Commercial solar cost

Why £/kWp varies so much

Commercial solar pricing is usually discussed as a cost per kWp (kilowatt-peak of system size), but that single number hides a lot. Two proposals quoting a similar £/kWp can include very different scope — one might include full G99 grid connection costs, roof repairs and scaffolding; another might exclude all three and leave you to arrange and pay for them separately.

As a rough planning range (not a quote), UK commercial rooftop solar has recently sat broadly in the region of £550–£850 per kWp, ex-VAT, before battery storage. Broad UK commercial rooftop solar planning range as of general industry commentary. NOT verified against current installer quotes — treat as a placeholder pending founder market research.

What typically drives the price up or down

• System size — larger systems usually have a lower £/kWp due to fixed costs being spread further.
• Grid connection (G99) — DNO application, and especially any reinforcement work, can add significantly to cost and timeline.
• Roof condition — a roof needing repair, replacement, or with asbestos or fragile-roof considerations, adds cost and complexity.
• Access — scaffolding, cranes or cherry pickers for a difficult roof add cost that a simpler roof wouldn't need.
• Battery storage — a meaningful additional cost, typically quoted separately per kWh of capacity.
• Monitoring, warranties and O&M — whether ongoing monitoring, extended warranties and maintenance are included or sold separately.

Why the same £/kWp doesn't mean the same proposal

Before comparing headline prices, check what's actually included: is the DNO application fee in the price? Is scaffolding included? Is the export meter included? Is commissioning included? Two proposals at the same £/kWp can differ by thousands of pounds once exclusions are priced in.

Want a rough first estimate for your own site? Try our commercial solar calculator. Already have proposals in hand and want a proper comparison? Upload them for an independent review.