India’s clean energy transition is largely driven by the ambitious target of installing 450 gigawatts (GW) of renewable energy (RE) by 2030. While such huge RE deployment can pose several operational and technical challenges for the grid, energy storage can mitigate them.
Among the various energy storage technologies, pumped-hydro storage (PHS) and battery storage are emerging as the front-runners. PHS, the oldest and most mature large-scale storage technology, accounts for 96 per cent of installed global energy storage capacity. Around 169 GW of pumped storage capacity is installed worldwide, with China leading with 32.1 GW, followed by Japan with 28.5 GW, and United States with 24.2 GW.
PHS is a type of hydroelectric energy storage which uses a two-reservoir system (upper and lower) to store energy and generate electricity. It is of two types: ‘open loop’, which has an associated natural-water source (like a river) for one or both the reservoirs; and ‘closed loop’ (or off-river PHS), which does not have a connected natural-water source and the same water is cycled between the two reservoirs for pumping and generation.
Unlike battery storage technology that uses expensive and critical materials such as lithium, nickel, and cobalt (lithium-based), or polluting materials such as lead (lead acid)