How much do commercial solar panels cost in the UK in 2026?

The 2026 numbers

Installed cost of commercial solar PV in the UK currently runs:

£900-£1,200 per kWp for systems under 100 kWp (typical small managed office, professional services suite, ground-floor retail-office)
£780-£950 per kWp for systems 100-500 kWp (typical multi-let office, mid-sized HQ, serviced office building)
£700-£850 per kWp for systems above 500 kWp (typical headquarters, business park, multi-building campus)
£640-£780 per kWp for systems above 1 MWp (typical large business park, portfolio rollout)

Battery storage adds roughly £300-£450 per kWh of battery capacity installed, with the lower end for systems above 200 kWh capacity.

Solar carport over surface parking adds a structural premium of £300-£500 per kWp vs rooftop, reflecting steel canopy structure cost.

What’s included in the per-kWp number

The installed costs above cover the full project delivery: panels, inverters, mounting system, DC and AC cabling, switchgear modification (where needed), grid connection application and commissioning, structural and electrical commissioning to MCS/NICEIC standards, all required documentation, and 5-year workmanship warranty plus manufacturer warranties on panels (typically 25-30 years) and inverters (typically 10-15 years).

Not included: planning permission application fees (typically £120 Prior Approval, £200-£400 full planning), specialist heritage consultancy on listed buildings (typically £3,500-£8,000), or major switchgear replacement where the existing building infrastructure is end-of-life.

Worked example: 4,500 sqm Reading office, 320 kWp install

System scope: 320 kWp rooftop PV on existing flat roof. Two 125 kW string inverters integrated with existing 800A three-phase landlord supply. DC cable runs via existing rooftop plant rooms to main switchroom. No battery storage in this scope.

Installed cost breakdown (excluding VAT):

Panels (595 × 540W bifacial mono-PERC modules): £77,000
Inverters (2 × Solis 125 kW string): £15,500
Mounting (ballasted east-west, 100% roof penetration-free): £28,000
DC + AC cabling, isolators, switchgear modification: £21,500
Structural engineering + roof survey: £6,500
DNO G99 application + commissioning: £8,500
Project management + design: £18,000
Install labour (typical 6-8 weeks site presence): £74,000
Commissioning + documentation + handover: £12,000
5-year warranty + monitoring service: £8,000
Total: £269,000 (= £840/kWp)

For limited companies at current 25% corporation tax with full AIA available, the year-one tax saving is £67,250 — reducing effective net capex to £201,750.

Cost trends

Commercial solar capex per kWp has fallen roughly 30% in real terms since 2019, driven primarily by:

Panel manufacturing scale (China-led capacity expansion through 2023)
Inverter market maturation (Huawei + Sungrow + Solis price competition)
Improved installation productivity (typical 6-8 week site time vs 10-12 weeks five years ago)
DNO application process maturity

Forward expectations suggest a further 8-15% real-terms cost reduction through 2030 as battery prices fall and inverter integration consolidates. For most UK office projects, the marginal benefit of waiting is modest — the cumulative grid electricity cost of delaying a 5-year-payback project for two years usually exceeds any system cost reduction.

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