Why businesses add rooftop solar
Factories, warehouses, schools, hospitals, hotels, offices and cold storage run during daylight hours, so most of the solar generation is used on site at your full tariff. That makes the plant a predictable way to cut a large, recurring cost. Roofs you already own are idle assets, and a well-built plant has low running costs.
The financial case
- Bill savings. Every unit generated and used on site avoids a unit from the grid at your tariff.
- Tax depreciation. Solar qualifies for depreciation at 40% on the written down value. The benefit depends on your tax regime and commissioning date, so involve your chartered accountant.
- Lower GST on equipment. GST on solar equipment fell from 12% to 5% from 22 September 2025, with EPC contracts treated as 70% goods and 30% services for GST purposes, as described in the KERC order.
- Surplus export. For net-metered plants between 1 kW and 1,000 kW, BESCOM pays ₹3.11 per unit with DCR modules or ₹2.34 with non-DCR modules under the KERC order of 25 August 2026, locked for 25 years.
Note: The PM Surya Ghar subsidy does not apply to commercial or industrial connections.
A worked example (illustration only)
These numbers show the method, not a quote. Your actual figures depend on your roof, tariff, equipment and price.
| Item | Illustrative assumption |
|---|---|
| Plant size | 100 kW |
| Yearly generation | 100 kW x 4.2 units/day x 365 = about 153,000 units |
| Avoided tariff | ₹8 per unit |
| Yearly saving | about ₹12.2 lakh |
| Installed cost | ₹40,000 per kW = ₹40 lakh |
| Simple payback | about 3.3 years, before tax benefit |
| Depreciation tax saving, year one | 40% x ₹40 lakh x your tax rate |
Use the SunScore calculator with your own bill for a first estimate, then ask for a quotation based on a survey.
Module rules to plan for
MNRE has allowed net metering projects to commission with an exemption from ALMM List-II (solar cells) until 31 December 2026. After that date, net metering projects must comply with List-II, which in practice means modules with DCR cells. If your plant will commission near that date, we explain the cost and tariff effect in the proposal.
Engineering we cover
- Structural check of the roof and the right mounting: non-penetrative clamps for metal sheet roofs, or fixed structures on RCC.
- Load study from your 12-month bills and, where available, interval data.
- Inverter and string design, DC and AC protection, earthing and lightning protection.
- Zero-export or reverse-power protection where a diesel generator or a feeder limit applies.
- Metering, BESCOM application, synchronisation and commissioning.
- Safety, working-at-height planning and fire access on the roof.
Electrical inspectorate approval requirements apply to larger plants (BESCOM's portal lists an inspectorate notification for plants above 1 MW), so we confirm what is needed for your capacity at the start.
Our process
- Share your bills, sanctioned load or contract demand and roof details.
- Site survey and structural and electrical check.
- Proposal with design, generation, savings, payback and tax view.
- Order, approvals and procurement.
- Installation, testing and commissioning with BESCOM.
- Monitoring and AMC.
Frequently asked questions
Is there a government subsidy for commercial and industrial rooftop solar?
The central PM Surya Ghar subsidy is for residential consumers and for housing societies, not for commercial or industrial connections. The main financial benefits for a business are bill savings, tax depreciation and the surplus export tariff.
What is accelerated depreciation on solar?
Businesses that own a solar plant can claim depreciation at 40% on the written down value under the income tax rules. From 1 April 2026 the rule sits in the Income-tax Act, 2025, with the same 40% rate. Eligibility depends on your tax regime and commissioning date, so confirm with your chartered accountant.
What is the largest rooftop plant I can net meter in Karnataka?
Under the KERC tariff order of 25 August 2026, net metering covers 1 kW up to 1,000 kW, limited by your sanctioned load or contract demand. Gross metering and net billing are available up to the sanctioned load.
What export tariff will I get for surplus units?
For net-metered commercial and industrial plants from 1 to 1,000 kW, the KERC order of 25 August 2026 sets ₹3.11 per unit with DCR modules and ₹2.34 per unit with non-DCR modules, fixed for a 25-year agreement. Most industrial plants are sized to use nearly all generation themselves.
Will a rooftop plant work with my diesel generator?
Yes, with correct synchronisation and protection so the solar plant never feeds the generator. We design reverse-power protection and controls as part of the project.
Keep reading
Want a payback and depreciation view for your premises?
Share your bills and roof details. We prepare the plant size, savings, 40% depreciation view and payback for your factory or building. Tap Free Survey or call us.
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