PSH (about 94000 MW) specifically concentrated in the western ghat region in Maharashtra and Gujrat states, where demand of both states is also very high. However, of the 94000 MW potential only 6000 MW is harnessed till date and that to some of the PSH are not operating in Pumped mode due to various technical and commercial reasons. Development of PSH is not upto the mark due to various reasons such as No standard methodology to access the economic viability of PSH project, No regulatory framework to compensate the PSH for providing ancillary services, No focused efforts by appropriate authorities to promote development of PSH by addressing the technical and environmental issues in development of PSH. As regulatory framework is not conducive, private investment is not being attracted for development of PSH besides having huge potential. If conducive regulatory environment is created, PSH could be game changer as an ideal Source for ancillary services. This Paper deals with the Technical, Commercial and Regulatory aspects of PSH towards its unique offerings in ancillary services market.
In line with the global growth of renewable energy (RE), India is also rapidly integrating wind and solar photovoltaic power to the national grid and has a current cumulative installed capacity of around 60 GW and a target of 160 GW (100 GW of solar PV and 60 GW of wind) by the year 2022. However, the variability and uncertainty associated with RE generation significantly impact power system operation, particularly, under high RE penetration. Therefore, for ensuring secure and stable grid operation under variable RE penetration, several measures for preserving the steady-state and dynamic stability of the grid have been imposed on the RE plants through grid code regulations, such as the Indian Electricity Grid Code (IEGC) applicable in India. Some of the critical provisions present in grid code regulations for RE power plants include frequency regulation, voltage ride-through capability, active power regulations, and power factor regulation.
Despite the presence of these regulations, the steady-state and dynamic operations of the plants are generally not monitored on a real-time or near real-time basis. The plants are also not put through strict compliance checks of all the prescribed criteria under operating conditions. This limitation, in turn, inherently poses a significant concern about the steady-state and dynamic stability of the grid during any contingency. The traditional Supervisory Control and Data Acquisition (SCADA) systems have a measured data update rate of around once every 4 to 6 seconds. This rate is highly inadequate to capture the system dynamics essential for analysing the dynamic performance of RE plants, studying contingency scenarios, and taking swift control actions. Therefore, in this backdrop, this paper attempts to bridge the gap by proposing a strategy to monitor the continuous operations of the RE generating stations using the network of Phasor Measurement Units (PMUs) located at various strategic and critical buses in the grid. The proposed performance monitoring strategy will enable the capture of the time-stamped dynamics at a much faster rate essential for analysing the disturbance and post-disturbance scenarios. For aiding this objective, several instances of optimal placement of PMUs have been developed by using binary particle swarm optimisation for monitoring the operations of the RE plants in the grid effectively.
Blockchain is a decentralized ledger technology. When applied to the energy sector, it will enable people to trade energy among themselves. It is a secure, continuously growing list of records. It is constructed as a decentralised database that is distributed and managed by peers, rather than by a central server or authority. This technology is enabling a new world of decentralised communication and coordination, by building the infrastructure to allow peers to safely and quickly connect with each other without a centralised intermediary. Cryptography ensures security and data integrity, while privacy remains intact. Renewable Energy is also decentralized and distributed energy source. Currently, efforts are made to integrate Renewable Energy in the grid for centralized control of Renewable Energy. This is because there is no technology available to manage and control distributed and decentralized Renewable Energy. Block Chain may provide tools to manage it locally. This may be possible for peer to peer trading of electricity produced from Renewable Energy without using any middleman. The general idea behind blockchain technology is to allow decentralisation and build security. The advantages of blockchain are increased trust and minimization of time for a process to take place. Moreover, it also removes cost overheads and intermediaries. India has set an ambitious target of 175 GW of RE in energy mix by 2022. Almost 40 percent of target has been achieved, these high level of RE in electricty mix will certainly change the way Indian Power Market Operates. This paper finds a way to formulate a power market with high RE in electricity mix in India using blockchain technology.
India aims to achieve 175 GW of renewable energy (RE) capacity by 2022. Being a climatically diverse country, India’s RE capacity addition target is highly skewed. Eight RE resource rich states of country, are having target of 74% RE capacity addition target, while in FY 2017-18 energy requirement of top eight states was about 62%.
Geographical imbalance in installed RE capacity will create a need for an eco-system which will promote inter-state RE trading. This issue has been examined under the USAID funded GTG-RISE program to enable and promote inter-state RE power exchange through developing a White Paper. The paper examines various issues in existing regulatory, transmission infrastructure and, market and commercial framework, to understand the misalignments in the operational and commercial practices, which is inhibiting inter-state RE exchange. The misalignment in regulations resulting in societal losses, while issues in transmission pricing for inter-state RE transmission posing a question mark over its sustenance and acceptability in long term to other participants of inter-state transmission corridor. Absence of ancillary market and aligned commercial framework, not allowing cost reflective engagement of balancing services for grid security. Addressing these fundamental issues will enable the creation of an eco-system which will propel RE capacity addition and its effective grid integration. The paper is an output of extensive stakeholder consultations across states including distribution utilities, nodal agencies, IPPs, transmission operators, power system operators, etc. and recommends solutions that would enable increased trading of RE power across states.
Analysis of regulatory landscape revealed how misalignment in pricing methodology among forecasting and scheduling regulations, deviation settlement, and ancillary services regulations, impacting stakeholders. Existing power purchase agreement’s commercial terms are not in sync with operational requirements like compensation for curtailment, participation in automatic generation control market for grid security. Based on the identified issues, short, medium and long term measures have been recommended, under the study.
In light of the growing pollution problem, the Government of India, over the last few years, has been increasingly promoting alternative mobility solutions, chief among which are electric vehicles. The paper analyses the impact of large scale integration of electric vehicles on the distribution network by selecting a set of sample feeders with different consumer mix in Delhi city. The number of electric vehicles in the sample feeders is projected for the year 2030 based on the available vehicle registration data, average kilometres run by each segment of vehicles, battery capacities and various electric vehicle policies by Government of India, Government of NCT Delhi, Ministry of Power, Niti Ayog reports & FAME schemes.
The selected set of sample feeders are modelled in power system simulation software MiPower™ used in most of Utilities in India. The 11/0.415 kV distribution network is modelled considering all the distribution transformers, 11kV XLPE cables and 415V XLPE cables up to pole level. Dynamic simulations are carried out for a period of 24 hours with various stochastic scenarios generated based on the characteristics of EV charging, PV generation and Battery characteristics. The following factors are analysed to find the impact of EV on distribution grid: the effect on load pattern, increase in system losses, increase in transformer loading, effect on voltage profile, network loading and augmentation, voltage regulation and maximum penetration of EVs in the network. The results and conclusions obtained from these set of sample feeders is extrapolated to the larger distribution system to assess the impact of large scale integration of electric vehicle charging infrastructure in the electricity distribution system.
The outcome of the study demonstrates that the impact of EV infrastructure on distribution grid and provides the frame work guidelines for policy and regulation authorities. For Distribution companies, it shows how EV penetration impacts the distribution network (LT network, HT network, distribution transformers) with reference to various technical parameters.
Key words: Dynamic simulation, Electric vehicles, EV charging, Grid impact.
Abstract—This paper discusses and describes the structure and operation of an energy management system, which is a part of our ongoing research work. In addition, we show the simulation results and advantages of using an energy management system (EMS) for the island of Barbados and its electrical energy needs.
This management system has the task to meet the voltage and frequency stability criterion in a grid and at the same time to find an economically optimal operating point. The structure of that system is modular. This modularity makes it easy to adapt the EMS to a given electrical grid and its power plants. So a subsequent installation of such a management system is possible. Furthermore, the EMS's modularity is important to be able to respond to newly installed or removed power plants. As a result, this system has the advantage of reacting flexibly to the number or installed capacity of power plants, wind turbines or photovoltaic systems.
