India will require 888 GWh of energy storage system capacity by 2035-36, up from 1 GWh currently, according to an industry report released on Wednesday. The report highlighted how energy storage is now the key pillar in strengthening grid reliability and enabling the country's renewable energy ambitions, a statement said. India will require 888 GWh of energy storage system (ESS) capacity by 2035-36, from the existing 1 GWh scale, according to the 'India BESS Market Review' released by India Energy Storage Alliance (IESA) and Customized Energy Solutions (CES) at India Energy Storage Week (IESW) here on Wednesday.