Flexibility requirement for large-scale renewable energy integration in Indian power system: Technology, policy and modeling options

Abstract Reliable and stable power system operation requires flexibility, in addition to capacity adequacy. Traditional system components either have limited flexibility to suppress extensive system variation, or their role is limited due to lack of proper regulatory provisions and inefficient market design. Large-scale integration of renewable energy (RE) resources (e.g., solar, wind) imposes additional variability and uncertainty to the existing system and thus enhances flexibility need. There are various solutions to the problem. Revamping system operation protocol with existing resources, retrofitting current power-generating assets, network expansion, etc. can provide flexible service. Investing in a new type of resources like energy storage and demand-side response (DSR) however, needs aggressive policy interventions and market mechanisms. Identifying suitable flexible resources and designing appropriate policy structures require long-term system planning. Traditional methods in this regard need to evolve to consider the operation-scale impact of large-scale RE integration at the planning stage such that long-term carbon emission reduction targets can be met. The approach towards transitioning into a flexible energy system can differ according to its present status. This paper focuses on the Indian power sector’s perspective, which has ambitious RE integration goals. With a fast-evolving system configuration, flexibility related challenges are high in India due to weak infrastructure, inefficient regulatory policies, and aggregated planning methods. This article presents the current status of the Indian power system detailing existing technology types, regulatory norms, and future targets. It further details a comprehensive review of relevant technical options, market mechanisms and planning approaches for transitioning into a flexible power system for India. Comparative analysis with international experiences highlights the need for a major paradigm shift. A short-term transition towards becoming a flexible system can focus on developing adequate transmission infrastructure, exploit available pumped hydro storage potential and retrofitting existing coal-fired power plants. On longer-term, innovating market mechanisms and regulatory changes should drive investment into emerging flexible resources like DSR, storage, etc. Planning for this transition should be designed using improved modeling and planning approaches which should focus on the interlinking of different sector-specific models.