The EMS has a communication link to the main producers in the electrical network and can influence the power generation about this way. It receives various information from the connected power plants, e.g., the level of hydropower plants with a reservoir or the currently active power limitation of photovoltaic systems in the event of a surplus of electrical energy. The EMS differentiates between photovoltaic systems, wind turbines, controllable loads, e.g., e-cars, conventional and regenerative power plants, e.g., coal and hydropower plant. In addition, it receives information about the current voltage and frequency in the grid. It collects all the information about the electrical grid and the connected power plants. After that, it evaluates the information with the aid of an algorithm and sends the setpoint values for the electrical power to be fed in via the communication link to the participating power plants. In the long term, each power plant then adjusts the power fed into the grid with the help of a local regulator. As a result, the EMS has an influence on the long-term electrical energy fed into the grid by the power plants. For the long-term control, which is responsible for determining the economically optimal operating point, there are two levels of control. The top level is the energy management system with its algorithm followed by the local controllers of the participating power plants. Short-term load transients or effects of larger short circuits are compensated by the Droop Characteristic in the local controllers.
Keywords—hybrid power system, energy management system, grid stability, economically optimal operation point.
We evaluate the degree to which the wholesale market value of solar PV electricity (VOS) increases when a demand-side management (DSM) measure using air conditioners with cool thermal energy storage (CTES) is implemented at different gross solar PV shares. We examine two DSM measures with different maximum DSM durations, efficiencies and costs namely, mechanical precooling of the building thermal mass using programmable thermostats here called in short, Precooling, and chilled water storage (CWS). Using the open-source power sector model DIETER, we first we quantify the decline in the Wholesale VOS with increasing gross solar PV shares in the final electricity demand for a reference scenario. Next, we quantify change in the wholesale VOS due to our DSM measures compared to our reference scenario in a highly-air-conditioned and low-carbon Indian power system in 2040 under a carbon price of 50 USD/tCO2. We show that the Wholesale VOS declines from 89 USD per MWh at 1 % solar share to less than 10 USD per MWh at 60 % solar shares in our reference scenario driven by a decrease in wholesale electricity prices while solar generation is abundant and an increase in solar curtailment. Precooling and CWS increase the wholesale VOS up to 18 USD per MWh and 26 USD per MWh compared to our reference scenario respectively by improving the matching between solar generation and AC demand profiles, which leads to increased solar-coincident wholesale electricity prices and reduced curtailment.
Intermittency and uncertainty associated with renewable energy sources (RES) such as solar and wind would create generation load imbalances and have an adverse impact on system frequency. These impacts lead to recurring events of frequency deviation followed by inevitable contingencies and may endanger system security. The initial frequency deviation can be arrested by system inertia (SI) and primary frequency response (PFR). Large system imbalance requires additional PFR response. In this context, this paper investigates the potential of pumped hydro energy storage (PHES) to maintain frequency stability under large RES integration. Generation scheduling is performed for the day-ahead, to estimate the PFR adequacy. The study envisages the role of PHES for inertial response and PFR, to mitigate generation-demand balance followed by a sudden loss of the largest generation unit. Frequency security parameters like the rate of change of frequency (RoCoF), nadir frequency and quasi-steady-state frequency value are examined for PFR adequacy assessment. Case studies are carried out on a New-England 10 machine test system, to demonstrate the efficacy of the proposed model.
Growing penetration of Distributed Energy Resources (DERs) and Renewable Energy (RE) in the Indian network is leading to several changes in the system operation. Due to these changes, coordinating operation of the entire power system has become complex. A Virtual Power Plant (VPP) can be one of the effective solutions to manage this transformation. VPP is a portfolio of DERs, which are connected by a control system based on Information and Communication Technology (ICT) . A VPP aggregates the capacity of many diverse DERs and creates a single operating profile from grid’s perspective. This paper will describe the usefulness and opportunities of VPP in India. In addition to discussing the definition and types of VPP existing across the globe, the paper will also highlight the general benefits of VPP for different entities across the electricity supply chain. The paper is segmented into four sections: (i) Defining VPP and its type, (ii) Relevance and plausible schemes of VPP in India, (iii) Example illustrating an opportunity for VPP in India, and (iv) Recommendations and way forward for the Indian market to adopt VPP technology.
The objective of the paper is to give an insight to the readers about this concept and to provide a perspective to the Indian stakeholders for considering the implementation of VPP.
In the recent years, the worldwide grid integration of renewable energy sources (RES) has grown rapidly. However, the grid-integration of large volume of renewables like wind and solar, interfaced by power electronics converters, is changing the dynamics of the power system and creating challenges to maintain reliability, robustness and stability of electricity supply. Morevoer, the stronger inter-linking of networks poses a greater risk of wide-area blackouts. With the growing share of wind power in the grid and conventional generators being phased out, large offshore wind power plants (OWPP) with state-of-the-art wind turbines (WT) can provide services of blackstart and power system restoration (PSR) in the future. This paper provides an overview of the technical
requirements of blackstart units and the current capabilities of WTs, based on grid-codes, studies on ancillary services and recent blackout experience. Finally recommendations to the functional requirements of WTs are made, to make OWPPs capable of blackstart and help facilitate PSR in the future.
Due to high wind speed and high plant load factor in deep oceans, coupled with a saturation of onshore space, offshore wind farms (OWF) are being rapidly integrated into power systems. Several countries are investing more in OWF sector with consistent increase in penetration of voltage source converter-based high voltage DC connected OWF in these countries. Due to significant penetration of OWFs, such countries have developed separate grid code regulations, including low voltage ride-through (LVRT) capability for OWF connection. The OWF, according to LVRT requirement, should stay connected and support the electric grid during LVRT period. One of the critical issues of LVRT capability of HVDC connected OWF is that the OWF cannot inherently detect the faults in the onshore grid, which results in overvoltage in the HVDC link during onshore low voltage faults. Most of the previous LVRT studies on OWF did not consider active power recovery (APR), and none of the reported study has considered voltage dip induced frequency (VDIF) issue. This paper investigates the effect of APR ramp rate on the VDIF response in OWF integrated system. Modified IEEE 39 bus system has been used as a test system and the system performance is evaluated under different case studies, such as, various OWF penetration levels, different fault severity and fault duration.
Ambitious targets for climate-change mitigation and energy sufficiency lead to rising share of renewable energy (RE) in generation mix. With future market scenario and potential of large-scale deployment, major contribution is provided by solar and wind RE sources. However, their intermittent nature not only increases the variability and uncertainty in power system but also deteriorates its performance in many technical and economic aspects such as frequent load & RE curtailment, decreased capacity utilization and increased operating cost of conventional generating units. For smooth integration of RE, grid planners need to ensure that enough flexible options are available down the road that will help to maintain system reliability without deteriorating the performance of conventional units. In this regard, this paper formulates a security-constrained unit commitment (SCUC) problem for a whole year in rolling horizon and performs techno-economic benefit analysis of energy storage system (ESS) to facilitate high RE integration. System benefits are accounted in-terms of reduced system operating cost, increased RE penetration & capacity utilization factor, and reduced CO2 emissions.
In India, the geographical conditions are varied, and the characteristics of dust depend on the local environmental conditions. The solar power generators must incorporate the soiling losses in their estimation for power output. An attempt to develop a methodology to estimate the soiling correction factor was made. The methodology implemented was research of previous studies on soiling, monitoring and analysis of 20 kW rooftop solar power plant and an experiment to estimate the soiling losses. Extensive research was carried out and a comprehensive review was presented on the effect of soiling on performance of PV plants along with case studies of soiling experiments in India and around the world. A soiling experiment was designed to develop the soiling correction factor. A methodology to calculate the soiling correction factor was developed by analyzing the data from the soiling experiment. The effect of rainfall, humidity and wind on soiling have been analyzed and documented. The performance of one 20 kWp PV plant was monitored to study the effect of weather-related parameters on the performance. The soiling correction factor varied from -1.36% to 3.67% during the period between June 2018 and June 2019 in Chennai. It was observed that the average PV conversion efficiency of the 20-kW plant was 11.75% and the average PR was 75%. It was observed that the correlation between module temperature and DC power; between humidity and DC power; between humidity and DC power varied every month. The R² values for each correlation has been tabulated in this paper. The soiling factor developed was incorporated into the short-term day ahead solar forecasting model. The developed methodology can be applied at the sites of large-scale solar power plants for yield assessment, designing as well as operational forecasting purposes.
