Commercial Solar Installation Costs 2026
The most detailed commercial solar cost breakdown in the UK — prices by system size, roof type, and region with 3 real itemised case studies. Updated May 2026.
£600–£1,000/kWp
Installed cost range
3–6 yr
Typical payback
100%
AIA first-year relief
25 yr
Panel warranty
Quick Answer
How much does commercial solar installation cost in the UK?
Commercial solar installation costs in the UK in 2026 range from £7,000 for a 10kW system to £700,000 for a 1MW installation. The typical cost per kWp is £650-£800 for systems over 50kW, rising to £900-£1,100/kWp for small 10-20kW systems. This includes panels, inverter, mounting, cabling, scaffolding, DNO application, monitoring and commissioning. Annual Investment Allowance (AIA) reduces the effective cost by 25% in Year 1 for corporation tax-paying businesses.
Commercial Solar Installation Costs 2026: Complete Breakdown
Commercial solar installation costs in 2026 range from £600 to £1,000+ per kWp depending on system size, roof type, location, and specification. This page provides the most detailed cost breakdown available — not just top-line numbers, but itemised costs for every component of a commercial solar installation, based on our quotations database from hundreds of projects completed in the past 24 months.
The Annual Investment Allowance provides 100% first-year tax relief on the full installation cost, reducing the effective net investment by 19–25% depending on your tax position. This is factored into all payback calculations below.
Cost by System Size (2026 Market Rates)
| System Size | Panels | Roof Area | Installed Cost | After AIA (25% CT) | Annual Saving | Payback |
|---|---|---|---|---|---|---|
| 20 kWp | ~51 panels | ~85 m² | £16,000–£22,000 | £12,000–£16,500 | ~£3,870/yr | 3.1–4.3 yr |
| 50 kWp | ~127 panels | ~210 m² | £34,000–£46,000 | £25,500–£34,500 | ~£9,680/yr | 2.6–3.6 yr |
| 100 kWp | ~253 panels | ~420 m² | £64,000–£90,000 | £48,000–£67,500 | ~£19,360/yr | 2.5–3.5 yr |
| 200 kWp | ~507 panels | ~840 m² | £124,000–£168,000 | £93,000–£126,000 | ~£38,720/yr | 2.4–3.3 yr |
| 500 kWp | ~1,267 panels | ~2,100 m² | £280,000–£380,000 | £210,000–£285,000 | ~£96,800/yr | 2.2–2.9 yr |
| 1,000 kWp | ~2,533 panels | ~4,200 m² | £530,000–£720,000 | £397,500–£540,000 | ~£193,600/yr | 2.1–2.8 yr |
Savings at 22p/kWh, 70% self-consumption, 880 kWh/kWp irradiance. After-AIA cost assumes 25% CT rate. Actual quotes vary by site.
What Makes Up the Installation Cost
Solar Panels (30–40% of cost)
Panels are the largest single cost component. Tier 1 monocrystalline PERC panels from manufacturers like JA Solar, Jinko Tiger Neo, or LONGi Hi-MO6 cost £0.18–£0.22/Wp ex-works in 2026. A 100kWp system requires 253 × 395Wp panels at a materials cost of approximately £23,000–£28,000. Premium bifacial panels add £0.03–£0.05/Wp but can improve yield by 5–12% on reflective surfaces like white EPDM membrane roofs. Non-Tier-1 budget panels cost £0.12–£0.16/Wp but come with weaker warranty support and higher degradation risk.
Inverters (15–20% of cost)
String inverters are the standard for rooftop commercial systems. SMA Sunny Tripower CORE2 (the industry benchmark) costs approximately £8,000–£12,000 per 100kWp of capacity at UK trade pricing. Sungrow SG110CX-P2 is a popular alternative at £6,000–£9,000/100kWp. Budget inverter brands from lesser-known Chinese manufacturers cost £3,000–£5,000/100kWp but lack the field service network and warranty terms of the established brands. Microinverters (Enphase IQ8) are used occasionally for shaded arrays or non-standard roof geometries and cost 40–60% more per kWp than string inverters.
