The Pinnapuram integrated renewable energy with storage project (IRESP) is a 3.6GW hybrid renewable energy project comprising a 2GW photovoltaic (PV) solar farm, a 400MW wind farm, and a 1.2GW pumped storage hydroelectric facility proposed to be developed in the Pinnapuram village, in the Kurnool district of Andhra Pradesh, India.

The hybrid solar-wind-pumped storage project is being developed by Greenko, a renewable independent power producer (IPP) based in India.

A Memorandum of Understanding (MoU) was signed between Greenko and the Government of Andhra Pradesh in February 2018, while a pre-feasibility study for the project was completed in the same year.

The detailed design and engineering contract for the pumped-storage component of the project was awarded in March 2020. The Pinnapuram pumped-storage hydropower project is estimated to cost approximately £600m ($725m).

The Pinnapuram IRESP is expected to be India’s first and one of the world’s biggest such facilities to supply schedule power on demand (SPOD). Designed for both peak load and baseload operations, the integrated facility will be capable of generating up to seven billion units of electricity a year.

Pinnapuram pumped storage power plant make-up 

The Pinnapuram pumped storage hydroelectric facility will comprise a lower reservoir, an upper reservoir, and a subsurface powerhouse measuring approximately 240m-long, 24m-wide, and 58m-high.

The powerhouse will be connected with six tunnels and penstock pipes and will be equipped with eight Francis type, vertical shaft, variable speed, reversible pump-turbine units. The turbines will operate at a rated head of 134m.

Each of the penstocks will be 760m-long with a 7m-diametre. One of the six penstocks will be bifurcated into two penstocks.

The facility will also house a 420kV gas-insulated switchgear (GIS) along with step-up transformers near the powerhouse.

Pinnapuram pumped storage facility reservoir details

The lower reservoir for the Pinnapuram pumped storage hydroelectric facility will be the existing Gorakallu (Narasimharaya Sagar) reservoir which is located near Gorakallu village in the Nandyal  Mandal,  approximately  80Km away from  Kurnool.

The upper reservoir for the project will be created by constructing a 49m-high dam near Pinnapuram. The upper reservoir will be created across Muni Madugu and will have a catchment area of approximately 9.45km2.

The live storage capacities of the lower and upper reservoir will be 12.44 thousand million cubic feet (TMC) and 1TMC respectively.

The pumped storage facility will utilise approximately 1,140MW of electricity to pump 1TMC of water from the lower reservoir to the upper reservoir for storage in 9.2 hours.

While operating in turbine mode, the facility will generate up to 1GWh of electricity by utilising 862.5 cubic metres per second (Cumec) of the design discharge of stored water from the upper reservoir. 

Power evacuation

The Pinnapuram integrated renewable energy facility will have a central pooling station to gather electricity from each of the three components of the project.

The electricity from the Pinnapuram IRESP common pooling station will be evacuated into the national grid through connection to the Power Grid Corporation of India’s (PGCIL) 765/400/220kV substation near Orvakallu. 

Contractors involved

AFRY India, a subsidiary of Swedish engineering and consulting company AFRY, was awarded a £2.2m ($2.5m) contract by Greenko Energy Projects for the detailed design and engineering services for the Pinnapuram pumped storage hydropower facility in March 2020.

India-based Aarvee Associates Architects Engineers and Consultants was engaged to prepare the pre-feasibility study report for the Pinnapuram IRESP.