Share of RE in total installed capacity (350 GW) has reached over 21% and it is bound to go up as we move towards the ambitious target of 175 GW RE set by the Government of India (GoI). Climate change commitments and increased competitiveness of RE with conventional power indicates that RE will have a significant share in country’s installed capacity in long term as well.
Electricity markets have a vital role to play in integration of Renewable Energy (RE), particularly in view of positive RE growth outlook in medium to long term. The country today has a well-functioning Day Ahead Market (DAM) where substantial trades take place, providing price signals to both the demand and the supply side. However, beyond the DAM, other market forms like term-ahead and intra-day markets have not met with adequate success. Currently, the overall system relies largely on long term contracts and a scheduling mechanism where load serving entities and eligible customers schedule their own portfolio and also buy from the market on the margin. Imbalances are settled through the Unscheduled Interchange (UI)/ Deviation Settlement Mechanism (DSM) under an administered process from which India has begun to graduate to Ancillary Services (AS) markets.
The fast paced RE capacity addition necessitates relook at the current market design to mitigate the challenges emanating from ingress of variable and intermittent RE generation. Market design interventions require changes beginning with the current planning approaches, to signal how much RE can be economically and securely absorbed by the grid, along the need for network augmentation and operational changes. The Ancillary Services and Real Time markets must be robust to ensure effective mechanisms for handling and settlement of imbalances.
To layout a roadmap for electricity markets of the future, KPMG in India has undertaken a national workshop series, under the ‘Power Sector Reforms Programme’ supported by Department for International Development (DFID) and Ministry of Power (MoP). The series comprised consultation and exchange of ideas with a large number of stakeholders, market players, policy makers, regulators and experts and has led to identification of key challenges, priorities and actions for effecting changes in current market design.
The proposed paper intends to highlight the outcomes of the workshop series which aims to guide the policy makers in steering the market design changes, many of which will be critical for enabling large scale integration of RE. The paper will lay out the key challenges, market design options, international experience, stakeholder perspectives and imperatives for ushering in electricity markets of the future.
As India moves towards its target of 175GW power supply from renewable energy (RE) sources, it is imperative to have flexible power supply to balance intermittency in RE generation. A large part of this balancing capacity needs to come from Indian coal plants along with other solutions such as large scale energy storage, demand side management efforts etc. In order to manage intermittency from high RE generation, coal based power plants should be flexible to operate at - (a) low loads, (b) faster ramp rates and (c) rapidly start up or stop based on grid requirements. Since these plants were designed to operate as baseload power plants, retrofitting of components and/or operational changes are required to make these existing coal plants flexible.
Coal plants in several countries with high share of RE penetration have undertaken initiatives to enable flexible operation and have achieved remarkable results like reduction in minimum load to 10-30%, increase in ramp rate to 2%-6%/minute, and significantly reduction in cold- start up time to 75 minutes. For instance, Ratcliffe plant in UK regularly starts/stops for up to 2 times/day; Heyden plant in Germany can operate 10% of capacity for several hours.
To contextualize and customize the interventions for the Indian market, KPMG along with DFID, Ministry of Power, APGENCO and Uniper undertook a pilot study in Andhra Pradesh (high RE state), primarily to evaluate the extent of flexibilization required and intervention needed to achieve target level of flexibility. At 18GW RE capacity Andhra Pradesh state is expected to face large scale RE curtailment (upto 20% in 2022) if Minimum technical Limit (MTL) aren’t reduced below 55%, however if MTL is reduced to 30% there would be <2% RE curtailment.
For the pilot, Sri Damodar Sanjevaiah thermal power station (SDSTPS) was chosen. As a middle of merit order dispatch plant, SDSTPS needs both low load operation and rapid ramping. Based on the diagnostic visit, a roadmap was developed to achieve flexible operation covering existing technical issues like improvement in flame detection, modification to address low back end temperature, design changes to enable TDBFP operations at low load, enabler actions like implementation of CMMs systems & capacity building for staff. As a first step the initial focus should be on reducing minimum load, with initiatives to improve ramp rate also done in parallel. Improving stop – start (2 shift) ability would be taken up as a future target, after successful delivery of the first two priority areas. The broad estimates for such a program would be in the range of $7-8 million/unit which shall be further refined based on trials and detailed cost-benefit analysis.
In addition to developing technical guidelines, the study will also provide recommendation on regulatory, policy & and market incentives which are needed to encourage & compensate power plant operators for investments needed to enable flexibilization measures.
Government of India has set a Solar Roof Top (SRT) capacity target of 40 GW by 2022. While SRT installations in the industrial and commercial segments have gained momentum owing to cost benefit and attractiveness of this customer segment for developers/ financiers, traction for these installations in the residential segment remain low due to a variety of reasons including weak business models, customer aggregation challenges, multiple stakeholder involvement in obtaining consents and clearances, higher perceived default risk, lack of innovative financing mechanisms etc. In order to resolve these issues, it is imperative for the Utilities to support SRT installations for the residential segment. Key benefit for Utility shall be reduced subsidy burden on low end domestic customers.
‘Utility driven solar rooftop pilot’ is one activities undertaken through the ‘Power Sector Reform (PSR)’ technical assistance programme undertaken by the Government of UK and Government of India. This activity aims to develop a model framework for a Utility driven SRT model targeting subsidized residential customers and implement a pilot scheme in one or two cities in Andhra Pradesh to demonstrate the concept and the model.
The proposed paper aims to present the one of its kind model developed for implementation by distribution utilities in India. The models includes the structure, risk mitigation meachnism and estimated savings etc.
With renewable sources like wind energy gaining traction in the energy market, the study of operational reliability of such sources warrants substantial importance. Despite it being environmentally friendly, wind energy, mainly because of its inherent stochastic nature brings critical challenges such as stability, reliability and power quality issues. With intermittent and variable nature of wind, integration of such generation sources introduces several challenges in secure and stable grid operation, with reliability of such generation resources being one of the major concerns. Therefore, this study aims to quantify impact of failure of Wind Turbines (WT) and randomness of wind, both in terms of velocity and direction, on the performance of wind farms.
The influence of wake effect is highly correlated to the distance between turbines in a given wind farm, with WTs placed closer together facing more pronounced wake effect than turbines placed further apart. On changing the direction of incoming wind, the distance between WTs, along the direction of wind changes, thus leading to a variable wake profile depending on the velocity and direction of wind. So, in order to generate a realistic scenario, both wind speed and wind direction needs to be considered in performance evaluation of wind farm.
Further, WTs may also face random failures, particularly in harsh offshore wind conditions. As, such in any particular time a turbine may be either operational or in an off state. Also, once a WT fails, it remains un-operational for a certain minimum downtime before it is operational again. During this period when the WT is un-operational, it also does not produce any wake on its downstream WTs. Turbine failure is greatly dependent on wind speeds, and under higher wind speed scenarios, probability of WT failure increases considerably. In this study, reliability indices such as Loss Of Load Percentage (LOLP), Expected Energy Not Supplied (EENS) and Expected Demand Not Supplied (EDNS) have been used.
Owing to the random nature of both wind unpredictability and the failure of WT, this study will estimate reliability of the wind farm considering wind direction, wind speed and random WT failure.
