250kWp commercial solar PV cost in the UK (2026)
At 2026 prices, a 250 kWp commercial solar PV system costs £175,000 - £215,000 installed (excl. VAT). After 100% Full Expensing for limited companies, net cost is around 25% lower. Typical post-tax payback: 3.2-4.9 years.
250 kWp cost summary
| System size | 250 kWp |
| Installed cost range (2026, excl. VAT) | £175,000 - £215,000 |
| £ per Wp | £0.70 - £0.86 |
| Number of panels (450W modules) | ~550 |
| Roof area required | ~1,400 m² |
| Annual generation (UK avg) | 237,500 kWh |
| Best fit for | large factory, supermarket, warehouse, hospital wing, university campus building, 5+ school MAT shared site |
| Best grant stack | Full Expensing + SEG + REGO + (manufacturing) IETF candidacy + regional grant £10k-£30k |
Year-1 maths breakdown
Worked example for a limited company at the 25% main corporation tax rate, with typical self-consumption assumptions for this system size.
| Gross capex (mid) | £195,000 |
| 100% Full Expensing tax saving (25% CT) | -£48,750 |
| Net effective cost | £146,250 |
| Annual self-consumption (45%) | 106,875 kWh saving £25,650/year |
| Annual SEG export (55%) | 130,625 kWh earning £3,919 - £19,594/year |
| Total year-1 savings/revenue | £29,569 - £45,244 |
| Post-tax payback | 3.2 - 4.9 years |
Typical roof & site requirements for 250 kWp
- Unshaded roof area: ~1,400 m² needed for 550 × 450W panels
- Roof condition: 15+ years remaining life expected — older roofs may need refurbishment first (adds £30-300k depending on size)
- Roof structure: imposed load 12-25 kg/m² — modern portal-frame and composite roofs typically fine; some 1960s-80s structures need Cat 2 survey
- Electrical service: three-phase G99 connection required; rural sites may need DNO capacity study (5-11 weeks lead time)
- Planning: typically permitted development for commercial rooftop solar; listed buildings and conservation areas require consent
- Insurance: notify your insurer before installation; typical premium impact £150-£800/year additional
Best grant fit for 250 kWp
Recommended grant stack
Full Expensing + SEG + REGO + (manufacturing) IETF candidacy + regional grant £10k-£30k
Use the free eligibility calculator for a personalised grant match against your specific sector, postcode and ownership structure.
Generation & savings model
This page uses conservative 2026 assumptions:
- UK average insolation: 950 kWh/kWp/year
- Tier 1 panel pricing: £0.18/Wp landed
- Inverter pricing: £0.07/Wp
- Mounting + BOS: £0.18/Wp
- Install + DNO: £0.15-£0.30/Wp depending on roof type
- SEG floor: 3p/kWh (regulatory minimum)
- SEG ceiling: 15p/kWh (best 2026 fixed-tariff rate)
- Self-consumption rate: typical for large factory, supermarket, warehouse, hospital wing, university campus building, 5+ school MAT shared site load profile
250 kWp commercial solar · FAQs
How much does a 250 kWp commercial solar system cost in 2026?
At 2026 prices, a 250 kWp commercial solar PV system costs approximately £175,000 - £215,000 installed (excl. VAT). After 100% Full Expensing tax relief for a limited company at the 25% main CT rate, net cost is around £131,250 - £161,250.
What is the payback period for a 250 kWp commercial solar system?
With 45% self-consumption and SEG export tariffs of 3p-15p/kWh, a 250 kWp system typically pays back in 3.2-4.9 years post-tax (limited company at 25% CT). Higher tax rates (sole trader at 45%) compress payback further.
What size roof is needed for a 250 kWp system?
A 250 kWp system requires approximately 1,400 m² of unshaded roof area — around 550 modern 450W solar panels. Modern industrial portal-frame buildings, large warehouses and big-box retail typically accommodate this comfortably.
How much electricity will a 250 kWp system generate?
In the UK (average insolation), a 250 kWp system generates approximately 237,500 kWh per year. Self-consumption rate depends on your load profile — 45% is typical for large factory, supermarket, warehouse, hospital wing, university campus building, 5+ school MAT shared site.
Which grants apply to a 250 kWp system?
Best grant fit for this size: Full Expensing + SEG + REGO + (manufacturing) IETF candidacy + regional grant £10k-£30k. Always use the eligibility calculator for a personalised match.
Can I get finance for a 250 kWp solar system?
Yes — at this scale, asset finance / hire purchase is the most common route (5-7 year terms at 7-11% APR in 2026). For systems above 250kWp, operating lease and PPA are also viable. See finance routes.
Get a sized quote for your 250 kWp project
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