C&I Solar Project Financial Model
Size a rooftop plant against your actual consumption, then see generation, savings, payback, IRR and NPV — with every assumption visible and editable.
Your facility
I don't know my roof area
Estimate it: shed length × width, in feet. A typical single industrial bay is roughly 100 ft × 40 ft ≈ 4,000 sq.ft. Then subtract about 15% for skylights, walkways and shaded edges. We verify the real figure during the site survey.
Assumptions
Every figure below is an assumption, not a promise. Change any of them and the model updates instantly.
Monthly generation (year 1)
Seasonal shape is indicative only.
Cumulative cash position
Includes O&M and an inverter replacement in year 12.
What changes the answer most
Payback at different tariffs, holding everything else constant.
Indicative estimate only. Actual generation, savings and payback depend on site conditions, irradiation, tariff structure, system design, equipment selection, DISCOM regulations, financing terms and execution. Figures are not guaranteed and are subject to a site survey and electricity-bill analysis.
Want the detailed engineering report?
Our engineers will design for your exact roof and load, verify structure and DISCOM headroom, and send an approval-ready proposal. Your estimate above is attached automatically.
Your report request is in
Thanks! Our engineering team will send your tailored solar design & quote within one business day.
Questions engineers and CFOs ask
How does this calculator size my solar plant?
It sizes to the smallest of three limits — what your consumption can absorb, what your shadow-free roof can physically hold, and any DISCOM sanctioned-load cap. Sizing to the roof alone is the most common cause of a disappointing payback, because generation beyond your consumption is either exported at unfavourable rates or curtailed.
What is IRR and why does it matter more than payback?
IRR is the annual return the project earns on the capital tied up in it, expressed as a percentage — so you can compare a solar plant against any other use of the same money. Payback tells you when you get your capital back but ignores everything after that; a plant with a 4-year payback and 25-year life is a far better investment than the payback number alone suggests.
Why is the discounted payback longer than the simple payback?
Simple payback treats a rupee saved in year 8 as equal to a rupee saved today. Discounted payback applies your cost of capital first, so it is always the longer and more conservative figure. We show both because finance teams will ask for the discounted one.
Can I change the assumptions?
Yes — switch to Advanced mode and every assumption becomes editable: cost per kW, monthly yield, tariff escalation, module degradation, discount rate and O&M. Results update instantly. Each assumption carries a note explaining its basis so you can judge whether it fits your site.
Are these numbers a quotation?
No. They are an indicative model based on the assumptions shown on screen. Actual generation, savings and payback depend on site conditions, irradiation, your tariff structure, system design, equipment selection, DISCOM regulations and financing terms. A firm number requires a site survey and analysis of twelve months of electricity bills.