Renewable energy sources are becoming cost effective and are presented as cleaner source of electricity generation. Increasing penetration of such intermittent resources may pose significant challenges in power system operations due to their variability and uncertainty. Steeper net load ramps or unexpected variations in RE generation may leave controllable units with insufficient generation and/or ramping incapability and create load-generation imbalances in real-time. This necessitates flexibility requirements in power systems. Many system operators have introduced market-based flexibility products to address the ramp requirements in realtime operations. This paper aims to model such market based flexible ramp product (FRP) from pumped hydro energy storage (PHES). A MILP based 15-minute temporal day-ahead security constrained unit commitment and 5-minute redispatch with the co-optimization of energy, reserve and FRP are formulated for the studies. Further, benefits associated with utilizing PHES for flexibility provision are analysed.
Effectiveness of proposed model is studied on IEEE RTS 24 bus test system using GAMS 24.2.3.
Efforts are underway to assess the way forward for integrating the South Asia Countries in a common energy market. To start, the focus would be on India, Bangladesh, Nepal, and Bhutan, since these countries are already connected to the Indian Power Grid, and also have diverse and complementary generation resources which could provide synergy in operations. In view of achieving the maximum economic and environmental benefits of integrating these countries as a common market, the planning process needs to be robust and all-inclusive, especially due to high vRE penetration expected in the region in the near future.
Any planning process intended to efficiently achieve the goal of regional market integration should start with the development of a comprehensive Regional Power Development Plan (RPDP), founded on the pillars of (i)determining the long-term generation requirements for the region and assessing the transmission and other related infrastructure requirements to support the regional operations, (ii)identification of the policy and regulatory provisions to govern the integrated market, (iii)formulating the payments and settlement methodology for the market participants under various categories, and (iv)facilitating in setting up Institutions responsible to carry out the market operations and settlements.
In line with the pillars of RPDP development, this paper provides an overview of the roadmap from a planning perspective for achieving the optimum benefit of integrating and operating the South Asia countries as a common energy market, starting with possible methods to design an integrated long-term generation plan considering the projections/requirements for each country, followed by the capacity assessment of intra-country and inter-country transmission lines to cater to the long-term market requirements.
A major focus area is to ensure that the RPDP is prepared in order to ensure that the maximum generation from vRE sources in the countries can be utilized, with sufficient conventional generation with necessary ramping capabilities is available to counter the variability of the vRE resources. To achieve this goal, this paper outlines a template of the RPDP preparation methodology, which needs to include aspects related to the generation capacity expansion planning over the long term to determine the capacity required to meet the demand at regional level as well as for individual country. The expansion planning provides inputs which would then be utilized in production simulations for individual countries and on a regional basis to determine the optimum operational methodology in terms of system costs. Another important analysis in this respect is regarding the system reliability in view of the high vRE penetration. Furthermore, the transmission capacity expansion requirements can also be ascertained through the same exercise on a regional operation basis, which would be in terms of the transient stability and/or frequency response analysis.
The stochastic behaviour of modern generation systems poses a formidable challenge for System Operator (SO) to maintain generation-demand balance. This imbalance should be corrected within a short span of time otherwise, system frequency would vary from the nominal value. Large frequency variations due to contingency, like generation outage or loss of load, may cause serious threats to stability and security of the system. This necessitates a wider understanding of the research challenges arising out of large penetration of Renewable Energy Sources (RES) in the grid and requires evolving system technologies and modelling to maintain reliable and secure system operation. This research attempts to develop a mechanism for PFR adequacy with the large integration of uncertain wind generation sources. A novel stochastic security constrained economic dispatch framework is proposed for the assessment of role and value of available and required PFR mapped with frequency security criteria like Rate of Change of Frequency (ROCOF) and Frequency Nadir. This addresses multiple concerns associated with PFR adequacy such as comprehensive modeling of dynamic frequency evolution after contingency, uncertainty characterization, and representation in system operation.
Wind and Solar PV (SPV) projects which were developed and operated on standalone basis normally have low capacity utilization due to seasonal and daily variations of the resource. In India, wind and SPV generation outputs complement each other and thus a wind solar hybrid plant’s output has a much higher capacity utilization over a period. Addition of Battery Energy Storage System (BESS) further augments benefits achieved out of co-locating wind and SPV plants. There are several advantages of developing Wind, SPV and BESS hybrid projects to the ‘Operating Utility’ and the ‘Developer’ as well. Transmission infrastructure optimization, lower project development costs, distributed O&M and security costs, frequency support to grid, better RE forecasting and reduction of ramping requirements from coal plants are some of the advantages that hybrid projects offer. BESS have numerous applications at different levels viz. generation, transmission, distribution and at a customer site. At generation level, BESS may be used for power or an energy application which is characterized by the duration of discharge. Primary frequency response, spinning and non-spinning reserves, energy arbitrage, avoiding RE curtailment, RE plant output firming and black start capability are few examples of BESS application on generation side.
This paper discusses the financial evaluation methodology and business cases for BESS at generation level for Wind, SPV and BESS hybrid project located at in the state of Andhra Pradesh, India. It describes a relevant portion of a larger study completed in April 2016. Business cases are developed for each of the BESS’s applications viz. reducing penalty on account of Deviation Settlement Mechanism (DSM), Peak shifting and RE forecasting error impact reduction (RE plant firming). BESS is designed (technology and rating) for each application and generates annual revenue stream depending on the application considered. The evaluation is based on the Levelized Cost of Electricity (LCoE) and a benchmark level of Equity IRR (EIRR). Considering higher costs of BESS in year 2016, Viability Gap Funding (VGF) requirement were computed for each of the business cases where EIRR was less than 16%. In addition to VGF, Generation Based Incentives (GBI) and Subsidy requirements were also computed as a tool to make a project feasible option. It is observed that, the LCoE of BESS is very high on standalone basis however when considered in combination with Wind and SPV, overall project LCoE is reasonable. BESS application of DSM and peak shifting are feasible however for 16% EIRR there was a requirement of VGF support in first two phases of project. RE forecasting error reduction application is attractive if forecasting error is more than 15%. For current levels of forecasting errors, IRR was not found attractive. Finally, business models are re-run and results are re-computed with estimated current levels of capital and operating costs for the BESS system.
The increasing trend to integrate intermittent wind generation in restructured power systems introduces several operational issues including reserve management and market performance. Therefore, Very Short-Term Forecasting (VSTF) of wind speeds is highly emphasized to address these issues by accurate predication of Wind Farms’ (WFs) power outputs. State-of-the-art of VSTF typically provides a trade-off between machine learning and time series techniques. This paper provides an exhaustive study of statistical and machine learning VSTF models, i.e., linear regression, Autoregressive Integrated Moving Average (ARIMA), k-Nearest Neighbors (k-NN) and Artificial Neural Network (ANN). The performance of these models is evaluated by Root Mean Square Error (RMSE) and Mean Absolute Error (MAE). The study is carried out on the dataset of WF located at Jaisalmer, Rajasthan, India. The results obtained concludes that ANN outperform for VSTF of wind speed because of its ability to form complex non-linear systems for forecasting based on simple wind speed data. The ANN forecast accuracy is followed by linear regression, ARIMA and k-NN models.
Renewable energy sources (RES) are the best alternative to meet the requirement of increasing energy demand. In India, RES is abundant and generation share from these sources has shown tremendous growth in the recent year. Now a days, about 33% of India's primary energy consumptions is full fill by RES. In the last two and half decades, there has been a vigorous pursuit of activities relating to research, development, demonstration, production and application of a variety of RES technologies for use in different sectors. The objective of this work is to estimate the potential of grid quality solar photovoltaic power in Jodhpur district of Rajasthan and finally develops a system based on the potential estimations made for a chosen area of 100m² (1076.4sq.ft.). Equipment specifications are provided based on the availability of the components in India. Moreover, the cost estimation of grid-connected SPV power plant is discussed to show economic viability.
