Commercial Solar Payback Calculator
Estimate the cost, savings, payback and carbon reduction of commercial solar for your business in seconds, including the effect of tax relief.
What you’ll see
Your Estimate
For guidance only, excluding VAT. Based on typical UK commercial prices, a simple estimate of on-site use, panel output dropping 0.5% per year and an approximate carbon figure for grid power. Not tax advice.
How the Calculator Works
The calculator estimates how much electricity your system will generate, how much of it your business will use on site, and how much you’ll save by not buying that power from the grid. Any surplus is valued at your export rate.
- System cost uses typical UK installed prices, which get cheaper per kWp as systems get larger. Enter your own quote to use that instead.
- Tax relief assumes the full cost is claimed under the Annual Investment Allowance.
- Payback includes your chosen energy price rise and a small drop in panel output each year.
How to Improve Your Payback
- Size the system to your demand: using more of your solar on site is worth far more than exporting it.
- Add battery storage: store daytime surplus for early mornings, evenings or peak times.
- Claim tax relief: capital allowances (tax relief on equipment) can cut the real cost a lot.
- Choose quality equipment: better panels and inverters keep performing for longer.
If you use most of your power during working hours, solar is usually one of the fastest-paying energy investments you can make.
Getting Accurate Figures
This calculator gives a good first idea. For figures you can take to your board, bank or accountant, we’ll:
- Analyse your half-hourly electricity data.
- Survey your roof, structure and electrical installation.
- Work out generation using your exact location, roof direction and shading.
- Compare buying, finance and PPA options.
Frequently Asked Questions
How accurate is the calculator?
It’s a good guide for early planning, but real results depend on your roof, shading, usage pattern and tariff. A site survey gives accurate figures.
Does it include VAT?
No. Prices exclude VAT, which VAT-registered businesses can usually reclaim on commercial installations.
What’s a good payback period?
Many well-designed commercial systems pay back in 3 to 7 years, with a lifespan of 25 years or more.
Is there a calculator for homes?
Yes. Our domestic solar page has a calculator designed for households.
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