Mounting and Racking (10–15% of cost)
Aluminium racking systems for profiled steel roofs (hook-and-clamp) cost approximately £50–£80/panel installed including fixings. Ballasted flat roof systems cost £70–£100/panel including ballast blocks and structural engineering sign-off. Ground-mounted racking adds £100–£180/panel due to foundation piling or concrete pads. All racking is aluminium alloy 6005-T5 or 6061-T6 with stainless steel fixings — no risk of galvanic corrosion when used with standard aluminium-frame solar panels.
Electrical Works (15–20% of cost)
Electrical works include: DC cabling from panels to inverter (solar-rated double-insulated 6mm² typically), AC cabling from inverter to grid connection point, protection devices (RCBO, surge protection, DC string fuses or optimisers), AC isolation switches, generation meter, and G99 protection relay settings. Electrical works scale approximately linearly with system size but have a fixed mobilisation element of £1,500–£3,000 per site regardless of size.
Scaffold and Access (5–10% of cost)
Scaffold access is required for pitched roofs above 3.5m eaves height. Edge protection, working platforms, and materials hoists are all required under CDM regulations. A standard edge-protection scaffold for a 400m² pitched roof costs approximately £2,500–£4,500 erected and struck. Flat-roof ballasted systems rarely require scaffold — a Mobile Elevating Work Platform (MEWP) at £350–£600/day is often sufficient for smaller flat-roof projects.
DNO Application and G99 (3–5% of cost)
The DNO G99 application fee (for systems above 50kWp) is typically nil for urban commercial sites. However, if the connection offer requires network reinforcement (new cable, transformer upgrade), costs of £10,000–£150,000+ may be levied. These are exceptional — most commercial premises already have adequate three-phase capacity for systems up to 250kWp. We assess DNO connection risk at the survey stage and flag any potential connection costs before contract.
Cost by Roof Type
| Roof Type | Cost Modifier | Why | Notes |
|---|---|---|---|
| Trapezoidal steel | Baseline (0%) | Fast installation, no penetrations | Best value roof type |
| IBR profiled steel | +3–5% | Less common fittings | Standard procedure |
| Flat EPDM / felt | +8–15% | Ballast system, structural survey | No penetrations |
| Flat concrete/GRC | +10–18% | Ballast + heavier base plate design | Survey essential |
| Asbestos cement (ACM) | +30–60% | ACM removal, new cladding, disposal | Licensed contractor required |
| Timber (heritage) | +20–35% | Structural engineer, bespoke fixings | Listed building check |
| Standing seam metal | +5–10% | Specialist S-5! clamps | No penetrations |
| Clay/concrete tiles | +15–25% | Individual tile lifts, penetrations | Survey for load capacity |
Modifiers applied to the baseline 100kWp installation cost of £64,000–£90,000.
Regional Cost Variations
| Region | Labour Modifier | Representative Cities | Notes |
|---|---|---|---|
| South East / London | +12–18% | London, Brighton, Oxford, Reading | Higher contractor rates |
| South West | +3–6% | Bristol, Exeter, Plymouth | Near baseline |
| Midlands (East + West) | Baseline | Birmingham, Nottingham, Leicester | Competitive market |
| North West | +2–5% | Manchester, Liverpool, Preston | Active solar market |
| North East / Yorkshire | +0–3% | Leeds, Sheffield, Newcastle | Competitive |
| Scotland | +5–10% | Glasgow, Edinburgh, Aberdeen | Higher mobilisation |
| Wales | +3–7% | Cardiff, Swansea, Newport | BES grant offsets |
| Northern Ireland | +8–15% | Belfast, Derry | Ferry + smaller market |
Three Real Cost Case Studies
Case Study 1: 50kWp Food Manufacturer, West Midlands — £37,500
A food manufacturer in Wolverhampton with a 500m² trapezoidal steel roof installed 50kWp in October 2024. Itemised costs:
| Item | Cost |
|---|---|
| 127 × 395Wp JA Solar Mono PERC panels | £11,430 |
| 1 × 50kW SMA Sunny Tripower CORE2 inverter | £4,200 |
| Mounting (hook-and-clamp racking, fixings) | £5,080 |
| DC/AC cabling, protection devices, meter | £6,200 |
| Scaffold (edge protection, 3 days) | £2,100 |
| G99 application and DNO liaison | £800 |
| Design, survey, MCS certification | £3,400 |
| Project management and commissioning | £2,800 |
| Monitoring hardware (SMA Sunny Portal) | £1,490 |
| Total installed | £37,500 (£750/kWp) |
Case Study 2: 200kWp Logistics Hub, East Midlands — £148,000
A logistics operator in Northampton installed 200kWp on a flat EPDM-membrane warehouse roof in January 2025. Ballasted east/west arrays were used — no penetrations of the roof membrane.