Declining costs of Lithium-based batteries can enable grid-scale storage to provide peaking capacity and energy balancing services, especially to systems with high variable renewable energy shares. Using a new capacity expansion model with high spatial and temporal resolution, we examine cost-optimal investments in generation and storage capacity for high renewable energy scenarios in India. While energy generation from both wind and solar photovoltaic technologies is becoming increasingly cost-competitive with India's traditionally dominant coal-based generation, low-cost battery storage will be key to a cost-effective transition towards deep decarbonization.
This paper presents a game theoretic bidding strategy approach is proposed for the assessment of bidding strategy of WPPs in a uniform price based day-ahead oligopolistic electricity market considering rival behavior. Strategic interaction between WPPs is modeled through stochastic Cournot model. Wind power uncertainty is represented through scenarios, which are generated and reduced using scenario generation & reduction algorithms. Payoff of each WPP is calculated considering market clearing price (MCP) and imbalance charges obtained using inverse demand curve and imbalance price mechanisms, respectively. Single and dual imbalance price mechanisms are used in the evolving electricity markets. Nash equilibrium is the solution of the proposed approach that provides optimal bids for strategic WPPs considering rival behavior. The proposed approach is illustrated through a practical case study of WPPs. The influence of the different type of imbalance price mechanisms and increasing wind power penetration on WPPs’ profit is analyzed.
The power sector in India is in a state of flux. Some of the reasons for the flux are global phenomena such as reducing RE and storage prices and advances in smart grid infrastructure, while others are specific to the policy and regulatory environment in India such as the move to universal access to electricity, migration of large consumers to open access and captive options, stranded generation capacity and financial situation of distribution companies. These changes have significant implications for generation and transmission capacity planning, regulations and grid operations. However, there is considerable uncertainty in how these changes will pan out over time since a lot of factors that affect these changes are beyond the control of system planners. In this context, appropriately set up power sector models provide significant insights that can help formulate better strategies and make more informed decisions. We describe a production cost simulation model for the state of Maharashtra for the year 2029-30, and illustrate some initial insights that are relevant for electricity planners, distribution utilities, regulators and system operators in Maharashtra as well as the rest of India.
Based on a power system model, this paper studies how different policy decision evolve the future Indian electricity system of the year 2040. As of 2017, fossil fuels provided 80% of the electricity generation in India and there is a critical concern of increasing emissions in the future with steady increase in demand. To overcome this concern, the Indian Government promotes the greening of the electricity system by setting renewable energy addition targets and other favourable policies. This paper mainly focuses on the long-term goal set in the draft national energy policy 2017, aiming 36% renewable energy in the power generation mix in 2040.
The paper studies the current India electricity system, and the Government plans related to its future. Using the collected data, the electricity system is modelled in the simulation software called ‘BALMOREL’ and scenarios expressing the stated policy and different levels of climate policies in the Indian electricity system of 2040 are simulated. The developed model includes the latest and detailed representation of the Indian power system.
The paper studies four scenarios. Stated Policy Scenario studies how the Indian electricity system develops under the stated policies of the Government. The ‘Carbon Price Scenario’ analyses the effect of the introduction of a price on CO2 emissions on the renewable energy contribution in the power system. The ‘2 C Scenario’ shows a cost-effective way for the evolution of the Indian power system in 2040 to achieve the above long-term Paris goal of 2°C by 2100.
The main results of this study are as follows. By 2040, the Government target of having a share of 36% renewable energy in the generation mix can be achieved with negligible curtailment. The cost-optimal capacity of solar and wind power required to achieve 36% RE share are 256 GW and 204 GW respectively. Pump storage and Hydropower with reservoirs are the main sources of flexibility in the system. Emissions from the power system increase to 1817 Mt CO2 by 2040 due to the increase in the coal power generation to meet the increased electricity demand.
RE contribution to the generation mix in 2040 will be only 21% if RE growth is promoted by market forces alone without any government interventions. Introduction of 35$/ton CO2 carbon tax reduced the power sector CO2 emission level in 2040 to 750 Mt, a reduction of 60% compared to Stated Policy scenario. RE share in generation mix increases to 48% with the introduction of the carbon tax. With the increased RE share of 48% causes curtailment of the RE power. 1.1 % of wind and 0.03% of solar power are curtailed. A cost optimum way to achieve a power sector in 2040 adhering to the long-term Paris goal of keeping the temperature rise below 2 °C by 2100 is to reduce the coal generation to 14% share, nuclear providing 21%, hydro 16% and RE 46%. An introduction of a carbon tax of 39$/ton CO2 by 2040 as policy measure could also help the Indian power system to adhere 2 °C goal.
India has already embarked on an ambitious program to significantly increase the proportion of solar energy on their grid. Solar is a variable renewable energy resource (VRE) that requires additional power system flexibility to balance the grid especially under higher penetration of VRE. Solar power plants can be operated flexibly to address this operating challenge. In this paper we describe a simulation study conducted for a relatively small utility system that quantifies the value of this solar flexibility. The study finds that once solar penetration exceeds 14% of annual energy supply, the operating reserves needed to accommodate solar uncertainty necessitates increased solar curtailment to avoid oversupply during low demand periods. As the penetration continues to grow, flexible solar reduces uncertainty, enables leaner operations and provides significant economic value. At penetration levels exceeding 20%, by operating solar in a fully flexible manner solar curtailment is reduced by more than half. This creates significant additional value resulting from reduced fuel costs, operations and maintenance costs, and air emissions.
For the transformation of the electricity system to a renewable energy system it will be necessary to expand the grid and to increase the storage capacities. Pumped hydro energy storage systems are currently and will be the dominant storage technology to store surplus energy in the future. A major challenge for the further expansion of conventional pumped hydro energy systems on land is the identification of suitable and conflict-free locations. The development of an offshore pumped hydro storage concept, which was tested for the first time at the Fraunhofer Institute for Energy Economics and Energy Systems technology IEE (former IWES Kassel) in the project StEnSEA (Storing Energy at sea), could enable the use of new locations at sea. The main requirement for this new technology is a sufficient depth of water at a small distance to the shore. Based on a feasibility study, the StEnSEA project carried out a detailed system analysis with the development of the design, construction and logistics concept. Additionally the pump turbine unit itself and its integration into the storage system has been investigated. Furthermore the integration into the electricity network has been analyzed and a techno-economic assessment has been carried out to develop a roadmap for the technical implementation of the novel offshore storage systems. A major part of the project was the installation of a prototype in scale 1:10, which was successfully tested in the winter of 2016 in Lake Constance. Apart from the huge worldwide potential, another main advantage of the offshore pumped hydro storage system is that the power of the system can be adjusted by the number of units installed in a plant. This enables various operating concepts for the application of the offshore pumped hydro storage system, which could cause this new technology to be an important part of the future energy supply.
Keywords: Energy Storage, Pumped Hydro, integration of VG
Hybrid system is a form of distributed generation technology that is located very close to the consumers and operates optimally with the utility grid to provide a sustainable power solution at the load points. The hybrid system is signed by independent power providers to harnesses energy from numerous renewable energy technologies and provides storage capabilities with the application of battery system. The power solution power solution provides by the hybrid system is cost-effective and efficient as well as improves the entire system capacity, security and reliability. Solar or wind power alone can fluctuate, but the perfect solution is to combine two or more forms of energy sources to provide a reliable source of energy. The stochastic nature of renewable energy sources has instrumented to a choice of multiple configurations with diverse generation technologies and battery system for sustainable power solution. Hybrid system is required to ensure reliability of power system and for peak shaving applications, improving the voltage level or connecting isolated areas that are far from the utility grid. This paper will show the modeling of a PV system from solar panels, DC-DC converter, inverter and until the system is grid connected to feeder X to improve the voltage levels of this feeder as it has low voltages, the circuit will be modeled on PSIM and Power factory software.
