1MW commercial solar PV cost in the UK (2026)
At 2026 prices, a 1 MWp commercial solar PV system costs £600,000 - £750,000 installed (excl. VAT). After 100% Full Expensing for limited companies, net cost is around 25% lower. Typical post-tax payback: 3.3-7.4 years.
1 MWp cost summary
| System size | 1 MWp |
| Installed cost range (2026, excl. VAT) | £600,000 - £750,000 |
| £ per Wp | £0.60 - £0.75 |
| Number of panels (450W modules) | ~2,200 |
| Roof area required | ~5,500 m² |
| Annual generation (UK avg) | 950,000 kWh |
| Best fit for | big-box warehouse, large industrial site, university campus, multi-acre ground-mount |
| Best grant stack | Full Expensing (uncapped) + IETF (industry) or PSDS (public) + REGO + behind-the-meter PPA or wholesale entry |
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) | £675,000 |
| 100% Full Expensing tax saving (25% CT) | -£168,750 |
| Net effective cost | £506,250 |
| Annual self-consumption (25%) | 237,500 kWh saving £47,500/year |
| Annual SEG export (75%) | 712,500 kWh earning £21,375 - £106,875/year |
| Total year-1 savings/revenue | £68,875 - £154,375 |
| Post-tax payback | 3.3 - 7.4 years |
Typical roof & site requirements for 1 MWp
- Unshaded roof area: ~5,500 m² needed for 2,200 × 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 1 MWp
Recommended grant stack
Full Expensing (uncapped) + IETF (industry) or PSDS (public) + REGO + behind-the-meter PPA or wholesale entry
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 big-box warehouse, large industrial site, university campus, multi-acre ground-mount load profile
1 MWp commercial solar · FAQs
How much does a 1 MWp commercial solar system cost in 2026?
At 2026 prices, a 1 MWp commercial solar PV system costs approximately £600,000 - £750,000 installed (excl. VAT). After 100% Full Expensing tax relief for a limited company at the 25% main CT rate, net cost is around £450,000 - £562,500.
What is the payback period for a 1 MWp commercial solar system?
With 25% self-consumption and SEG export tariffs of 3p-15p/kWh, a 1 MWp system typically pays back in 3.3-7.4 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 1 MWp system?
A 1 MWp system requires approximately 5,500 m² of unshaded roof area — around 2,200 modern 450W solar panels. Modern industrial portal-frame buildings, large warehouses and big-box retail typically accommodate this comfortably.
How much electricity will a 1 MWp system generate?
In the UK (average insolation), a 1 MWp system generates approximately 950,000 kWh per year. Self-consumption rate depends on your load profile — 25% is typical for big-box warehouse, large industrial site, university campus, multi-acre ground-mount.
Which grants apply to a 1 MWp system?
Best grant fit for this size: Full Expensing (uncapped) + IETF (industry) or PSDS (public) + REGO + behind-the-meter PPA or wholesale entry. Always use the eligibility calculator for a personalised match.
Can I get finance for a 1 MWp 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 1 MWp project
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