What do commercial solar panels cost in 2026?
The cost of commercial solar panels in the UK depends on system size, panel type, roof complexity and inverter specification. As a general guide:
- Small systems (10–30 kWp): £12,000–£35,000
- Medium systems (30–100 kWp): £30,000–£90,000
- Large systems (100–250 kWp): £80,000–£200,000
- Very large systems (250+ kWp): £180,000+
The cost per kWp decreases with scale. Small systems typically cost £1,000–£1,200 per kWp installed. Larger systems (100+ kWp) can come in at £700–£850 per kWp.
What affects the price?
Roof type: Flat roofs using ballast-mounted systems are generally cheaper than pitched roofs requiring rail mounting. Fragile roofs (asbestos, older felt) may need reinforcement or replacement first, adding cost.
Scaffolding and access: Multi-storey buildings or sites with restricted access increase installation costs. Ground-floor flat roofs are the most cost-effective to install on.
Panel specification: Standard monocrystalline panels (400–450W) are the most cost-effective. High-efficiency panels (500W+) cost more but produce more from the same roof area.
Inverter type: String inverters are cheaper. Micro-inverters and power optimisers cost more but perform better where shading is an issue.
Grid connection: Systems up to 16A per phase (approximately 3.68 kWp single phase or 11 kWp three phase) fall under G98 and connect quickly. Larger systems require a G99 application to the local Distribution Network Operator (DNO), which can take 4–12 weeks and may incur costs if grid reinforcement is needed.
Tax relief and cost reduction
The Annual Investment Allowance (AIA) allows businesses to deduct the full cost of solar from taxable profits in the year of purchase, up to £1 million. For a business paying 25% corporation tax, a £100,000 solar system effectively costs £75,000 after tax relief.
When combined with grant funding (REAP, UKSPF, Salix), the net cost can drop by 40–60%.
Getting an accurate quote
Every building is different. The only way to get an accurate price is to request quotes from qualified installers who can assess your site. nu.energy connects you with up to 3 MCS-accredited installers for free, no-obligation quotes.