Commercial solar panel costs at a glance
The cost of a commercial solar installation in the UK depends on system size, roof type, panel specification and grid-connection requirements. As a general guide, fully-installed prices in 2026 sit between £700 and £1,100 per kWp. Larger systems benefit from economies of scale: a 100kWp system typically lands around £850/kWp, while smaller 10–30kWp systems tend to sit closer to £1,000–£1,200/kWp because fixed costs are spread over fewer panels.
Most commercial buyers also factor in the Annual Investment Allowance, which lets businesses deduct the full cost from taxable profits in year one (up to £1 million). For a business paying 25% corporation tax, that takes the net cost of an £85,000 system down to roughly £63,750. We cover this in detail further down.
What you'll pay by system size
| System size | Approx. panel count | Roof area needed | Installed cost | Cost per kWp | Annual generation |
|---|---|---|---|---|---|
| 10 kWp | 22–25 panels | ~55 m² | £10,000–£12,000 | £1,000–£1,200 | ~9,000 kWh/yr |
| 20 kWp | 45–50 panels | ~110 m² | £18,000–£22,000 | £900–£1,100 | ~18,000 kWh/yr |
| 50 kWp | 110–125 panels | ~280 m² | £42,500–£55,000 | £850–£1,100 | ~45,000 kWh/yr |
| 100 kWp | 220–250 panels | ~550 m² | £70,000–£95,000 | £700–£950 | ~90,000 kWh/yr |
| 250 kWp | 550–625 panels | ~1,400 m² | £175,000–£220,000 | £700–£880 | ~225,000 kWh/yr |
| 500 kWp+ | 1,100+ panels | ~2,800 m²+ | £350,000+ | £680–£800 | ~450,000 kWh/yr |
Figures are inclusive of panels, inverters, mounting, cabling, scaffolding, grid connection and installation labour. VAT is charged at 20% and is recoverable for VAT-registered businesses.
What's in the price?
A well-itemised commercial solar quote breaks down into three cost areas: equipment, installation labour, and grid connection. The proportions are remarkably consistent across system sizes:
| Cost component | Share of total | Notes |
|---|---|---|
| Solar panels | 35–45% | Standard commercial panels are 400–600W. Higher-efficiency panels cost more but produce more from the same roof area. |
| Inverter(s) | 10–15% | String inverters are cheapest; micro-inverters and optimisers cost more but perform better with shading. |
| Mounting, cabling, isolators, metering | 8–12% | Flat-roof ballast systems are cheaper than pitched-roof rail mounting. |
| Installation labour & project management | 25–35% | Includes scaffolding, electrical work, commissioning and DNO paperwork. |
| Grid connection (G98 or G99) | 0–10% | Free for systems under 16A per phase. Larger systems require a G99 application and may incur reinforcement costs. |
Cost by sector
Sector dictates the typical system size and roof type, which in turn drive the installed cost and payback. The figures below are indicative starting points; the only way to get an accurate price is a site survey.
| Sector | Typical system size | Indicative installed cost | Typical payback |
|---|---|---|---|
| Hotels & hospitality | 30–100 kWp | £28,000–£90,000 | 4–6 years |
| Warehouses & distribution | 100–500 kWp | £75,000–£380,000 | 4–6 years |
| Manufacturing | 100–500 kWp | £75,000–£380,000 | 3–5 years |
| Farms & agriculture | 50–250 kWp | £45,000–£200,000 | 4–6 years |
| Schools & academies | 30–150 kWp | £28,000–£130,000 | 5–7 years |
| NHS & healthcare | 50–250 kWp | £45,000–£200,000 | 5–7 years |
| Office buildings | 20–100 kWp | £18,000–£90,000 | 5–7 years |
| Retail & supermarkets | 30–200 kWp | £28,000–£160,000 | 4–6 years |
| Leisure & sports | 30–100 kWp | £28,000–£90,000 | 4–6 years |
| Logistics & haulage | 50–250 kWp | £45,000–£200,000 | 4–6 years |
What affects the price?
Roof type
Flat roofs using ballast-mounted systems are the cheapest to install. Pitched roofs require rail mounting and add cost. Fragile substrates such as old asbestos or weathered felt may need reinforcement or replacement first, which can add £5,000–£25,000 depending on roof size.
Scaffolding and access
Multi-storey buildings, busy car parks, restricted access points and live operational sites all add scaffolding and labour cost. Single-storey industrial units with clear access are the most cost-effective.
Panel specification
Standard monocrystalline panels (400–450W) deliver the best cost-per-watt. High-efficiency 500W+ panels cost more per panel but generate more from the same roof area, which often pays back when roof space is the limiting factor.
Inverter type
String inverters are the lowest-cost option and suit unshaded roofs. Where any panels will be shaded for part of the day (chimneys, neighbouring buildings, vents) micro-inverters or DC optimisers recover more output but add roughly 15–25% to inverter cost.
Grid connection (G98 vs G99)
Systems generating up to 16A per phase (~3.68 kWp single phase or ~11 kWp three phase) fall under G98 and connect quickly with a notification to your Distribution Network Operator. Anything larger requires a G99 application, which takes 4–12 weeks and may incur reinforcement costs if your local network lacks capacity. Most commercial installs above 11 kWp will be G99.
Tax relief and finance
UK tax rules can reduce the effective cost of a commercial solar system by 19–25% in year one alone. The major reliefs:
Annual Investment Allowance (AIA)
The AIA lets businesses deduct the full cost of qualifying plant and machinery (which includes solar panels) from taxable profits in the year of purchase, up to £1 million per year. For a business on the 25% corporation tax rate, an £85,000 system generates a tax deduction worth £21,250 in year one. Full tax benefits guide.
