How did you get that number? Is this just a quip about batteries?

Most of India has a solar capacity factor >0.2 and low seasonality. That means even 5kW peak rooftop panels and a 10 kWh battery will get you over 95% almost always. And panels+labor is so cheap in India, there's really no reason not to just tile the roof in panels.

Things get more difficult in dense cities, if you have multi story apartment blocks going 90+% locally is impossible. But then just transmit power from lower density rooftops, or actual solar farms.

And this already assumes widespread AC (really no way to increase electrification this much and not add AC in that climate).