If you’re planning a rooftop solar or Open Access project above 100 kW in Maharashtra, here’s something to know before you go any further—solar panels alone won’t be enough anymore. A battery now needs to be part of the plan too.

The rule itself isn’t new. The Maharashtra government announced it on 27 March 2026 as part of its Renewable Energy and Energy Storage Policy, effective 1 April 2026 for new projects.

What’s changed more recently is how it’s being applied on the ground. From 1 September 2026, MSEDCL has been factoring this storage requirement into the solar PV application process itself, without a separate circular spelling it out in advance. In practice, this means some applicants have only come across the requirement while registering their project — rather than knowing about it beforehand. If that’s happened to you, this article walks through exactly what’s required and how to plan around it.

So what does the rule actually say?

Strip away the policy language, and it comes down to this: any new solar or renewable project above 100 kW applying for grid connection on or after 1 April 2026 needs a battery alongside it, sized to at least 50% of the solar plant’s capacity.

Take a 200 kW solar plant as an example. You’d need at least a 100 kW battery sitting alongside your panels.

Worth noting: this only applies to new projects. If you already have rooftop solar up and running, you’re not obligated to retrofit a battery, even though the state would like you to. And it’s not just rooftop solar either. Open Access projects going through the transmission network from April 2026 fall under the same rule.

Why bring this in now?

Truthfully, this has been building for a while. Maharashtra’s renewable capacity crossed 31.3 GW by January 2026, with rooftop solar alone past the 5 GW mark. That’s a lot of power flooding into the grid during daylight hours and very little of it available once the sun goes down. Batteries are the state’s way of smoothing that mismatch out, storing the daytime surplus so it can be drawn on later when demand is still high, but generation has dropped off.

Why it actually matters to your business

Most businesses that go solar factories, warehouses, hospitals, hotels, offices aren’t running only in daylight hours. Solar helps during the day, but the moment the sun sets, you’re back on the grid, paying full price again.

A battery changes that equation. It banks the extra solar you generate in the afternoon and lets you draw on it in the evening instead of buying grid power at that hour. Whether that translates into meaningful savings for you specifically depends on a few things your load pattern, your tariff structure, how much solar you’re actually generating, and whether the battery is sized correctly for your use case. There’s no one-size-fits-all number here, which is exactly why a proper assessment matters more than a rule-of-thumb estimate.

Planning a solar project just got a layer more complicated

It used to be fairly straightforward figure out your rooftop space, pick a panel capacity, done. Now there’s more to juggle.

Start with your actual consumption, not your rooftop space, when deciding how much solar to install — oversizing or undersizing either way eats into your returns. Once that’s settled, the battery isn’t sized off your annual generation figures; it’s tied directly to your solar capacity and the mandated backup window, so getting that number right matters more than people initially assume. Then there’s everything the battery brings with it inverters, safety systems, transformers, metering, and enough ventilation and fire-safety planning to keep the whole setup compliant and safe. And finally, before you commit to any of it, check your grid connectivity requirements, particularly if you’re routing through Open Access, since this storage mandate is tied directly to your transmission approval.

Does this push up your project cost? Yes but that’s not the whole story

There’s no getting around it: adding a battery raises your upfront investment compared to a solar-only setup. But treating that purely as an added expense misses the point.

A properly sized battery lets you use more of the solar power you’re already generating, shifts your consumption away from the costliest grid hours, and gives you a more dependable supply overall. And battery prices have been on a downward trend as the technology matures, so the economics here aren’t static — they’re improving.

The more useful question isn’t “how much extra will this cost me,” but “how much value will this battery actually generate for my business.” And that answer only comes from looking closely at your consumption pattern, your tariff, and your operating hours not from a generic estimate.

A quick checklist before you move forward

• Pull together at least 12 months of electricity bills, and hourly consumption data if you can get it
• Size your solar system around actual usage, not just available rooftop space
• Confirm whether your project crosses the 100 kW threshold
• Build battery sizing into your design from day one, not as a late addition
• Run the numbers on battery cost against your specific tariff and usage pattern
• Sort out your grid connection and Open Access requirements early in the process
• Look at total project cost, not just the solar panel price tag
• Work with an EPC partner who can handle solar, storage, and electrical work as one integrated project

Where Chirayu Power fits in

At Chirayu Power, we help you work out the right solar and battery sizing based on your actual usage — fitting both the new state rules and your budget, while looking at the complete picture: capacity, storage, electrical setup, and long-term savings. Planning a project above 100 kW or exploring Green Open Access? Now’s the time to check your plans against this rule.

A Few Questions We Keep Getting Asked

Does this apply to every solar project in Maharashtra?

No only new solar and renewable projects above 100 kW that need grid or Open Access connectivity. Anything below that threshold follows different rules.

 

I already have rooftop solar. Do I need to add a battery now?

No, existing systems aren’t required to retrofit storage, though the state is encouraging it. This mandate is for new projects going forward.

 

How much battery backup would a 200 kW solar plant need?

Around 100 kW of battery capacity.

 

Does this cover Green Open Access projects too?

Yes. Any new renewable project above 100 kW seeking Open Access transmission connectivity from 1 April 2026 falls under the same 50% storage rule.

 

Will the 50% requirement always stay the same?

Not necessarily. It’s up for review every two years, so expect it to evolve.

 

Will a battery actually save me money?

It depends entirely on your usage and tariff — there’s no flat answer here. A proper feasibility study will tell you your real numbers.

 

Should I hold off on my solar project because of this?

No reason to wait. Just make sure storage is part of the plan from the outset that’s what keeps you from redesigning everything halfway through, and gives you a clearer picture of your actual costs and savings.

 

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