Solar panel cost calculator UK for businesses
Work out the indicative installed cost, yearly savings and payback of solar panels for a commercial site, such as a warehouse, factory, school or office. Built for business roofs, not homes.
Four short steps. You'll get an indicative view of system size, annual benefit and financed cashflow - then a Solar Britain specialist can take it forward.
- 1Site details
- 2Energy usage
- 3Roof details
- 4Finance interest
This calculator provides an initial estimate only. A full proposal requires site-specific checks including roof suitability, electricity usage, planning considerations, grid connection, export permissions and finance eligibility.
How the solar panel cost calculator works
Your inputs: postcode, roof area, electricity price (or monthly bill) and, if you have it, yearly usage in kWh. Usage pattern and daytime demand refine the result.
Our assumptions: a UK commercial cost band per kWp that falls as systems get bigger, local solar yield for your postcode area, and the share of power used on site versus exported. All results are indicative.
Typical UK commercial solar panel costs by system size
| System size | Installed cost | £/kWp | Payback |
|---|---|---|---|
| 50 kWp | £47,500 - £55,000 | £950 - £1,100 | 4.5 - 6 yrs |
| 100 kWp | £85,000 - £98,000 | £850 - £980 | 4 - 5.5 yrs |
| 250 kWp | £190,000 - £215,000 | £760 - £860 | 3.8 - 5 yrs |
| 500 kWp | £360,000 - £410,000 | £720 - £820 | 3.5 - 4.5 yrs |
| 1 MWp | £680,000 - £780,000 | £680 - £780 | 3.5 - 4.5 yrs |
Indicative 2026 figures before tax relief, assuming high daytime self-use. See the full commercial solar panel cost guide, ROI and payback guide, funding options or solar potential by postcode. Ready for firm numbers? Request a free feasibility review.
Solar panel cost & savings - common questions
How UK commercial solar savings are calculated, typical costs and what to expect from the figures above.
How do you calculate solar panel savings?
Annual solar savings = annual generation (kWh) × the share you use on site × your electricity rate (p/kWh), plus any surplus exported to the grid at the export tariff. This calculator runs that maths using your roof area, postcode, electricity rate and usage profile.
How much will solar panels save me per year in the UK?
Indicative savings range from roughly £8,000–£15,000/yr for a small commercial roof (around 50 kWp) up to £150,000+/yr for large industrial roofs (500 kWp+). The bigger the daytime self-consumption, the better the return.
How much do commercial solar panels cost in the UK?
Commercial solar in the UK typically costs around £650–£1,100 per kWp installed in 2026, before tax relief. A 100 kWp system is around £85k–£98k and larger systems cost less per kWp. Final pricing depends on roof type, electrical works, access and inverter choice.
How accurate is this solar savings calculator?
It's indicative only - designed to show whether your site is worth investigating. The next step is a finance review to lock in the funding route, then a desktop and site survey, structural and electrical checks, half-hourly usage data, DNO/G99 review and a tailored finance model in the full proposal.
How much do solar panels save per month?
Roughly your annual saving ÷ 12, weighted toward summer months when generation peaks. Most UK commercial sites generate around 60% of annual output between April and September.
What information do I need to use the calculator?
Just your postcode, approximate roof area in square metres, and ideally your electricity rate (p/kWh) or monthly bill. Annual kWh usage gives the most accurate estimate but is optional.
Can I use this calculator for my home?
No. This is a solar panel cost calculator for UK businesses, schools and other commercial sites, usually 30 kWp and above. Home systems have different costs and are not covered.
What affects commercial solar payback?
How much of the power you use on site during the day, your electricity price, system size, roof type and access, grid connection work and the funding route. High daytime use and higher tariffs shorten payback.