Full expensing
Incorporated companies (not sole traders or partnerships) can alternatively claim 100% full expensing on qualifying new plant and machinery purchased from April 2023 onwards. Unlike the AIA, full expensing has no annual cap, so it is the better option for very large installations or businesses that have already used their AIA.
Business rates exemption
Rooftop solar installations added to commercial properties between April 2023 and March 2035 are exempt from business rates. This removes what would otherwise be an ongoing annual cost that erodes your returns.
VAT treatment
VAT on commercial solar installations is charged at 20% but is recoverable for VAT-registered businesses using the system for business purposes. In effect that brings the headline price down by 20% for most commercial buyers.
Three ways to finance the system
| Option | Upfront | Tax benefits | Best for |
|---|---|---|---|
| Outright purchase | Full cost | AIA + full expensing + all SEG income | Businesses with available capital and taxable profits |
| Asset finance / lease | Low or none | Lease payments deductible as operating expense | Businesses preserving cash, but accept 10–30% lower lifetime returns |
| Power Purchase Agreement (PPA) | None | Lower (you don't own the asset) | Sites where the operator wants zero capex and a fixed unit rate, accepting reduced ownership benefits |
For a side-by-side comparison see our lease vs buy guide.
Ongoing costs after installation
Commercial solar systems are low-maintenance but not zero-cost. Budget for:
- Operations & maintenance: £7–15 per kWp per year. For a 100 kWp system that is roughly £700–£1,500 annually, covering remote monitoring, an annual inspection, panel cleaning and emergency callouts. Full maintenance cost breakdown.
- Inverter replacement: string inverters typically last 10–15 years, so plan for at least one replacement during the system's 25–30 year life. Micro-inverters and optimisers carry 20–25 year warranties.
- Panel degradation: modern panels lose 0.25–0.5% of output per year. After 25 years a system still produces ~85–90% of its original output.
Reducing the cost with grants
Several grant schemes can reduce the net capital outlay further. The Public Sector Decarbonisation Scheme (Salix) is the largest single source for schools, NHS sites and local authorities. The Rural England Prosperity Fund (REAP) and UK Shared Prosperity Fund (UKSPF) cover other commercial sites. See our commercial solar grants page and 2026 grants & funding guide for the full picture.
Frequently asked questions
How much do commercial solar panels cost per kWp in the UK?
In 2026, fully-installed commercial solar systems in the UK cost between £700 and £1,100 per kWp. Larger systems (100 kWp+) sit at the lower end of that range; smaller systems (10–30 kWp) cost more per kWp because fixed costs are spread over fewer panels.
What is the typical payback period for commercial solar?
Most well-sized commercial solar installations pay back in 4 to 6 years. Sectors with high daytime electricity use (manufacturing, logistics, supermarkets) often achieve 3–5 year payback. Sectors with lower self-consumption (offices, schools) typically see 5–7 years.
Do I need MCS-accredited installers?
For systems up to 50 kW, MCS certification is effectively required to claim the Smart Export Guarantee. For larger commercial installations, MCS is not legally required but is widely treated as the quality benchmark. nu.energy only matches enquiries with MCS-accredited installers.
Can I claim tax relief on a commercial solar installation?
Yes. The Annual Investment Allowance lets you deduct the full cost (up to £1 million) from taxable profits in year one. Limited companies can alternatively claim 100% full expensing with no annual cap. VAT is recoverable for VAT-registered businesses, and rooftop installations added between April 2023 and March 2035 are exempt from business rates.
What grants are available for commercial solar in 2026?
The Public Sector Decarbonisation Scheme (administered by Salix) covers schools, NHS sites and local authorities. The Rural England Prosperity Fund (REAP) and UK Shared Prosperity Fund (UKSPF) cover other commercial sites. Combined with tax relief, grants can reduce net cost by 40–60% in eligible cases.
Is there a difference between G98 and G99 grid connection?
Yes. G98 covers systems up to 16A per phase (~3.68 kWp single phase, ~11 kWp three phase) and is a notification only. G99 covers anything larger and requires a formal application to your Distribution Network Operator, taking 4–12 weeks. Most commercial installations are G99.
Do I need planning permission for a commercial solar installation?
Most rooftop commercial solar installations fall under permitted development rights and do not need planning permission. Listed buildings, conservation areas, and ground-mounted systems above 1 MW typically require planning permission. A reputable installer will confirm the planning position before quoting.
How long do commercial solar panels last?
Commercial solar panels are designed for a 25–30 year working life. Modern panels lose 0.25–0.5% of output per year, so after 25 years a system still produces around 85–90% of its original output. Inverters typically need replacing once during this period.
- Commercial Solar Panel Costs UK: 2026 Price Breakdown
- Commercial Solar Tax Benefits: Complete UK Business Guide
- Commercial Solar: Lease vs Buy Comparison
- Commercial Solar ROI & Payback Calculator Guide
- Commercial Solar Panel Maintenance Costs Guide
- UK Commercial Solar Grants & Funding 2026
- UK Commercial Solar Procurement Process Guide
Get an accurate quote
Every site is different. The only way to get an accurate price for your building is a site survey. nu.energy connects UK businesses with up to three MCS-accredited commercial solar installers for free, no-obligation quotes, with a typical 24-hour response.
