Solar Panel Calculator
Calculate your rooftop solar investment — cost, savings, payback period, government subsidy, and environmental impact.
Typical home: 3-10 kW
India avg: ₹35-50/watt (with installation)
India avg: 4-6 hours (varies by state)
Check your electricity bill for exact rate
PM Surya Ghar Muft Bijli Yojana
The Government of India's PM Surya Ghar Muft Bijli Yojana aims to install rooftop solar on 1 crore households. The scheme offers substantial subsidies to make solar affordable:
| System Size | Subsidy per kW | Total Subsidy |
|---|---|---|
| Up to 2 kW | ₹30,000/kW | Up to ₹60,000 |
| 3 kW | ₹30,000 (first 2 kW) + ₹18,000 (3rd kW) | ₹78,000 |
| Above 3 kW | Same as 3 kW (no additional subsidy) | ₹78,000 (max) |
Eligibility
- Must be a residential electricity consumer
- System must be grid-connected (on-grid or hybrid)
- Must be installed by an empanelled vendor
- Apply through the National Portal at pmsuryaghar.gov.in
Understanding Solar Panel ROI
Solar panel return on investment (ROI) measures how quickly your solar installation pays for itself through electricity savings. In India, with high electricity rates and generous government subsidies, residential solar systems typically pay back in 3-5 years.
Key Factors Affecting Solar ROI:
- Location: Rajasthan, Gujarat, and southern states get more sunlight (5-6+ hours)
- Electricity Rate: Higher rates mean faster payback — rates vary ₹4-12/kWh across states
- System Size: Larger systems cost less per watt but the 3 kW subsidy cap matters
- Panel Quality: Monocrystalline panels (higher efficiency) vs polycrystalline (lower cost)
- Net Metering: Sell excess power back to grid for credits (available in most states)
How to Use This Solar Calculator
- Enter your desired solar system size in kilowatts (kW)
- Input the cost per watt (ask local installers for quotes)
- Set your area's average peak sunlight hours per day
- Enter your current electricity rate from your bill (₹/kWh)
- Toggle the government subsidy to see the difference
- Click "Calculate Solar ROI" to see your complete analysis
Pro Tip
Start with a 3 kW system to maximize the per-kW subsidy benefit. You can always expand later. A 3 kW system generates enough for most Indian households (300-400 units/month).
State-wise Solar Subsidies & Per-kW Net Cost (India)
Central government PM Surya Ghar scheme gives ₹30,000-78,000 subsidy. Many states add their own. Net cost after subsidies varies dramatically — same 3kW system can be ₹1.2 lakh net in Gujarat vs ₹1.9 lakh net in Karnataka. Reference matrix:
| State | Central subsidy | State top-up | 3kW net cost | Payback (yrs) |
|---|---|---|---|---|
| Gujarat | ₹78,000 | ₹30,000 | ~₹1.2 L | 3-4 |
| Maharashtra | ₹78,000 | — | ~₹1.5 L | 4-5 |
| Delhi | ₹78,000 | ₹2,000/kW | ~₹1.5 L | 4-5 |
| Tamil Nadu | ₹78,000 | — | ~₹1.7 L | 5-6 |
| Karnataka | ₹78,000 | — | ~₹1.9 L | 6-7 |
| Uttar Pradesh | ₹78,000 | ₹15,000/kW | ~₹1.2 L | 3-4 |
| West Bengal | ₹78,000 | — | ~₹1.8 L | 6-7 |
| Kerala | ₹78,000 | 10% | ~₹1.6 L | 5-6 |
Net cost = installed cost (~₹65k/kW for 3kW) minus central subsidy minus state subsidy. Payback in years assumes 4-5 kWh/day generation at ₹6-8/unit retail electricity. Confirm subsidy with your state DISCOM portal — schemes change yearly.
Three Things Solar Sales Pitches Skip
1. Inverter replacement at year 10-12
Solar panels last 25+ years. Inverters last 10-12. Plan to spend ₹15,000-40,000 on inverter replacement around year 10. Most ROI calculations skip this — it adds ~2 years to true payback.
2. Net metering vs gross metering
Net metering = excess goes to grid, you only pay net consumption. Best deal. Gross metering = you sell ALL generation to DISCOM, buy back ALL consumption — typically pays you less per unit than retail rate. Confirm which your state offers.
3. Roof type affects feasibility
RCC flat roof: best. Tiled sloped roof: fine. Tin sheet: works but reduces panel life. North-facing slope: avoid (low India sun angle). Always get the installer to assess physically — quotes from online calculators assume ideal conditions.
Frequently Asked Questions
How much does a solar panel system cost in India?
A residential solar panel system in India typically costs ₹35-50 per watt including installation. A 5 kW system costs around ₹1.75-2.5 lakh before subsidy. With the PM Surya Ghar subsidy, you can save up to ₹78,000.
What is the PM Surya Ghar Muft Bijli Yojana subsidy?
The PM Surya Ghar scheme provides government subsidy for rooftop solar: ₹30,000/kW for the first 2 kW and ₹18,000/kW for the 3rd kW, with a maximum subsidy of ₹78,000. It is available for residential grid-connected rooftop solar systems.
What is the payback period for solar panels in India?
With current electricity rates and subsidies, most residential solar systems pay back in 3-5 years. After payback, you get essentially free electricity for the remaining 20+ years of panel life.
How long do solar panels last?
Solar panels typically last 25-30 years with minimal maintenance. Most manufacturers provide a 25-year performance warranty guaranteeing at least 80% of original output. Panel efficiency degrades by about 0.5% per year.
How many kW solar panels do I need for my home?
Check your monthly electricity bill. A 1 kW system generates about 4-5 units (kWh) per day. If you use 300 units/month, a 3 kW system would cover most of your usage. A 5 kW system is ideal for homes with 400-500 units monthly consumption.
Does solar work during monsoon/cloudy days?
Solar panels produce less energy on cloudy days (20-30% of peak output) but still generate power. Annual calculations already account for seasonal variations. Grid-connected systems let you draw from the grid when solar output is low.