Rooftop solar with storage: Are consumers ready?

Rooftop solar (RTS) has gained significant momentum in India following the launch of the PM Surya Ghar Muft Bijli Yojana (PM Yojana).

- SHARATH RAO & RAHUL TONGIA

Rooftop solar (RTS) has gained significant momentum in India following the launch of the PM Surya Ghar Muft Bijli Yojana (PM Yojana). Before the scheme, cumulative RTS installations stood at 11.07 GW, but in the past year alone, 5.21 GW has been added, predominantly in the residential sector.

However, as solar penetration increases, concerns about grid stability, reliability, intermittency, and local over-injection are growing. In response, the Ministry of Power issued an advisory urging distribution companies (discoms) to consider mandating two-hour storage with RTS. Although later clarified by the Central Electricity Authority (CEA) as "guidance", this could become a mandatory requirement in the future.

Solar's daytime-only output is well-known, and using storage to get power during other periods, especially the evening peak, seems like an obvious solution. However, cost remains a significant hurdle. While batteries are becoming cheaper, they are still expensive. This issue is further compounded by the fact that under current "net-metering" frameworks, households can treat the grid as a virtual battery, allowing them to draw their mid-day exported power back at night from the discom at nearly zero additional cost.