SolarGridCheck

Land & Grid Screening

The Asset Auditor

Commercial Solar Feasibility & Savings Calculator (2026)

Screen your roof or car park in 30 seconds: system size, annual generation, bill saving and CO₂.

Assumptions updated August 2026Independent Assessment

Your Asset Details

Result Card

Potential System Size0 kWp
Annual Generation0 kWh
CO₂ Offset0 Tonnes
Est. Annual Bill SavingEnter your monthly bill
Upfront CostBelow typical funded-PPA minimum (30 spaces or 500 m²)

Enter your roof size, postcode and monthly bill to request a survey.

How to finance your commercial solar

CapEx (Buy it)

You pay upfront (£40k-£105k for 50-100 kW).

  • ✓ Highest Long-term ROI
  • ✓ Full Asset Ownership
  • ✗ High Capital Outlay

Asset Finance (Lease it)

Pay monthly, offset against tax.

  • ✓ Cashflow Positive
  • ✓ 100% Tax Deductible
  • • Medium ROI
Most Popular

Power Purchase Agreement (PPA)

£0 Upfront. Fund pays for everything. You get cheaper power. Read the full PPA guide →

  • ✓ Zero Capital Expenditure
  • ✓ Immediate Bill Reduction
  • ✓ Fully Maintained & Insured

Commercial Solar Panel Costs & ROI (2026)

Commercial solar costs £850-£1,100 per kW installed (ex-VAT) in 2026. For a business that uses most of its solar on-site, payback is typically 4-6 years.

System SizeCost RangeAnnual SavingsPayback
20 kW£18,000-£24,000~£3,6005-7 years
50 kW£40,000-£55,000~£9,0004-6 years
100 kW£75,000-£105,000~£18,0004-6 years

Savings assume 950 kWh per kWp a year, 75% of generation used on-site at 25p/kWh and the surplus exported at 4-15p/kWh. Costs ex-VAT, sub-100 kW systems at the upper end of the £/kW range.

15-25%
Annual ROI
4-6 yrs
Typical Payback
25+ yrs
System Lifespan
Revenue Multiplier

Don't just save on bills. Generate new revenue.

Add EV Charging to your solar car park project. Funded options available to monetize your parking spaces.

Calculate EV Revenue

Is your property eligible?

Most commercial solar car park installers require a minimum of 30 parking spaces or a roof area of at least 500 sq meters to ensure financial viability for a fully funded PPA Model.

Our commercial solar ROI calculator helps you assess viability for offices, industrial units, logistics centres, and retail parks. Projects falling below these thresholds may still be viable via CapEx or Asset Finance models.

How the estimate works: 8 m² of flat roof per kWp, 2.5 kWp per parking bay, 950 kWh per kWp a year, electricity at 25p/kWh. The bill saving counts only power used on-site (at most 75% of generation, and at most half of the usage implied by your bill); the rest is shown as export. CO₂ uses the DESNZ 2025 grid factor of 0.128 kg/kWh. A site survey replaces all of this with measured figures.

Popular: Solar Panels for Warehouses UK | 100kW Solar System Cost | London Solar Guide | EV Revenue Calculator | G98 vs G99 | Warehouse Energy Costs | Warehouse Solar Case Studies

Commercial Solar FAQs

Frequently Asked Questions

Commercial solar costs £850-£1,100 per kW installed (ex-VAT) in 2026. A typical 50kW system costs £40,000-£55,000 and a 100kW system £75,000-£105,000. Larger systems are cheaper per kW because design, scaffolding and the grid application are broadly fixed costs. Roof type, panel choice and installation complexity move the price.
A business that uses most of its solar on-site typically sees a 15-25% simple annual return and a 4-6 year payback, on a system that lasts 25+ years. The number that matters is daytime load: a site that exports most of its generation earns 4-15p/kWh on the surplus instead of saving 25p, and payback stretches accordingly.
A Power Purchase Agreement (PPA) lets you get solar panels installed at zero upfront cost. A third party owns and maintains the system, and you buy the electricity at a fixed rate lower than grid prices. Typical PPA rates are 30-50% below standard commercial electricity prices.
Direct grants are rare. Solar qualifies for the Annual Investment Allowance (100% first-year relief on up to £1m of plant a year); above that it is a special-rate asset with a 50% first-year allowance, not full expensing. VAT-registered businesses reclaim the VAT. The Smart Export Guarantee (SEG) pays 4-15p/kWh for surplus exported to the grid.
A 30kW commercial solar system generates around 28,500 kWh a year. What you save depends on how much of that you use on-site: at 25p/kWh and 75% self-consumption that is roughly £5,300 a year, with the surplus exported at 4-15p/kWh. Without storage, solar typically covers 30-50% of a business's annual electricity.
System size depends on your roof space and electricity usage. A 500m² flat roof typically fits a 50-60kW system (8-10m² per kWp once row spacing and walkways are allowed for). For PPA eligibility, most providers require minimum 30 parking spaces or 500m² roof area to ensure financial viability.