What rooftop solar costs in India, and what it actually saves

Residential rooftop solar runs about ₹55,000–70,000 per kW installed, and commercial or industrial systems drop to ₹38,000–50,000 per kW because of scale. So a 3 kW home system is roughly ₹1.8–2.1 lakh before subsidy, a 50 kW commercial plant is ₹20–25 lakh, and a 100 kW industrial plant is ₹37–50 lakh. Price per kW falls as system size rises, which is why small systems have a worse raw payback than large ones even with the subsidy.

Up to ₹78,000, and only for residential rooftops. The structure is ₹30,000 for the first kW, ₹60,000 for 2 kW, and ₹78,000 for any system of 3 kW or more — the subsidy is capped there, so a 10 kW home system receives the same ₹78,000 as a 3 kW one. Commercial, industrial and institutional rooftops get no central subsidy at all under this scheme; their economics come from tariff savings and accelerated depreciation instead.

Roughly 100 square feet per kW for a standard rooftop installation. So 3 kW needs about 300 sq ft of shade-free roof, 50 kW needs about 5,000 sq ft, and 100 kW needs around 10,000 sq ft. Elevated structures over parking or sheds can reduce the footprint penalty, and high-efficiency panels shave perhaps 10–15% off the area, but the 100 sq ft per kW rule is the right starting point for planning.

Typically three to five years for a commercial or industrial system, and four to six years for residential after subsidy. The driver is your current tariff: if you pay ₹9–12 per unit as a commercial consumer, every unit you self-generate saves that full amount, so payback is fast. A home paying ₹7 per unit in a low slab saves less per unit and takes longer. Panels are warranted for 25 years, so everything after payback is effectively free power.

About 4 to 4.5 units per kW per day in most of India, or roughly 1,400–1,600 units per kW per year. Gujarat and Rajasthan sit at the top of that range thanks to high irradiance; coastal and high-rainfall regions sit lower. For a quick estimate, multiply system size in kW by 4 to get daily units — a 50 kW plant produces around 200 units a day, or about 6,000–7,000 units a month.

Net metering lets you export surplus daytime generation to the grid and offset it against what you draw at night, so you are billed only on the net. This is what makes solar work for buildings whose load does not match the sun. The catch is that net-metering caps and rules vary sharply by state — some states limit commercial net metering, restrict system size to a percentage of sanctioned load, or offer only net billing at a lower export rate. Confirm your state's current policy before sizing a system.

Yes. Solar power generating systems qualify for accelerated depreciation under the Income Tax Act, which lets a profitable business write off a large share of the asset value in the early years and substantially improves post-tax returns. This is often worth more to a commercial buyer than the residential subsidy is to a homeowner. The exact rate and how it applies to your entity depends on your tax position, so have your CA confirm it before you model returns — we are not tax advisors.

Yes, and it is the single best combination in this market, because an EV charging station's biggest running cost is electricity. A solar array sized to your daytime charging load replaces grid units costing ₹8–12 with self-generated units costing effectively nothing after payback, which widens your margin on every kWh you sell. The two also share infrastructure: the same site survey, the same load study, the same electrical contractor and often the same transformer upgrade. Doing them together is materially cheaper than doing them a year apart.

Panel cleaning every two to four weeks and an annual electrical inspection. Dust is the main enemy in India — an uncleaned array can lose 15–25% of output in a dusty industrial area. There are no moving parts, so failures are rare; the inverter is the component most likely to need replacement, typically once in the system's life at around 10–12 years. Most commercial installers offer an AMC covering cleaning, monitoring and inverter support.

Output drops roughly 40–60% on heavily overcast monsoon days and is zero at night, which is exactly what net metering or a battery is for. A grid-connected system without batteries simply draws from the grid when the sun is not producing, and your annual generation estimate already averages the monsoon in — which is why solar is sized against annual units, not best-day output. Batteries only make financial sense if you need backup power anyway or your state has poor net-metering terms.