Solar Panel ROI Calculator: How Long to Recover Your Investment in India

Solar Panel ROI: Is It Worth the Investment?

The short answer: yes, overwhelmingly. Rooftop solar in India has a payback period of 3-6 years and panels last 25+ years. That's 20 years of free electricity. Here's how to calculate your exact ROI.

ROI Formula

Payback Period = Net System Cost / Annual Savings

Where:

• Net System Cost = Total Cost - Government Subsidy
• Annual Savings = Annual Units Generated × Electricity Tariff

Real Example: 3 kW System in India

Parameter	Value
System Size	3 kW
Total Cost	₹1,95,000
PM Surya Ghar Subsidy	₹78,000
Net Cost	₹1,17,000
Daily Generation	12-13 units
Annual Generation	4,500 units
Electricity Tariff	₹6/unit (average)
Annual Savings	₹27,000
Payback Period	4.3 years
25-Year Net Savings	₹5,58,000

City-wise Solar Generation (per kW installed)

City	Daily Units/kW	Annual Units/kW
Chennai	4.2-4.5	1,533-1,643
Bangalore	4.0-4.3	1,460-1,570
Mumbai	3.8-4.2	1,387-1,533
Delhi	4.0-4.5	1,460-1,643
Hyderabad	4.3-4.6	1,570-1,679
Jaipur	4.5-5.0	1,643-1,825
Ahmedabad	4.4-4.8	1,606-1,752

Factors That Improve ROI

• Higher electricity tariff: States like Maharashtra (₹8-12/unit) have faster payback than states with ₹4-5/unit tariffs
• Net metering: Sell excess power back to the grid at ₹2-3/unit
• Increasing tariffs: Electricity prices rise 3-5% annually, making your savings worth more each year
• Correct system sizing: Don't oversize. Match your system to your actual consumption

Factors That Hurt ROI

• Shading: Even 10% shading can reduce output by 30-50% with string inverters
• Dust: In dusty cities, panels need cleaning every 2-4 weeks
• Poor installation: Wrong tilt angle or orientation reduces output significantly
• Cheap panels: Low-quality panels degrade faster (1-2%/year vs 0.5% for premium brands)

25-Year Financial Summary (3 kW System)

• Total investment: ₹1,17,000 (after subsidy)
• Total electricity generated: ~1,08,000 units
• Total savings (accounting for 3% annual tariff increase): ₹8,50,000+
• Return on investment: 627%
• Internal rate of return (IRR): 22-28%

That's a better return than most mutual funds, fixed deposits, or real estate investments.

Use our Solar Calculator to estimate your exact savings, or find installers in your city through our Solar Panel Directory.