Free Tool

Solar ROI & Payback Calculator

Calculate your exact payback period, 25-year savings, IRR, and CO₂ offset. See year-by-year how your solar investment grows.

Solar payback in India typically takes 4–7 years, with an IRR of 18–25% over the system's 25-year life.

Updated August 2026 Reviewed by the SolarOps360 Engineering Team

Enter Your System Details

Get your payback period, 25-year savings, IRR, and CO₂ offset instantly.

Example: a 5 kW system costing ₹3,00,000 pays back in 4.6 years, nets ₹23,74,812 over 25 years (IRR 24.3%), and offsets 6.2t of CO₂ every year. Enter your own numbers below.

Showing an example — enter your details above for your own numbers.

4.6
Payback (Years)
₹23,74,812
25-Year Profit
24.3%
IRR
6.2t
CO₂ Saved/Year

Year-by-Year Breakdown

Year Generation (kWh) Annual Savings (₹) Cumulative (₹)

Estimates assume ~1,505 kWh/kW/year generation with 0.5% annual panel degradation. Actual results vary by location, shading, and equipment.

How It Works

How This Calculator Works

  1. 1

    Enter system cost

    Type the total installed cost of the solar system in ₹, including panels, inverter, installation, and net meter charges.

  2. 2

    Enter system size

    Enter the solar system size in kW (kilowatts). If unsure, use our Solar System Size Calculator first.

  3. 3

    Enter your current electricity tariff

    Enter the per-unit (kWh) electricity rate you currently pay. Check your electricity bill for the rate — typically ₹5–10/unit in India.

  4. 4

    Set annual tariff hike

    Enter the expected annual electricity price increase in %. Historical data shows Indian tariffs rise 5–8% per year on average.

  5. 5

    Click Calculate

    See your payback period, annual savings, 25-year profit, IRR, and CO₂ offset instantly, plus a year-by-year savings breakdown table.

Definitions

Understanding Your Results

Payback Period
The number of years it takes for your cumulative electricity savings to equal your initial system cost.
25-Year Profit
Total savings over the system's 25-year lifetime, minus the upfront cost — your net financial gain.
IRR (Internal Rate of Return)
The annualised rate of return on your solar investment, treating it like any other financial asset — useful for comparing against FDs or mutual funds.
CO₂ Saved
Carbon emissions avoided each year by generating clean solar power instead of drawing from the grid, based on India's average grid emission factor.
FAQs

Frequently Asked Questions

What is the typical payback period for solar panels in India?
The payback period for solar panels in India is typically 4–7 years depending on system cost, electricity tariff, and location. On-grid residential systems in high-tariff states like Maharashtra or Delhi often achieve payback in 4–5 years, while states with lower tariffs may take 6–7 years.
How much money can I save with a 5 kW solar system over 25 years?
A 5 kW solar system generates approximately 7,000–8,000 kWh per year. At ₹8/unit with a 5% annual tariff hike, you save around ₹56,000 in year one, rising to over ₹1.8L in year 25. Total 25-year savings typically exceed ₹20–25 lakh for a ₹2.5–3L system investment.
What is IRR (Internal Rate of Return) for a solar investment?
IRR is the annualised rate of return on your solar investment. A solar system with a 5-year payback period and 25-year lifetime typically delivers an IRR of 18–25%, which is significantly better than fixed deposits (6–7%) or most mutual fund benchmarks over the same period.
How does electricity tariff hike affect solar savings?
Every 1% increase in annual electricity tariff accelerates your payback and increases total savings. At 5% annual tariff hike, the solar savings in year 10 are 63% higher than year 1. This makes solar increasingly valuable over time — your solar system cost is fixed, but grid electricity gets more expensive every year.
How much CO₂ does a solar panel system save?
In India, the grid emission factor is approximately 0.82 kg CO₂ per kWh. A 5 kW solar system generating 7,500 kWh per year saves approximately 6.15 tonnes of CO₂ annually — equivalent to planting 300+ trees or removing a car from the road for a year.

Explore More Free Tools

System Size

Enter your monthly electricity bill or units consumed. Get the exact system size (kW), number of panels, and rooftop area you need — for free.

Loan & EMI

Calculate your solar loan monthly EMI, interest vs principal breakdown pie chart, complete amortization schedule, and net monthly solar cashflow.

Quote Generator

Generate a professional, branded solar system quotation in minutes. Fill in customer and site details, and get a print-ready PDF quote.

Ready to run your whole EPC business like this?

SolarOps360 handles leads, projects, inventory, and billing — join 50+ Solar EPC companies already using it.

Book a Free Demo ← All Free Tools