| Item | Cost |
|---|---|
| 506 × 395Wp Jinko Tiger Neo bifacial panels | £44,600 |
| 2 × 100kW Sungrow SG100CX-P2 inverters | £15,200 |
| East/west ballasted aluminium frames + ballast | £24,200 |
| DC/AC cabling, RCBO/SPD protection, meter | £19,800 |
| Structural engineering sign-off (ballast loads) | £2,400 |
| MEWP access (2 days), materials lift | £1,600 |
| G99 application + NGED liaison | £1,200 |
| Design, survey, project management, MCS cert | £8,800 |
| Monitoring (Sungrow iSolarCloud) | included |
| Commissioning and final sign-off | £2,200 |
| Subtotal materials and labour | £120,000 |
| DNO connection reinforcement (minor feeder work) | £18,000 |
| Contingency (5%) | £6,000 |
| Total installed | £148,000 (£740/kWp) |
Case Study 3: 350kWp School Campus, Yorkshire — £245,000
A secondary school in Leeds installed 350kWp across three building rooftops in April 2025, using Salix Finance 0% loans to fund 80% of the cost. The project included asbestos cement panel replacement on one building roof.
- Buildings 1 and 2 (clean steel roofs): 250kWp at £680/kWp = £170,000
- Building 3 (ACM roof replacement required): 100kWp at £950/kWp = £95,000
- DNO G99 to NGED Yorkshire: nil connection cost
- Salix Finance loan: £196,000 at 0% over 7 years repaid from savings
- Net school outlay in year 1: £49,000
Get a Commercial Solar Installation Quote
We survey, design, and install commercial solar across the UK. All quotes are itemised — no hidden DNO or MCS costs. Free site survey.
Request Itemised QuoteHow to Reduce Installation Costs
- Choose a straightforward roof type — trapezoidal steel is 20–40% cheaper per kWp than ACM replacement or flat ballasted
- Size correctly — don't over-specify. A well-sized 150kWp system at £700/kWp beats a padded 200kWp system at £800/kWp
- Get 3+ competitive quotes — the commercial solar market is competitive; 15–25% price variation between comparable contractors is common
- Use AIA — the 100% first-year tax relief effectively reduces your net cost by 19–25%
- Apply for IETF (large manufacturers) or Salix Finance (public sector) — these can fund 20–100% of the cost at nil or zero interest
- Combine with other works — if the roof needs a re-cover or ACM replacement anyway, bundling with solar reduces the combined project mobilisation cost
Frequently Asked Questions
What does a 100kWp commercial solar installation cost in 2026?
A 100kWp commercial solar installation in 2026 costs approximately £70,000–£90,000 fully installed, including design, materials, DNO G99 application, scaffolding, electrical installation, MCS certification, and commissioning. The wide range reflects: roof type complexity (profiled steel is cheapest; asbestos cement replacement adds £15,000–£30,000), location (London and South East carry a 10–15% labour premium), and specification choices (Tier 1 mono PERC vs bifacial panels, SMA vs budget inverters). Use our pricing tables below to estimate for your specific system size.
What is included in the installation cost?
A fully installed commercial solar quote should include: (1) detailed site survey and structural assessment; (2) system design and electrical schematic; (3) planning/PD assessment and application if required; (4) DNO G99 application and liaison (for systems above 11kWp three-phase); (5) scaffold or MEWP access; (6) panels, inverters, racking, cabling, and switchgear supply; (7) installation by MCS-certified electricians; (8) commissioning and G99 witness testing; (9) MCS certificate; (10) system handover and monitoring setup. Any quote that omits DNO application fees or MCS certification should be treated with caution.
