As lithium-ion batteries take centre-stage in the global pursuit for efficient energy storage systems, India has quietly readied a plan aimed at creating systems that can store up to 10,000 mw of intermittently-generated renewable power at a fraction of the cost the West will bear.
The about 80,000-crore plan entails setting up hydel pump storage systems in several states over the next five to six years, said SD Dubey, chairman of Central Electricity Authority. He was speaking on the sidelines of an Energy Conclave organized by CII in Kolkata. A pumped storage facility consists of two large water tanks at two levels-one at the base of a hill and the other at the top of the hill. During the day, when solar power is generated, a portion of the power will be used to pump water from the lower tank to the higher one. At night, when solar power isn't available, water from the elevated tank will be released to work a turbine and generate power.
These 'pumped' storage systems can store 1,000 mw or more of power for any duration at a fraction of the cost entailed using lithium-ion batteries. Solar energy can be generated only during the day. If this power is stored in lithium ion batteries and supplied at night, the process will entail an additional cost of 10 per unit - the storage cost. In contrast, pumped storage power will entail an additional cost of 30-40 paise per unit, according to Dubey.
"Cost of setting up such hydel pumped storage systems is anything between 6 crore and 8 crore per megawatt. Cost of setting up solar generating stations is between 5 crore and 6 crore per megawatt. In fact, the Central Electricity Authority has already identified plans of setting up 10,000 mw of pumped storage systems," said Dubey. The country has a potential of setting up 90,000 mw of pumped storage system.
