Maharashtra RE & Storage Policy 2025–36: The 100 kW Solar Storage Rule Explained

Since 1 April 2026, Maharashtra has quietly rewritten the economics of C&I solar. The state's RE & Storage Policy 2025–36 makes it the first in India to hard-wire batteries into solar approvals: every new solar project above 100 kW now needs energy storage just to get grid connectivity.

If you sell, buy or build solar in Maharashtra, solar alone will no longer get you a connection. The rule comes down to three numbers:

• 100 kW: the threshold. Not a megawatt.
• 50%: minimum storage power, for 2 hours.
• 0: exemptions once you cross the threshold.

The storage ratio and duration: half the power, two hours now, four from FY 2030-31

The battery's power rating must be at least 50% of your solar or wind capacity, and it must deliver that power continuously for a minimum of 2 hours. For example, connecting 1 MW of solar requires a BESS power rating of at least 500 kW, and 500 kW × 2 hr = 1,000 kWh. Power sets the ratio; duration sets the energy you buy.

The battery is rated by how long it can discharge at rated capacity, and that duration steps up:

• From 1 April 2026: 2 hours minimum discharge at rated capacity, enough to cover the evening peak.
• From FY 2030-31: 4 hours for projects commissioned from that year. Build for 2 hours and you may be retrofitting in four years.

Worth knowing: going to 4 hours today can unlock a 10-year electricity-duty holiday on captive projects.

Who it covers: this is not a rooftop-only rule

Above 100 kW, the rule lands on you whichever route you take to the grid:

• HT-Industrial above 100 kW: new plants in MIDC estates such as Chakan, Waluj, Butibori and Sinnar.
• HT-Commercial above 100 kW: malls, hospitals, hotels, IT parks and data centres.
• Rooftop captive above 100 kW: behind-the-meter self-consumption, not just net metering.
• Group captive and open access above 100 kW: solar and wind procured off-site through open access too.

100 kW is the line, not a megawatt. A modest C&I rooftop already crosses it.

The consequence: you cannot add the battery later

Connectivity itself is gated on storage: no BESS, no connection. The cut-off is 1 April 2026 for applications for new connectivity above 100 kW.

• Solar + compliant storage: connectivity granted, and the project moves.
• Solar only: no connectivity, and the project does not energise.

Existing plants keep their connection, but the revised banking and ToD rules still cut their returns. A solar-only quote signed in Maharashtra today is a quote for a project that cannot energise.

The way through is to know your number before you quote. Three questions decide whether the rule is yours to solve: Is it a new solar project? Is it above 100 kW? Is it in Maharashtra? Three yeses mean you should model the minimum compliant BESS size, duration and payback before quoting, and check that your EPC is already quoting the battery. Ingro Sims does this at sims.ingroenergy.com, free for your first five projects.