The advent of smart grid provided ample opportunities for consumers to adopt small-scale renewable energy generation and become prosumers. In addition to this, advancement in information, communication and control technologies has equipped prosumers with smart home appliances. To extract energy saving and lesser cost of electricity, residential prosumers perform energy management in accordance with renewable energy generation, energy storage, responsive appliances, and electricity price. This requires optimal scheduling of prosumer demand with their operational preferences of appliances in order to perform energy saving. In this regard, this paper proposes a novel optimization based control of different (characteristics) appliances to schedule electricity for residential prosumers. Prosumer demand preferences for appliances are considered with operational constraints of appliances. Time-of-use tariff and dayahead real time pricing is used for electricity scheduling and its impact is assessed. To increase the energy efficiency and the accuracy of the required results, scheduling time horizon of 24 h is divided into 144 small time slots, each of 10 min duration. The simulation results show the reduction in the cost of electricity and attainment of the highest possible satisfaction level of prosumers.
With increasing RE generation getting into the grid the behavior and response of grid is going to be changed. The present grids have RE percentage of 10% which is going to be 30% by year 2022.
The RE Generation is stiffer from dynamic and transient response point of view. Also RE being inform power and directly proportional to environment and atmosphere conditions.
As the percentage of RE will increase the fault level at grid will change. The behavior of power electronics is different from rotating machines. The electromagnetic behavior is different and together there will be a great impact on the grid inertia with increasing RE generation.
Another major change which is happening is the distribution feeders will start behaving like supply feeders for some part of the day and consumer of power for balance period of the day. The system needs to be made suitable for bidirectional power flow.
The paper discuses all the above issues and preparedness for change in grid codes and practices for making grid future ready.
Intermittent and uncertain generation characteristics of renewable energy sources (RES) impacts decision-making problem of load serving entity (LSE). LSE makes procurement and dynamic sale price decisions well in advance to maximize its profit. It procures energy from available RES generation along with wholesale electricity market (WEM) and bilateral contracts. WEM market price uncertainty introduces volatility in procurement cost that makes LSE’s profit risky. Therefore, LSE determines a trade-off between profit and risk. In this perspective, this paper put forwards an exposition of energy procurement strategy and dynamic sale price setting for RES penetration, with consideration of WEM price uncertainty. LSE’s risk aversion is modeled by mean-variance technique, to obtain the trade-off between profit and risk. Case study is conducted to highlight impact of RES availability on LSE’s sale price and procurement decisions. Simulation results show that during RES generation availability, LSE offers lower sale prices and would result in consumer demand shift within these hours. This strategy would enhance RES utilization.
Power system reliability under increased RE penetration is of significant concern to system operators. As of now in India, the regulations on tertiary reserve market exist, and are followed by Regional Load Dispatch Centres (RLDCs). Considering the future growth of RE to meet the Government of India (GoI) targets, regulation reserves have been identified as necessary to compensate variations due to the load and RE in the seconds timeframe. Under the pilot, the AGC facilities are planned to implement at two hydro power plants: Sharavathi hydro power plant (10x103.5 MW) and Varahi Hydro power plant (4x115 MW). The existing AGC module in Energy Management System (EMS) at State Load Dispatch Center (SLDC) is planned to configure to generate the AGC signals for participated hydro units. The paper will analyse the role of ancillary services with focus on secondary control using Automatic Generation Control (AGC).
Keywords: Automatic Generation Control, Ancillary services, Energy Management System, Hydro power plants
India has set exceptionally ambitious renewable energy (RE) targets including 175 gigawatts (GW) of renewables by 2022 and to achieve 40% of electric power installed capacity from non-fossil fuels by 2030. Such ambitious targets invariably encounter various new headwindsand challenges. Recent months have brought some of these to the fore, including questions over the grid capacity to incorporate a rapidly rising variable energy penetration so quickly.
India’s electricity supply has historically been largely coal dominated, with 191GW currently operational. In the last 2-3 years the share of solar and wind generation, although low, has been increasing rapidly. This focus on the deployment of more variable renewable energy generation - a result of India’s transformation of the national electricity system to diversify generation into more sustainable, lower cost, domestic sources – also brings additional load balancing pressures.
In a recent report by CEA on RE integration, presents that in a situation if India will achieve 175 GW of RE capacity by 2022, on the best RE generation day, the maximum generation will be ~108 GW. During such time period, coal-fired power plant will have to operate at a minimum load factor of as low as 26%. Indian coal-fired power plants are not designed to operate at such low load factors and will require massive support from gas, PHS, battery storage and grid connectivity to manage this evolution.
India’s electricity pricing mechanism should ideal provide some long term financial incentivisation of storage and firming capacity projects to ensure uninterrupted power supply, be that fast ramping coal power, gas peakers, distributed as well as utility scale batteries, hydro-electricity, pumped hydro storage, and demand response management. An ancillary service market with products like leakers-active and reactive power support, frequency regulation and ramp rates needs to be developed.
In this paper, we will explore the need for creating a market that provides signals for balancing capacity and flexible generation to balance power supply and demand, particularly in meeting peak demand. The analysis will cover a commentary on demand and supply side responses that can meet the peaking and flexing needs of Indian energy systems and the policy design that can enable setting up of such capacity. What kind of regulatory interventions will facilitate the transition to clean energy in an effective and least cost way.
Also, analyse few international case studies to highlight the various technologies and adoption of market structure to manage the increasing share of renewables in their electricity mix. India is well placed to become a world leader in deployment of various RE technologies and storage, given right market structures are in place. Based on other country’s experience and study of local conditions, this paper will attempt to provide a roadmap for faster deployment of RE as a reliable power.
In India, electric mobility is currently at its infancy. At the crossroads of this possible market disruption is the electricity sector. While additional electricity sales due to Electric Vehicle (EV) charging would help increase the revenue volume of an electricity distribution utility, charging demand may accentuate the peak load of the service area and have a bearing on the cost of power procurement for the distribution utility. Thus, it becomes essential to evaluate the additional electricity demand from EV adoption, its possible pattern and contribution to base and peak load. This will enable DISCOMs to operate its distribution network efficiently and the State Electricity Regulatory Commissions to introduce appropriate instruments to avoid any negative impact on the electricity supply. This study models the peak and off-peak contribution from EV charging and estimates the impact on the cost of power procurement of electricity utilities in a state. The study finds that EV charging significantly increases the energy consumption from 12 AM to 6 AM. The study also finds that the number of EVs which can potentially impact the average cost of supply varies across different DISCOMs.
Utilities all over the world have developed comprehensive interconnection rules and grid codes that require wind power plants to have similar operational characteristics to conventional generation. A major component of these requirements is the supply of reactive current during faults. A common starting point in the development of reactive current requirements is to prioritize reactive current without specifying a minimum amount in relation to a change in voltage. The new Indian grid code is an example of this nonspecific reactive current requirement. Other regions, such as the UK, Australia and Jordan, have implemented a more specific requirement where the amount of reactive current injection is defined in relation to changes in voltage. In this paper, the Jordanian grid code is used as an example to demonstrate the use of a STATCOM at a large-scale wind power plants to meet specific reactive current requirements.
Seasonal and daily mismatches in variable renewable energy (VRE) and loads have led to a wider range of operating voltages on feeders. This has introduced new voltage management challenges for distribution operators. Conventional voltage support devices, such as regulators and capacitors, lack the dynamic capability required to address these challenges. Reconductoring large sections of circuits improves voltage stability but requires substantial resources and may be cost prohibitive.
A new distribution class STATCOM is evaluated in this paper as a non-wires, cost-effective solution for feeder voltage management challenges. The paper addresses practical challenges to integrating high levels of VRE on distribution circuits, including siting concerns and the unfeasible time or cost required for typical system upgrades. The STATCOM’s speed-of-response and maintenance characteristics are compared with conventional regulators and shunt capacitor banks to explain its relative advantage for addressing VRE induced voltage fluctuations. Finally, case studies of observed voltage regulation problems due to VRE are presented to demonstrate the level of mitigation that is possible by adding a distribution STATCOM.
