Solar for Business in India: Rooftop vs Open Access Costs

Your options

Solar from a solar park

No roof needed. See your price per unit after grid fees, co-owning the plant or just buying the power.

Open solar park calculator

Solar on your own roof

Buy the system or let a solar company install it and pay per unit. Upfront cost, payback and savings.

Open rooftop calculator

Fees in your state

Grid fees, surcharges and banking rules, with every figure dated and sourced.

See state fees

Three ways to go solar, side by side

	Own rooftop system (CAPEX)	Rooftop, pay per unit (RESCO)	Solar park via open access
Upfront cost	₹30,000–50,000 per kW	None	None as a buyer; 26% equity for group captive
What you pay after	Maintenance, about ₹4–5 lakh per MW a year	₹3.50–6 per unit for 15–25 years	PPA rate plus grid fees: about ₹4.50–5.50 (group captive) or ₹6–7 (third party) landed
Tax benefit	40% accelerated depreciation	None; the developer claims it	Depends on structure
Typical payback	3 to 5 years	Saves from day one	Saves from day one if landed cost beats your tariff
Best for	Owners with a strong roof and tax to set off	Rented buildings or no capital budget	Loads of 100 kW or more that the roof can’t cover

Ranges from 2026 industry sources. Open access landed costs rose in 9 of 13 states in the second quarter of 2026, so check current quotes.

Rooftop or solar park?

Rooftop solar has no grid fees because the power is used where it is made, so it usually gives the lowest price per unit. The limit is your roof. When the roof can’t carry the load you need, a solar park elsewhere in your state sends power to you through the grid, and the grid fees decide what it really costs.

Why the way you buy matters

Co-owning at least 26% of a solar plant (group captive) removes two of the biggest grid fees, which typically makes solar park power ₹1.50 to ₹2.00 a unit cheaper than buying it outright from a developer. The solar park calculator shows both side by side.

What drives your saving

Your current price per unit. Divide your monthly bill by the units used. Commercial and industrial tariffs of ₹8 to ₹10 a unit leave the most room to save.
The structure. Owning a rooftop system or co-owning a solar park plant removes fees that a straight power purchase pays.
Your state’s grid fees. They add ₹1.50 to ₹3.50 a unit to solar park power, and they change with each tariff order.
When you use power. Solar is produced by day, so night-heavy loads depend on banking rules.

A quick way to decide

Measure the shade-free roof you control. Each kW of rooftop solar needs about 100 sq ft.
Work out how much of your yearly use that roof can cover. Many factories and warehouses can cover 20 to 40% from their own roof.
Cover the rest with a solar park through open access, if your contracted load is 100 kW or more.
Compare group captive and a third-party PPA for the park share before you sign.

What commercial rooftop solar costs in 2026

Installed prices for commercial rooftops run from about ₹30,000 to ₹50,000 per kW. Bigger systems sit at the lower end because the inverter, cabling and labour are spread over more panels.

System size	Installed cost	Units a year (about 1,400 per kW)
50 kW	₹15–25 lakh	About 70,000
100 kW	₹30–50 lakh	About 1.4 lakh
500 kW	₹1.5–2.5 crore	About 7 lakh
1 MW	₹3–5 crore	About 14 lakh

What moves the price

Indian-made cells (DCR). In April 2026 DCR TOPCon modules cost about ₹22 a watt against about ₹14 for imported-cell modules, roughly ₹8,000 more per kW. Net-metered and open access projects commissioned from 1 January 2027 must use them; projects commissioned by 31 December 2026 are exempt.
GST. Solar devices moved to 5% GST from 22 September 2025. A turnkey contract is usually taxed on a 70:30 goods and services split, which works out to about 8.9% overall. Confirm the treatment with your CA.
Structure. Elevated or long-span structures on sheds and car parks add cost over a flat RCC roof.

Worked example: 100 kW on a factory roof

A factory in Pune pays about ₹9 a unit and puts 100 kW on its roof for ₹40 lakh. The system makes about 1.4 lakh units a year, all used on site, so it saves about ₹12.6 lakh a year. Simple payback is a little over three years.

Accelerated depreciation shortens that further. Solar plants are depreciated at 40% on the written-down value. If the system is in use for 180 days or more in the financial year, the full 40% applies in year one; commissioned later, only 20% is allowed that year and the rest carries forward.

Commissioned	Depreciation in year one	Tax saved in year one at 25.17%
By about 30 September (180+ days in use)	₹16 lakh	About ₹4 lakh
From October onwards	₹8 lakh	About ₹2 lakh

Companies on the concessional 25.17% rate under section 115BAA can still claim the 40%; what they lose is the extra additional depreciation. The rate and the 180-day rule carry over under the Income-tax Act 2025 from April 2026. Have your CA confirm before you plan around the date.

Frequently asked questions

How much does a 100 kW commercial rooftop system cost?

About ₹30 to ₹50 lakh installed in 2026, depending on the structure, panel type and whether DCR panels are needed.

Can a business get the PM Surya Ghar subsidy?

No. PM Surya Ghar is for homes. Businesses that buy a system claim 40% accelerated depreciation instead.

What is the payback on commercial rooftop solar?

Usually 3 to 5 years for a business paying ₹8 to ₹10 a unit, and less once depreciation is counted.

What is the difference between CAPEX and RESCO?

Under CAPEX you buy and own the system. Under RESCO a solar company installs it at no cost to you and you pay a fixed rate per unit for 15 to 25 years.

Who can buy solar through open access?

Consumers with a contracted load of 100 kW or more under the Green Energy Open Access Rules, subject to their state’s regulations.

Fees by stateGujarat Karnataka Maharashtra Rajasthan

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Sources

Figures last checked on 29 September 2026.