Experience on Ancillary Service in Indian Electricity Markets-Urgent Need of an Hour for the States Trivedi J.D., Darji C.C. Gujarat Energy Transmission Corporation Limited (GETCO) Online published on 6 February, 2020. Abstract This paper discusses the experience on Ancillary Services in Indian Electricity Markets so far and its urgent need for the States. The authors present the evolution, chronological developments, implementation and benefits of Ancillary Services. The salient features of various types of Ancillary services as introduced by Central Electricity Regulatory Commission along with the role and responsibility of various stake holders and nodal agencies are presented. Ancillary Services are support services which are required for improving and enhancing the reliability and security of the electrical power system. Authors present that with the continuous increase in the RE integration with the grid, ancillary services become more and more important. Presently, Ancillary services are implemented at central level (i.e., for the regional entities) since April 2016. All the Generators, that are Regional Entities, and whose tariff for the full capacity is determined or adopted by the CERC have been mandated to provide Ancillary Services as Reserve Regulation Ancillary Service (RRAS) Providers. RRAS predominantly utilizes the URS of thermal power stations which have ‘ramping limitations’ and as such there is a need for a fast response ancillary service. Hydro stations can respond very quickly and much faster than thermal/gas stations. Accordingly, CERC has introduced (order dated 16.07.2018) the concept of Fast Responding Ancillary Service (FRAS) by utilizing storage/pondage based hydro generating stations primarily for regulation service. As on date, PAN India RE installed capacity is around 75 GW out of total target of 175 GW by 2022. Further, the quantum of ISTS connected RE installed capacity is about 2 GW. In other words, ratio of RE installed capacity connected to ISTS to State transmission system is 2: 98. It reveals that the States are the main and direct victim of RE injection variability and intermittency since the beginning. Hence, authors emphasis the Ancillary services as an urgent need of an hour for the States. State system operator particularly having high RE penetration has many issues viz. absence of intrastate RE framework, ‘Must Run’ status of RE, less availability of cheaper gas in turn lesser availability of ‘on bar’ gas generating stations, constraints in operation of hydro generation including constraints of pump mode operation, adherence of stringent provisions of CERC DSM 4th amendment, tripping/outage of large size generating unit, operation of merchant power plants, non-availability of adequate balancing mechanism etc. In order to address the above issues, authors suggest to evolve State regulatory framework equally along with the central sector. Introduction of strong framework of Ancillary services for the States would empower the State system operator and that will definitely help to improve the overall grid reliability and security of the nation as a whole. Authors have also elaborated examples of real time difficulties faced by the system operator and its likely solutions. Looking to the need of time, Authors strongly suggest to introduce various products like AsPO (ancillary services purchase obligation-similar to RPO), AsPO should also be categorically defined (hydro, battery, CSP etc.), mandatory provisions/incentive for pump mode operation, mandatory installation of balancing mechanism for upcoming RE, real time market for ancillary services etc. Top Keywords Ancillary Services, RRAS, FRAS, DSM, Large Scale RE integration, URS. Top |