A step towards grid stability

How pumped storage is emerging as a reliable option to store the electricity generated from renewable sources of energy

- ANAND TANDON

India had committed scaling up renewable capacity to 175 GW by 2022- of this, 100 GW was to come from solar and 60 GW from wind. These figures have not been achieved. As per Central Electricity Authority's (CEA) data for June 2022, the total renewable installed capacity is about 161 GW, with the solar and wind capacities at 57.7 and 40.8 GW, respectively.

India is further committed to raising renewable generation to 450 GW by 2030. India's power grid is one of the largest integrated grids in the world. Variability and unpredictability of generation introduced by renewables makes grid stability a matter of concern. Wind blows strongly at night when demand is low. Solar peaks do not match peak power demand. Without the match peak power demand. Without the capability of storing power generated by renewables, steady generators like thermal power plants must backdown when renewable generation is high. This variability is easy for gas-powered plants but reduces the operational efficiency of coal-powered plants. India has limited availability of gas and what is available is used for fertilisers, mobility and domestic uses. India's coal-powered generating capacity has limited flexibility to absorb large intermittent production from renewables.

Power prices are also based on time of day, with peaking power being charged more. This adds complexity when power banked' in the grid in off-peak hours is sought to be drawn in peak time. This complexity is a key reason why power-purchase agreements for renewables are slowing down. Gridscale storage is a key requirement.

Grid-scale storage