Solar calculator — 2026 UK pricing

Commercial solar calculator — system size, capex, payback after grants.

Enter your annual electricity spend and sector. The calculator estimates the system size that fits your demand, capex at 2026 UK prices, year-one savings, and post-grant payback. No email required, no obligation. For a properly modelled financial case run against your half-hourly meter data, the free funding review takes the next step.

Independent · no installer commission

180+

Projects

£42m

Secured

4.5yr

Avg Payback

MCS NICEIC RECC TRUSTMARK

Annual electricity spend (£) Your most recent annual electricity invoice total, ex-VAT Sector Average electricity unit rate (p/kWh) 2026 UK commercial average is 22–28p/kWh Funding route

Free funding review

Want a properly modelled case?

The calculator uses sector averages. The free funding review uses your actual meter data, real installer quotes and live grant windows.

Start Funding Review Call 020 4525 6101

No obligation. We don't charge for grant scoping.

Funding by asset class

The allowance depends on the asset, and most pages on this topic get it the wrong way round. Solar PV is special-rate expenditure (HMRC Capital Allowances Manual CA22335), so the 100% year-one route is the Annual Investment Allowance — Full Expensing is a main-rate measure and does not reach it. Battery storage, EV charging and heat pumps are main-rate plant, so Full Expensing genuinely does apply to those.

heat pump capex for commercial buildings
Main-rate plant, so Full Expensing does apply here.
commercial battery storage costs and ROI
Main-rate plant. Stacks with solar for self-consumption.
what commercial solar costs per kWp
Capex bands per kWp before any relief.
rooftop solar on industrial premises
Large roofs, high daytime load — the strongest case.
the Annual Investment Allowance explained for solar
Solar is special-rate, so AIA is the 100% year-one route.

Free funding review

Find out which 2026 schemes your site actually qualifies for

What you get, within one working day

1. A short written funding note naming every scheme your site qualifies for in 2026 — and the ones it does not.
2. Indicative system size and a capex band for your roof.
3. Year-one tax treatment per asset in £ — solar is special-rate expenditure, so the route is the Annual Investment Allowance; battery storage and heat pumps are main-rate plant, where Full Expensing does apply. Most pages get this the wrong way round.
4. Projected SEG export revenue at current rates.
5. Any red-flag eligibility or DNO issues we can see up front.

Covers solar PV, battery storage, EV charging and commercial heat pumps — separately or as one bundled project. If your project is a heat pump or a battery rather than a roof, say so in the message box and the note is written against that asset instead.

What we will not do

· We do not pass your details to multiple installers.
· We do not run a lead auction, and we never ask for your phone number.
· No marketing lists, no unsolicited calls.
· We are an independent funding consultancy — not an installer, and we take no installer commission.

Five questions. They are the eligibility test itself — scheme eligibility in 2026 turns on sector, tenure, site size and spend, so we cannot shortlist anything without them.

Business or organisation name * Site postcode * Determines nation, DNO region and which regional schemes apply. Sector * Approx. annual electricity spend * Roof tenure * Most funding routes and PPAs hinge on this. Work email *

We reply from funding@commercialsolargrants.co.uk. No phone number required, ever.

Explore this guide cluster

Commercial solar cost & ROI

What commercial solar actually costs in 2026, what it returns, and how the numbers are built — installation, payback and live calculators.

Pillar guideCommercial solar cost guideReal 2026 pricing by system size and building.