Estimate savings, PM Surya Ghar subsidy, payback period, and your carbon footprint reduction
Includes 5% annual tariff escalation and 0.5% panel degradation
| Year | Generation (kWh) | Tariff (₹/kWh) | Annual Saving | Cumulative Saving | CO₂ Offset (kg) |
|---|
The PM Surya Ghar scheme provides central subsidies for residential rooftop solar installations up to 10 kW. The subsidy is ₹30,000 per kW for the first 2 kW, ₹18,000 per kW for the next 1 kW (2-3 kW), and a flat ₹78,000 for any system above 3 kW up to 10 kW. The subsidy is credited directly to the beneficiary's bank account after successful installation and inspection by the DISCOM. Only on-grid (grid-connected) systems installed by MNRE-empanelled vendors qualify — off-grid and battery-based systems are not eligible.
System sizing depends on your monthly electricity consumption and your location's solar irradiance. In India, 1 kW of rooftop solar generates approximately 4 to 5 units (kWh) per day, varying by region — Rajasthan and Gujarat see 5+ units/day while northeastern states average 3.5 units/day. A typical Indian household consuming 300-400 units per month needs a 3 kW system. Each kW requires about 100 sq ft of shadow-free roof area, so a 3 kW system needs roughly 300 sq ft unobstructed between 9 AM and 4 PM.
With the PM Surya Ghar subsidy, most residential systems achieve payback in 3 to 5 years. After payback, you receive essentially free electricity for the remaining 20+ years of the panel's life. Considering typical electricity tariff escalation of 5-7% per year, the 25-year lifetime savings from a 3 kW system can exceed ₹15-25 lakh. The effective return on investment often surpasses 20% annually, significantly better than fixed deposits or PPF.
India's electricity grid has a weighted average emission factor of approximately 0.72 kg CO₂ per kWh (Central Electricity Authority, 2023), primarily due to coal-fired power plants. A 3 kW rooftop solar system generating about 4,200 kWh per year offsets roughly 3,000 kg (3 tonnes) of CO₂ annually. Over 25 years, this adds up to approximately 65-70 tonnes of CO₂ — equivalent to planting about 135 trees or taking a car off the road for 7 years.
Most states in India offer net metering, where excess solar power exported to the grid earns credits against your electricity bill. Under net metering regulations, your meter runs backward when you export power and forward when you consume from the grid. At the end of the billing cycle, you pay only for the net consumption. Some states have moved to gross metering or net billing with feed-in tariffs, where exported power is compensated at a lower rate than the retail tariff.
Solar panels require minimal maintenance — periodic cleaning (every 2-4 weeks) and annual inverter checks. Modern panels come with 25-year performance warranties guaranteeing at least 80% output at end of life, with typical annual degradation of only 0.5-0.7%. Inverters usually last 10-15 years and may need one replacement during the panel lifetime. Total maintenance costs are typically ₹2,000-₹5,000 per year for residential systems.
An on-grid residential system costs ₹55,000-₹75,000 per kW before subsidies. After the PM Surya Ghar subsidy, a 3 kW system typically costs ₹1.1-₹1.5 lakh out of pocket, down from ₹1.8-₹2.1 lakh.
₹30,000/kW for the first 2 kW, ₹18,000/kW for 2-3 kW, and a flat ₹78,000 for systems above 3 kW (up to 10 kW). Only on-grid systems by MNRE-registered vendors qualify.
With India's grid emission factor of ~0.72 kg CO₂/kWh, a 3 kW system offsets roughly 3,000 kg of CO₂ per year — equivalent to planting about 135 trees.
With subsidy: 3-5 years. Without subsidy: 5-7 years. After payback, you get free electricity for the remaining 20+ years of panel life.
Approximately 100 sq ft of shadow-free roof area per kW. A 3 kW system needs ~300 sq ft. The area must be free from shadows between 9 AM and 4 PM.