Hydropower: Let pump dams fill gaps in India’s clean energy supply

livemint.com:

₹25,000-27,500 crore in pumped-storage hydropower (PSH) dams over the next five odd years, with PSH capacity of 5 gigawatts as its initial goal. Having already invested heavily in wind and solar projects, Adani expects to move fast on this, aiming to scale up its PSH capacity to 25GW eventually. Players like Tata Power, JSW and the state-run NTPC also plan pump dams.

Earlier this year, the Union environment ministry had cleared PSH projects worth over ₹80,000 crore, but Adani’s outlay is now the largest. Its entry will boost the country’s drive for sustainable power generation. What sets PSH units apart is that the power they generate can go by the sum of our needs rather than the vagaries of nature.

This means they can be linked to grids to solve the problem of supply intermittency faced by other sources that do not use fossil fuels. Regular old dams hold water in vast lakes; by opening sluice gates to let it cascade onto watermills that rotate under its force to create electricity, they can vary their output, going full pep to maximum capacity if need be. The same applies to PSH units, which are typically smaller but differ in a significant way.

Their reservoirs, built as usual at some height, are self-fed with water that’s routinely pumped back up after use (using less power of course). Pumps relieve such dams of the need for natural water inflows. A steep hillside, for example, is all they need.

So, while PSH generators are capital intensive, they face fewer limitations of geography than classic river dams built in hilly regions. Spotting the appropriate topography to create a little lake is not short of its own challenges, but water recycling expands the country’s scope for hydropower manifold. Although the basic