Going solar is one of the most significant financial decisions a homeowner can make — and also one of the most rewarding. This guide breaks down exactly what a rooftop solar system costs in India in 2025, which subsidies you can claim, and how to calculate your payback period to the month.
What Does a Solar System Cost in 2025?
Solar prices in India have fallen dramatically over the past decade. In 2025, a grid-connected rooftop solar system costs between ₹55,000 and ₹75,000 per kW for a complete, installed system — panels, inverter, mounting structure, wiring, and net metering. The exact figure depends on the brand of components, your roof type, and local installation complexity.
For a typical Bangalore home consuming 400–600 units per month, a 5 kW system is often the right size — bringing the total installed cost to approximately ₹2.75 lakh to ₹3.75 lakh before subsidies.
| System Size | Est. Cost (Before Subsidy) | PM Surya Ghar Subsidy | Net Cost | Monthly Generation |
|---|---|---|---|---|
| 1 kW | ₹65,000–₹75,000 | ₹30,000 | ₹35,000–₹45,000 | 120–140 units |
| 2 kW | ₹1.30–₹1.50 lakh | ₹60,000 | ₹70,000–₹90,000 | 240–280 units |
| 3 kW | ₹1.95–₹2.25 lakh | ₹78,000 | ₹1.17–₹1.47 lakh | 360–420 units |
| 5 kW | ₹2.75–₹3.75 lakh | ₹78,000 | ₹1.97–₹2.97 lakh | 600–700 units |
| 10 kW | ₹5.50–₹7.50 lakh | ₹78,000 | ₹4.72–₹6.72 lakh | 1,200–1,400 units |
The PM Surya Ghar Muft Bijli Yojana subsidy is capped at ₹78,000 regardless of system size above 3 kW. This means smaller systems get a proportionally larger subsidy benefit — a 3 kW system effectively gets 35–40% off.
Understanding Your Electricity Bill
Before sizing a solar system, you need to understand your current consumption and tariff slab. BESCOM (Bangalore's electricity provider) uses a tiered tariff structure — the more you consume, the higher the rate per unit. Heavy consumers pay ₹7.40–₹8.50 per unit, making solar savings much larger for high-bill households.
BESCOM Tariff Slabs (2024–25)
| Monthly Units | Rate per Unit | Typical Monthly Bill |
|---|---|---|
| 0–50 units | ₹3.05 | ₹150–₹200 |
| 51–100 units | ₹5.45 | ₹400–₹600 |
| 101–200 units | ₹6.10 | ₹800–₹1,400 |
| 201–500 units | ₹7.40 | ₹1,500–₹4,000 |
| Above 500 units | ₹8.50 | ₹4,000+ |
If your home consumes 400 units per month at ₹7.40/unit, you're spending roughly ₹3,000 per month or ₹36,000 per year. A 3–4 kW solar system can offset 80–100% of this bill.
How to Calculate Your Payback Period
The payback period is the number of years it takes for cumulative electricity savings to equal your initial investment. Here's how to calculate it step by step:
- Annual generation: A 1 kW system in Bangalore generates approximately 1,400–1,600 units per year (4–4.5 units/day on average).
- Annual savings: Multiply your annual generation by your current tariff rate. At ₹7.40/unit, a 3 kW system saving 4,200 units = ₹31,080/year.
- Add net metering income: Surplus units exported to the grid are credited at approximately ₹3.50–₹4.50/unit by BESCOM.
- Divide net cost by annual savings: Net cost ÷ Annual savings = Payback years.
Profile: 4-bed house, 500 units/month, bill ₹4,000/month
System: 5 kW, installed cost ₹3.50 lakh, subsidy ₹78,000, net cost ₹2.72 lakh
Annual generation: ~7,000 units · Annual savings: ₹59,500 at ₹8.50/unit
Payback period: 4.6 years · Profit over 25 years: ~₹12 lakh
What About Battery Storage?
Lithium-ion battery storage adds ₹60,000–₹1,20,000 per 5 kWh of capacity to your system cost. For most grid-connected Bangalore homes, batteries are optional — net metering effectively acts as your "grid battery." However, if power cuts are frequent in your area or you need backup for critical loads, a battery adds significant value.
Component Quality and What to Look For
Not all solar quotes are equal. The three components that most impact long-term performance and value are:
- Panels: Look for Tier-1 manufacturers (Jinko, LONGi, REC, Waaree, Adani). Efficiency above 20%, 25-year performance warranty, and linear degradation of no more than 0.55% per year.
- Inverter: The inverter is the most failure-prone component. Sungrow, SMA, Fronius, and Delta are reliable brands with Indian service networks. Avoid cheap no-name inverters.
- Mounting: Galvanised or anodised aluminium mounting structures rated for your wind zone. Cheap iron structures rust and fail within 5 years.
Key Questions to Ask Before You Sign
- Is the quote for a MNRE-approved system eligible for PM Surya Ghar subsidy?
- Does the installer handle net metering application with BESCOM?
- What are the panel and inverter warranty terms, and who backs them in India?
- What is the generation guarantee (performance ratio) in the proposal?
- Is AMC (annual maintenance contract) included for the first year?