75 kWp commercial solar PV cost in the UK (2026)
At 2026 prices, a 75 kWp commercial solar PV system costs £62,500 - £78,000 installed (excl. VAT). Typical post-tax payback: 3.3-4.1 years.
75 kWp cost summary
| System size | 75 kWp |
| Installed cost (2026, excl. VAT) | £62,500 - £78,000 |
| £/Wp | £0.83 - £1.04 |
| Number of panels (450W) | ~165 |
| Roof area required | ~420 m² |
| Annual generation (UK avg) | 71,250 kWh |
| Best fit for | medium office, hotel, garden centre, dental practice |
| Best grant stack | AIA / Full Expensing + SEG + regional grant £3k-£12k |
Year-1 maths breakdown
| Gross capex (mid) | £70,250 |
| 100% Full Expensing tax saving (25% CT) | -£17,562 |
| Net effective cost | £52,688 |
| Annual self-consumption (62%) | 44,175 kWh saving £11,927/year |
| Annual SEG export (38%) | 27,075 kWh earning £812 - £4,061/year |
| Total year-1 savings/revenue | £12,740 - £15,988 |
| Post-tax payback | 3.3 - 4.1 years |
75 kWp commercial solar · FAQs
How much does a 75 kWp commercial solar system cost in 2026?
At 2026 prices, a 75 kWp commercial solar PV system costs approximately £62,500 - £78,000 installed (excl. VAT). After 100% Full Expensing tax relief for a limited company at the 25% main CT rate, net cost is around £46,875 - £58,500.
What is the payback period for a 75 kWp commercial solar system?
With 62% self-consumption and SEG export tariffs of 3p-15p/kWh, a 75 kWp system typically pays back in 3.3-4.1 years post-tax.
What size roof is needed for a 75 kWp system?
A 75 kWp system requires approximately 420 m² of unshaded roof area — around 165 450W panels.
How much electricity will a 75 kWp system generate?
A 75 kWp system generates approximately 71,250 kWh per year in UK conditions. Best fit for medium office, hotel, garden centre, dental practice.
Which grants apply to a 75 kWp system?
Best grant fit: AIA / Full Expensing + SEG + regional grant £3k-£12k. Always use the eligibility calculator for a personalised match.
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