Ember Says Battery Subsidy Could Add 15–25 GWh to India's Rooftops

• Ember says a battery subsidy under India's PM Surya Ghar rooftop scheme could add 15–25 GWh of home storage for about INR 280 billion.
• A 5-kWh battery cuts a home's daytime solar exports by 85–90% but stretches payback from 3.3 years to about 9 years.
• The scheme passed 5 million households in August; the minister expects 7.5 million by December 2026.

India could add 15–25 GWh of home batteries if its PM Surya Ghar rooftop solar program also funded storage, Ember said on Oct. 22. In its report, the energy think tank put the cost at about INR 280 billion ($2.9 billion at the RBI's Oct. 23 reference rate, a list.solar calculation).

The estimate covers 5 million households, half the program's 10-million-home target, in its next funding tranche.

The issue is timing. Households export much of their midday output and draw power back after sunset. Net metering credits the two units one-for-one. Yet day-ahead power prices drop to a floor of about INR 1.56 ($0.016) per kWh in solar hours. In the evening they climb about six-fold to the INR 10 ($0.11) cap, Ember said.

Ember modelled a 3-kW rooftop solar system that generates about 350 kWh a month. It costs INR 165,000 ($1,740), or INR 87,000 ($920) after the scheme's grant, and pays back in 3.3 years. A 5-kWh battery lifts the cost to INR 227,000 ($2,390) and cuts daytime exports by 85–90%. Payback stretches to about 9 years. A 50% subsidy on the battery would bring it to 6.3 years.

India's rooftop battery case in numbers

• 30.7 GW of India's 164.6 GW of solar capacity sat on rooftops in July 2026, about 19%.
• 14.9 GW of residential rooftop solar was installed under PM Surya Ghar across 5 million homes by July.
• 3–5 kWh of storage per home is implied by 15–25 GWh across 5 million households (list.solar calculation).
• INR 56,000 ($590) of support per household under Ember's budget (list.solar calculation).
• INR 280.24 billion ($2.95 billion) in rooftop subsidies had reached households by Aug. 4, the Ministry of New and Renewable Energy said, almost exactly Ember's battery budget.

The program started in February 2024 with an outlay of INR 750 billion ($7.9 billion). In June, minister Pralhad Joshi said it would add battery storage as costs decline, according to a ministry release.

"With more than 5 million households already adopting rooftop solar under PM Surya Ghar, we should be building storage alongside that capacity, not years later," Ember energy analyst Ruchita Shah said in the report.

Ember also suggested that states which top up the central grant, such as Tamil Nadu and Bihar, steer that money toward batteries. Joshi expects the program to reach 7.5 million households by December 2026.