This paper analyses the potential impact of integrating large volumes of variable renewables (RE) on frequency control reserves and presents options for mitigating the associated challenges and costs by enhanced cooperation between the state and regional level. The Southern region is key for the Government of India’s target of installing 175 GW of RE by 2022. With an expected 70 GW of wind and solar power, or about 40% of the national target, up to 38% of local consumption may be supplied by variable RE in the Southern region.
In the first part of the paper, we apply a proven probabilistic method, also used by several European system operators, to quantify the impact of these developments on the future need for secondary and tertiary reserves in the Southern region. By looking at different scenarios and assumptions, we highlight key drivers and risks.
In the second part of the paper, we investigate possible approaches for cost-effectively managing control reserves and real-time system balancing by means of enhanced cooperation between the regional and state load despatch centres. We assess several options for and potentials benefits of improved vertical and horizontal cooperation, including enhanced methods of reserve sharing. We present examples of international best practice and discuss their applicability to the Indian context. We conclude by identifying the most promising options, which appear worth being further discussing by relevant stakeholders in the Southern region.
The high wind energy potential sites are increasingly remote from the load centers which create problems in integrating wind power plants into power grids. One of the major issues is the short-circuit ratio (SSR) at the point of common coupling. A lower short-circuit ratio will lead to a weaker grid which in turn creates power system stability problems. The definition of a weak grid depends on short-circuit ratio values. In New Zealand, it is often noted that the definition of a weak grid, based on SSR, is different from that of standard values (of SSR) due to several reasons.
New Zealand’s grid is long and slender with arguably major generation at one end and load centers at the other side. Close to 80% of daily consumption of electricity is generated from renewables with 5-8% contributed by Wind generation. Wind farm locations in New Zealand share the same difficulties as shared by many nations in terms of remote locations, far away from load centers and wind variability. However, New Zealand wind farm capacity factor is close to 45% and maximum capacity of around 400 hours a year. Over 20 new wind farms have been consented for future with capacity close to 3GW.
This work shares our experience in connecting future wind farms to New Zealand grid and their effect on the weak grid concept. We will discuss the reasons for our definition of short-circuit ratio in New Zealand scenario and, in support, share some results of our simulations.
India has embarked on an ambitious journey for 175 GW of renewable capacity by 2022. The high variability and unpredictability from renewable calls for an efficient and economical operation to maintain grid stability. Energy storage can play an important role in addressing these challenges by meeting peak requirements, providing ramping, shifting and smoothening renewable output, reducing deviation penalties, relieving congestion and providing ancillary services. Storage is still at a nascent stage of evolution, and to ensure well directed investment in this area, it is important to adopt business model that promotes maximum system benefit.
Broadly there are three types of business models based on ownership, application, revenue stream and contract type: generation-coupled, transmission-coupled, and merchant-coupled storage asset. For a generation-coupled asset, ownership and dispatch is controlled by generators and the revenue earned is variable subject to volume-risk (units generated/supplied). A transmission-coupled asset is operated by the system operator providing generation, transmission, distribution, and merchant services based on fixed-annuity agreements. A merchant-coupled asset is owned, operated and dispatched by independent storage providers to participate in energy arbitrage, capacity and ancillary services where such markets exist. Such markets have uncertainty in revenue stream and offtake risk, thus making asset bankability low. Considering experiences from around the world and learnings captured in other papers, this paper proposes a hybrid business model that maximizes system benefit while minimizing project financing costs. In the new model:
1.Storage is deployed as a transmission asset where ownership lies with an independent storage provider, and projects are awarded on an availability-based, fixed-annuity tolling-model, through competitive bidding processes thus minimizing both cost and risk.
2.Asset dispatch is controlled by system operator assuring greatest optimization across multiple value streams. This improves the value created to be 2x-3x over the most lucrative individual use case.
3. Revenue security is ensured by a tolling agreement as this enables the independent storage provider to borrow funds for the longest repayment period at lowest cost. This reduces the required debt service coverage ratio (DSCR) thus reducing the weighted average cost of capital and hence the cost to end-user.
4. As markets for frequency regulation, capacity & energy arbitrage matures and participants develop confidence in operating in these markets, the business model can evolve to include merchant revenues which in turn will reduce the amount of fixed, tolling-annuity required for availability during a pre-specified period.
Finally, the models for utility scale storage are still evolving across the world with each having its pros & cons, and same has been illustrated by taking a sample business case for a renewable rich state in India.
A grid code is a technical specification which defines the requirements to be met by stations, or plants connected to a public electric network. It is intended to ensure safe, secure, economic and proper functioning of the electric power system. The Indian Electricity Grid Code (IEGC) lays down the rules, guidelines and standards to be followed by the various agencies and participants in their different tasks around the electric system. Those tasks can be to plan, to develop, to maintain and to operate the power system or the power plant, in the most efficient, reliable, economic and secure manner, while facilitating healthy competition in the generation and supply of electricity. This paper summarizes the testing and certification procedure for the Indian grid code requirements .
Increasing penetration of uncertain and intermittent renewable energy sources (solar, wind) can cause various problems in grid such as dynamic frequency, voltage fluctuations, and demand-supply imbalance. In countries such as India, where has an ambitious target of adding 175GW RE generation to the grid by 2022, may bring more challenges to the grid operators for sustainable and reliable grid operations. However, a fast responding storage device such as Battery Energy Storage System (BESS) could be used to mitigate these problems in real time operation of power system by providing various grid applications including Frequency Regulation, Energy time shift and RE firming etc. But, the regulations for providing ancillary services have not yet been matured across the globe especially in large power grid network countries like India. This paper discuss about various ancillary services provided by the BESS with different battery technologies. Real time implementation of Li-ion, Advanced Lead Acid and Flow battery systems of 1.25MW capacity by POWERGRID has been considered for this study. The study would also provide insights on regulatory and commercial framework to be adopted by Regulators in allowing large RE integration in Indian grid scenarios.
Integration of Distributed generation (DG) in active grid depends on the grid parameters viz. strength of the network, voltage etc. Network voltage is one of the limitations for penetration of Renewable Energy (RE) based DG into the active power grid. Solar Photovoltaic power generation is a key source of Renewable Energy Sources (RES), which is integrated through the highly efficient and multi-functional inverters. Capability of Solar Inverters (SI) can be utilized to provide the voltage support during critical system need on a 24/7 basis. During night, entire inverter capacity can be used for reactive power support. During the critical voltage condition in the daytime, SI capacity remaining after real power generation can be utilized to improve the voltage stability of the system without any RE curtailment. This paper presents a potential reactive power control schemes for SI, considering enhanced utilization of the inverter reactive power capability to enhance the voltage regulation at the PCC under the physical limitation of the inverter. The Solar Inverter Control (SIC) schemes are incorporated in the optimal power flow (OPF), and formulated as an optimization problem, where, the inverter control schemes are applied to maximize the total distributed generation (DG) penetration and enhance the distribution/transmission network utilization in a typical power grid. Various case studies are presented and compared to evaluate the performance. The results show that the proposed reactive power control scheme can significantly increase the wind penetration levels up to 81% depending of the network constraints and integrated RES.
The hybrid systems consist of one or more renewable energy sources (RES) along with battery energy storage (BES) system satisfying the power demand of the consumers. A generic framework is presented to evaluate the performance of a standalone PV-wind-BES hybrid power system using physics-based battery models. It comprises of PV panels, Maximum Power Point Tracking controller, wind turbine, power electronics, and lithium-ion batteries (LiBs). The dynamic behaviour of LiBs is simulated using physics-based battery models. These models explicitly represent the transport and kinetic processes that take place in the LiBs which help in understanding their operations and achieving better predictions of their performance. The framework for a standalone PV-wind-BES hybrid system is implemented in a MATLAB Simulink environment. A case study is provided using data from a remote residential area in India which would consider variability in load and generation to demonstrate the effectiveness of the proposed framework. The physics-based battery models can be beneficial to analyse the thermal effect and capacity fade to make the best use of the BES system in hybrid power systems.
