By S K Soonee, K V S Baba, S C Saxena, K V N Pawan Kumar
Indian power system is progressing on the path to integrate 175 GW renewables by 2022. The target, though a daunting one, seems to be within the realms of reality. Several measures were initiated including, inter-alia, amendments in policies, introduction of Renewable Purchase Obligation (RPO) programs, encouragement of competitive pricing, augmentation and strengthening of power transmission network (Green Energy Corridors), regulatory interventions for a suitable electricity market design, a dozen of dedicated Renewable Energy Management Centres (REMCs) for smart operational management of renewables, synchrophasor technology as an enabler of the transmission smart grid and, last but not the least, promotion of innovation and financial support for sustainable distribution utilities.
At present, India is the third largest economy (in Purchasing Power Parity (PPP) terms) as well as the third largest energy consumer in the world. India is setting the pace in global demand. Energy is at the heart of India’s drive for development and modernization. With 18% of the world’s population, India’s share of energy consumption is only 6 %.
India is bestowed with an estimated renewable energy potential of over 1 TW from commercially exploitable sources, namely wind (about 302 GW, assuming wind generators of 100 m hub-height), small hydro (21 GW), energy from biomass/biogas (25 GW), and solar (750 GW assuming 3% wasteland). Therefore, the Indian energy sector needed a transformational push to transition from a system largely based on fossil fuels, to a cleaner energy one supporting sustainable development.
Renewable capacity has grown at an annual growth rate of 18% over the last few years. At present, renewables contribute around 65 GW out of the nationally installed capacity of 334 GW, thus, representing the second highest contributor to the electric energy portfolio of India after fossil-based generation. National Electricity Plan estimates renewables to contribute about 20% and 24% of the total energy requirement in India by 2021-22 and 2026-27, respectively.
‘Electricity Act, 2003’ and ‘National Electricity Policy, 2005’ provide the necessary legal framework for the development of renewable power capable to interact with the grid. The tariff policy, as revised in January 2016, has several provisions aimed at accelerating deployment of renewable energy in the country, including, among others, provisions for (a) 8% solar RPO by 2022, (b) Renewable Generation Obligation on new coal/lignite based thermal plants, and (c) exemption of renewable energy from inter-state transmission charges. The government has also issued guidelines for the long-term trajectory of RPOs. A high level technical committee, put together by the Ministry of Power of the Government of India, for renewable integration set forth a 15-point Action Plan in April, 2016 for facilitating large scale integration of renewables, in a secure and reliable manner.
‘National Offshore Wind Energy Policy, 2015’ details the guidelines for development of offshore wind energy along the vast coastline of 7,600 km. A plan for 40 GW Solar Parks and Ultra Mega Solar Power Projects has been developed in 2017. This plan ensures the installation of at least 50 solar parks, of 500 MW capacity (or more) each in various parts of the country. The ‘Guidelines on Cross Border Trade of Electricity, 2016’ provide for allowing and enabling renewables in South Asia to access to larger electricity markets.
Several regulatory interventions by Central and State Electricity Regulatory Commissions’ have been made to facilitate renewable integration. Scheduling, Accounting, Metering and Settlement of Transactions in Electricity framework implementation is underway at the intra-state level to introduce and harmonize regulatory framework with regards to renewables. The provisions in Indian Electricity Grid Code were made in 2016 to harness and incentivize flexibility in the conventional generation.
A combination of centralized and decentralized forecasting framework has been mandated, wherein, forecasting is to be done both by the renewable generator & the respective Load Despatch Centre. Unlike conventional generation, deviation charges of renewable generation have been decoupled from the frequency.
The concept of Aggregators, as “Qualified Coordinating Agency”, has been introduced at the intra-state level to facilitate activities relevant to the connectivity, scheduling, communication and commercial settlement for renewables less than 50 MW. Regulatory framework for more opportunities to trade in electricity markets has been provided with 24x7 extended market operation since 2015. A regulatory staff paper on “Introduction of Electricity Storage System in India” has also been issued.
Reserve Regulation Ancillary Services in India have been implemented in April 2016 to support grid reliability. Automatic Generation Control (AGC), previously not employed, has been employed in January 2018 with 5-minute response and associated regulatory framework. The pan-India implementation of AGC is under progress.
REMCs are being established across India at state (7 centres), regional (3 centres) and national (1 centre) levels for real time tracking, forecasting, geo-spatial visualization and information repository for renewables. Green Energy Corridors for transmitting renewable generation through enforced inter-state and intra-state transmission systems are also under progress for about 43 GW of renewables in 8 renewable-energy-rich states.
Synchrophasor technology, with deployment of around 1750 Phasor Measurement Units (PMUs) across India, is being installed to facilitate dynamic state measurement and visualization of Indian power system under Unified Real Time Dynamic State Measurement project. At present, data from over 180 PMUs assist the system operators across pan-India control centres in real-time as well as post-despatch. Control actions based on time synchronized high-resolution synchrophasor signals are an important part of the smart grid. The development of PMU applications, especially for REMCs, is in progress viz. power system state, simulation model validation, incident analysis and inter-area oscillations.
A national study on grid integration of renewables was carried out in June 2017, which concluded that all of the 175 GW of renewables planned to be installed can be integrated smoothly (i.e. minimal curtailment levels). Other studies, examining renewable integration, have also been conducted in the recent past viz. optimization of hydro and gas resources, spinning reserves, deviation settlement mechanism and 5-minute-ahead scheduling & settlement.
Capacity building for all stakeholders is being organized with national and international faculties including National Power Training Institute (NPTI), National Institute of Wind Energy (NIWE), Indian Institute of Technology (IIT), United States Agency for International Development (USAID) and Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ). Specialist-level system operator certification in renewable energy integration has been initiated for pan-India system operators.
In near term, advanced grid reliability services, such as Fast Frequency Regulation, Synthetic Inertia, Reactive Power Support, Black Start etc., which provide financial incentives to the deployment and operation of flexible resources have to be developed. The future energy systems will utilize the power of advanced Information Technology architectures that support the increasing decentralization of the power grids. New and evolving digital technologies such as Artificial Intelligence, Big Data, Blockchain and Cloud Computing would form the backbone of the smart grid in India in the future.
This article was edited by Mehmet Cintuglu.
K.V.S. Baba is currently Chairman & Managing Director at Power System Operation Corporation Ltd (POSOCO). He has experience in power system planning, system operation, system reliability, open access, and renewable integration. He currently represents India on the CIGRE Study Committee C2 on Power System Operation.
Sushil K. Soonee is a founder, current adviser and former CEO at POSOCO. He has worked extensively on integration of grids to form the National Grid of India. He is FIEEE, FNAE, Life FIE(I), Distinguished member CIGRE. .
S.C. Saxena is currently working in market operations at the National Load Dispatch Centre, POSOCO and has experience in electricity markets, system operation, grid integration of renewables, regulatory affairs and SCADA-IT. He is a SMIEEE, member-CIGRE and MIE.
K.V.N Pawan Kumar, IEEE member, is currently working as Deputy Manager in Market Operations Department at NLDC, POSOCO. He has around eight years of experience in policy, regulatory affairs, renewable integration and open access.