Solar Payback Period Calculator
Solar Payback Period Calculator — quick estimate
How fast does a rooftop solar plant pay for itself on your bill? Enter the monthly bill and tariff from your electricity bill, sanity-check the plant cost, and see payback, ROI and what 25 years of generation is worth.
Your bill & plant
Assumes 1,500 units/kWp/yr (north-India band) and that 90% of generation offsets billed units — Sunday and holiday generation rarely earns the full tariff.
Get the exact payback for your factory — free
Our solar team will size the plant on your actual load profile and tariff structure and send a proposal with post-tax payback, IRR and NPV.
Have a BOQ, drawing or tender for this scope? Send it for an item-wise rate-analysis review →
Your request is in
Your request reached our team with exactly what the preview showed. If an engineer needs your drawings, bill or data, they will use the number you gave.
Indicative, pre-tax simple payback — no escalation, degradation or O&M. For bankable numbers (IRR, NPV, post-tax) use the full financial model or ask for an engineered proposal.
Questions engineers and CFOs ask
What is a typical payback period for commercial rooftop solar in India?
Most C&I rooftop plants in north India pay back in 3 to 5 years. The two numbers that decide it are your landed tariff (printed on your electricity bill) and the installed cost per kW. A factory paying ₹9/unit recovers a plant far faster than an office paying ₹6.5/unit on the same roof.
Why does this show a longer payback than my vendor's quote?
This tool deliberately assumes only 90% of generation offsets billed units, because some generation lands on Sundays and holidays when the factory draws little. Quotes that assume every unit earns the full tariff, ignore that mismatch, and skip degradation will always look faster on paper — and slower in your accounts.
Is simple payback the right way to judge a solar investment?
It is the right first filter, not the final answer. Simple payback ignores tariff escalation (works in solar's favour), module degradation and O&M (work against it), and the time value of money. For a board or bank you want IRR and NPV over 25 years — our full financial model calculator computes exactly that with every assumption editable.
Does accelerated depreciation change the payback?
For profit-making companies, substantially. Solar plants qualify for 40% accelerated depreciation under the Income Tax Act, which shelters profit in the first years and can bring the effective payback down by roughly a year for a tax-paying firm. This calculator shows pre-tax payback; ask us for the post-tax working for your entity.
Got your number — what next?
A calculator gives you a first figure. These take it further.
The work itself
Read before you specify
The terms behind it
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One of 56 free MEPF and solar calculators on this site. Every input term is defined in the engineering glossary; the specification libraries, clearance guides and checklists for design teams are in the architects' section.
Need an exact BOQ, rate analysis or measurement sheet?
This is a quick engineering estimate. For tendering, billing or audit, our QS & estimation team prepares an item-wise BOQ, rate analysis and a verified measurement sheet to IS / CPWD norms — backed by 15+ years of estimating our own projects.