The Indian electricity sector is expected to undergo significant transition in the coming years, as the share of variable renewables (VRE) increases. This coupled with an annual increase in peak demand could put significant stress on the distribution network operation.
Battery energy storage systems could play a significant role in the distribution network for applications such as voltage regulation, peak shaving and help distribution utilities saving on DSM penalties. With high summer peaks, distribution networks with high penetration of solar rooftop PV systems (SRPV) tend to have a low load factor. So in such distribution feeders, the benefits of load reduction through SRPV, and loading on distribution system components, especially transformers, would not reduce the augmentation/replacement costs on these components. There are certain factors which affect the health/life of distribution transformers (DTs) i.e. (1) Overloading (2) Non-linear load operation (3) Poor maintenance (4) Lightening surge etc. The DT failure rate in India is around 12 to 15 %, overloading is one of the major causes for failure of transformer in urban areas where the population growth is high. The overloading of DT can be prevented by deployment of BESS at distribution downstream while preventing distribution transformer augmentation.
This study tries to access the need for BESS at the distribution level to defer investments on distribution transformer augmentation, reduce DT Failure while increasing the life of the distribution transformer. This application along with energy arbitrate could make viable, BESS at the distribution level. Development and lab testing of control logic for the battery monitoring system along with detailed cost benefit analysis under various scenarios will be undertaken under this study.
Quite notably, over the years, the Distributed Generation (DG) concept has evolved and the role of Renewable Energy (RE) has become increasingly important in shaping the developments. In the form of Distributed Energy Resources (DERs), RE sources also help in reducing burden on the utility by providing an alternative source which is most relevant for a distribution network. With increasing penetration of DERs at the distribution-level, electricity distribution is rapidly transforming into a two-way business where consumers (as prosumers) are selling power back to the utility. All such interactions can be streamlined in the form of Peer to Peer (P2P) trading of energy and a decentralized network between “peers” participating in a local energy market can be created thus transforming into a virtual power plant. If used properly, DERs at the distribution-end can not only reduce losses but can also help the utilities in managing demand more efficiently by engaging people who own these generating assets. Blockchain serves the P2P framework well, creating an efficient platform for energy trading between peers without any requirement of an intermediary. This paper presents a review of the existing major projects on P2P trading using DERs. The aim of this paper is to report different price bidding strategies and auction mechanisms employed to create a win-win approach for both prosumers and consumers. Societal aspects and institutional development required for using Blockchain for P2P trading have also been discussed. In the end, a prototype model for P2P trading of rooftop solar energy, developed by the authors, is introduced.
The Indian power sector is dominated by coal which accounts for 74 percent of the electricity generated. Due to the must run nature of renewables the plant load factor of thermal plants is currently 56%. In this study, we analyze the trade-offs and synergies in cost and emission minimizing power sector operating strategies for the Indian power sector in 2022.
An optimization model is created in TIMES framework with 2018 power sector inventory which includes 620 coal, 239 gas, 22 nuclear and 686 hydro units and capacity addition targets for 2022 (inclusive of 100GW solar and 60GW wind). The power plant units are represented with techno-economic and operational characteristics like availability factors, heat rates, emission factors, ramp rates, minimum generation levels and part load efficiency. The solar and wind capacity is modeled regionwise while thermal power plants have unit-wise representation.
The model also represents the minimum guaranteed offtake for each power plant unit towards Discoms. The model is bottom up, linear programming with unit commitment and dispatch features and minimizes the total cost of electricity production for 2022. We analyze two demand scenarios with 6 and 7 % GDP growth rates till 2022. The cost and emission minimizing operating strategies are compared in terms of emissions, power plant operations, regional distribution, cost of carbon abatement and stranded assets.
We observe that emissions can be reduced by 16-23 percent in the emission minimizing strategy with 36-39 % increase in the cost of electricity. The cost of electricity from coal thermal portfolio also increases by 71-79% in the emission minimizing scenarios. This higher cost of electricity is attributed to higher utilization of new coal thermal power plants and capacity charges from older power plants tied under minimum offtake guarantee. The cost of operations from coal and gas thermal plants increases by 63-56% under minimizing strategy. Nearly 82-84% of the coal thermal capacity tied under power purchase agreements remain unutilized in emission minimizing operations.
The carbon price for emission minimizing scenarios is in the range of 222-229 US$/tonne CO which is significantly higher than all developed countries since it also internalizes cost of stranded assets. This puts a cost burden of additional 511 bn INR on the Indian power sector. This framework can be useful for all countries in analyzing power plant operating strategies and the costs of low carbon transitions
• Increase the flexibility and capacity of the existing power grid.
• Increase network flexibility for grid users at optimised OPEX, which allows for a larger share of RES and increased security of supply.
• Manage congestion within the grid without affecting system reliability.
• Defer CAPEX to build new lines by harnessing the hidden capacities of the existing system.
The integration of intrinsically variable R.E generations shall bring unpredictability in the form of sizeable fluctuations in power flows in transmission networks. It shall also further increase the need for grid reinforcement to guarantee security of supply. The power flows vary with time, seasonal variations as well as daily variations. The network additions to cater these power flows cannot be an economical solution always. Advanced transmission technologies must be tested, and the management of existing infrastructure must be improved. The new technologies like Dynamic line ratings and modular power flow control devices are being tested, implemented and are being successful in their operations in many parts of the world. This paper focus on the idea of integration of both Dynamic line rating and Power Flow controllers to enhance the flexibility of existing transmission infrastructure.
In the Nationally Determined Contributions (NDC) as per the Paris Accord on Climate Change, India made a pledge that by 2030, 40% of our installed power generation capacity shall be based on renewables and the emissions intensity of its GDP reduced by 33 to 35 percent by 2030 from the 2005 level. Keeping this in view and also keeping in view of commitment to a healthy planet, the Renewable Energy (RE) capacity of 175 GW targeted to be installed by 2022 in India. The substantial higher capacity target will ensure greater energy security, improved energy access, and enhanced employment opportunities. With the accomplishment of these ambitious targets, India will become one of the largest Green Energy producers in the world, surpassing several developed countries.
The capacity of around 82 GW has already been installed form different sources of renewable energy. The cost of solar and wind power generation has also declined significantly and for new projects, depending upon the location, the cost ranges between Rs. 2.44 per unit and Rs.2.85 per unit of power produced. On a life-cycle basis, the delivered cost of solar and wind power (even after including the normative transmission charges of Rs 1 per unit of power), has become cheaper than the marginal cost of power from thermal power plants. The demand forecast suggests that by the year 2030 a solar and wind power capacity of 500 GW will be required. Now, renewable energy is not only a matter of commitment and faith but also has emerged as a cost-competitive option for meeting the electricity requirement.
With this background, the present paper reviews the current status and role of Solar Parks in the growth of the National Solar Mission & renewable energy sector, Initiatives and especially the development of solar parks in India which are the key factor to set up a new era of the solar industry in India. Further, the challenge faced by Solar Project Developers (SPDs) & Solar Power Park Developers (SPPDs) has been discussed in this paper.
This includes aspects of the move from Solar Parks to RE Parks to reduce the effect of critical elements of land and transmission system for sustainable growth of RE in India. Further, a case study of operational 1000 MW Kurnool Solar Park is also included in the paper to analyze the variation in generation of energy, system voltage, and the frequency as a reference.
Keywords-National Solar Mission (NSM); Solar Park; Transmission System; Renewable Energy;