By Akhil Aggarwal, Vice President, Greenko Group
India’s rapidly growing renewable energy capacity is transforming the electricity mix. As the share of intermittent renewables continues to rise, the need for despatchable clean energy becomes important. In this context, pumped storage projects (PSPs) are among the front runners as a scalable and bankable solution.
Against this backdrop, Greenko’s Integrated Renewable Energy Project (IREP) at Pinnapuram, Andhra Pradesh, stands as an example of how large-scale renewable-energy-backed energy storage infrastructure can address the intermittency challenge. The project combines a 1,680 MW closed-loop pumped storage system with 1,500 MW of co-located solar PV capacity to deliver firm, despatchable and schedulable renewable power to the grid. It forms a key part of Greenko’s broader strategy to develop an over 100 GWh energy storage cloud, and serves as a model for next-generation renewable infrastructure.
Key project details
The IREP is designed as a closed-loop, off-stream pumped storage system combined with a large-scale solar PV plant. Strategically located in Kurnool district, the project features a total energy storage capacity of 11,250 MWh. The pumped storage component comprises eight fixed-speed, reverse-Francis turbines, with six units of 240 MW and two units of 120 MW delivering a cumulative discharge capacity of 1,680 MW. The upper and lower reservoirs have been engineered with nearly symmetrical live storage capacities of 1.346 TMC and 1.305 TMC, respectively. The system has been designed for dual-mode operation, enabling it to pump water for 7.7 hours and generate electricity for 6.7 hours per cycle. The reversible turbine-enabled pumped generator configuration supported by penstocks and geomembrane faced rockfill dams, to enable rapid transition between pumping and generating modes while ensuring operational efficiency. As of July 2025, five units have been commissioned, and trial operations are planned for the remaining three units. Both the solar and storage components are connected to the national transmission network through an interstate transmission system (ISTS) substation rated at 765/400 kV, thereby ensuring grid-scale integration and scalability.
Policy and regulatory support
Under the Ministry of Power’s guidelines, PSPs awarded before June 30, 2025 are exempt from ISTS charges for a period of 25 years, with a phased reintroduction of charges beginning July 2025. Additionally, electricity duty, cess and cross-subsidy surcharges on energy consumed for pumping have been waived for 10 years, while water cess is not applicable.
The central government has also allocated financial assistance in tiers according to project size, with Rs 10 million per MW for projects up to 200 MW and an additional Rs 7.5 million per MW for capacity above 200 MW. In exceptional cases, support may rise to Rs 15 million per MW.
In order to improve financing of projects, central institutions such as the Power Finance Corporation, REC Limited and IREDA have allocated long-term loans of 20–25 years while treating PSPs at par with other renewable energy projects.
Market structure
Greenko has secured long-term contracts for approximately 1,000 MW of capacity from the Pinnapuram PSP, with offtakers including the Solar Energy Corporation of India and ArcelorMittal Nippon Steel. The remaining capacity is being utilised for merchant sale and captive applications, including upcoming green hydrogen and ammonia production facilities. The offtake and procurement landscape for PSPs is undergoing a structured evolution.
Challenges and learnings
Despite growing policy support, the development and scaling of PSPs continue to face key challenges across market readiness, regulatory adaptation and institutional capacity.
On the market side, investors’ confidence and offtakers’ acceptance of PSP tariffs should transition from tentative to affirmative. On the regulatory front, while progress has been made, further clarity is required on aspects such as deviation settlement, procurement structures and market participation mechanisms.
Outlook
As per the Central Electricity Authority, India’s pumped storage capacity is projected to expand from the current 4.7 GW to 90 GW by 2047. As utility procurement transitions from round-the-clock power to peak-focused tenders, it is expected that renewable-energy-integrated and standalone pumped storage projects will emerge.
In this context, Greenko’s IREP combines technical complexity with commercial innovation by demonstrating how pumped storage can be effectively integrated with solar generation to deliver firm, despatchable renewable energy.
