New Delhi, Aug. 31 -- India's green investment story is a success by several measures. In 2024, 83% of all investment in its power sector went into clean energy, according to the International Energy Agency. Renewable capacity is expanding rapidly and the country is building domestic manufacturing capabilities in batteries and other clean-energy technologies. But the success has hidden a weakness.

India is getting better at financing the deployment of proven green technologies. It is much less adept at financing the technologies it will need for the next stage of its transition to a low-carbon economy.

A solar park can obtain credit because lenders understand the technology, output and revenue model. A new battery chemistry, long-durati...