Why do some quotes seem significantly cheaper than others?
Commercial solar quotes vary for several legitimate reasons: panel tier (Tier 1 JA Solar vs non-Tier brands), inverter brand (SMA/Sungrow premium vs budget Chinese inverters), DNO application included or excluded, MCS certification included or excluded, and scaffold access method (tower scaffold vs MEWP). A cheaper quote that excludes DNO application, uses non-Tier-1 panels, and specifies a budget inverter brand may save £5,000–£15,000 upfront but cost significantly more over 25 years in warranty disputes, lower yield, and inferior technical support. Always compare on a like-for-like basis.
How do roof type and access affect installation cost?
Roof type is the single biggest variable in commercial solar installation cost after system size. A clean trapezoidal steel profile with good scaffold access may cost £600–£700/kWp for a 100kWp system. The same system on an asbestos cement roof requiring removal and replacement with steel cladding will cost £900–£1,200/kWp (including ACM disposal under Control of Asbestos Regulations). Flat EPDM roofs needing ballasted arrays are in the middle at £700–£850/kWp. North-light sawtooth roofs with limited access add £80–£120/kWp to scaffold costs.
Does the size of the system affect the price per kWp?
Yes — commercial solar benefits from significant economies of scale. A 20kWp system might cost £900–£1,100/kWp, while a 200kWp system on a similar roof type will typically cost £650–£800/kWp. The reductions come from: fixed design costs spread over a larger system; bulk panel and inverter procurement discounts; scaffold setup cost amortised over more panels; and reduced mobilisation costs per kWp. Systems above 500kWp can be procured at £500–£650/kWp in competitive tender situations.
Are there ongoing costs after installation?
Yes. Budget for: (1) annual O&M service: £300–£700/year for a 100kWp system (inspections, cleaning, thermal imaging, electrical testing); (2) inverter maintenance: inverters have 10-year standard warranties (extendable to 20 years at contract), after which repairs or replacement cost £800–£3,500 per unit; (3) monitoring subscription: most platforms are included free in the first 10 years, then £100–£300/year; (4) panel replacements: individual panel faults are rare (typically covered by 25-year product warranty); budget £200–£400/panel if out-of-warranty replacement is needed. Total ongoing cost is typically £400–£900/year for a 100kWp system.
How does VAT work on commercial solar installations?
Commercial solar installations are subject to 20% VAT (standard rate). This applies to the full installed cost including panels, inverters, racking, labour, and professional fees. VAT-registered businesses can reclaim the 20% VAT on installation as input tax — effectively making the commercial solar purchase tax-neutral on the VAT element. The Annual Investment Allowance then applies to the VAT-exclusive capital cost, providing 100% first-year Corporation Tax relief. Non-VAT-registered businesses (sole traders below the threshold, non-profit organisations) cannot reclaim VAT — this should be factored into the net cost calculation.
Can I use the Annual Investment Allowance on the full installation cost?
Yes. The Annual Investment Allowance (AIA) applies to the full capital cost of commercial solar installation (VAT-exclusive for VAT-registered businesses). The current AIA limit is £1,000,000 per year — well above any commercial solar installation cost. The AIA deduction reduces your taxable profit by the full installation cost in year one. At the current 25% Corporation Tax rate, a £100,000 installation generates a tax saving of £25,000 in year one — reducing the effective after-tax cost to £75,000. Sole traders and partnerships paying income tax at 40–45% benefit even more proportionally.
Get a detailed installation cost breakdown for your premises
Free site survey includes itemised cost quote — panels, labour, DNO application, scaffolding, monitoring — plus AIA tax calculation and 25-year ROI model. Response within 2 working days.
Get Free Installation QuoteCommercial Solar Installation Cost Breakdown: Labour vs Equipment
Understanding where your commercial solar budget is spent helps you evaluate quotes and identify where savings are possible. Here is a typical cost breakdown for a 100kWp roof-mounted installation in 2026:
| Cost Component | % of Total | Cost (100kWp) | Notes |
|---|---|---|---|
| Solar panels | 40-45% | £27,000-£38,000 | Tier 1 brands (Jinko, JA Solar, LONGi) |
| Inverter(s) | 12-18% | £8,000-£15,000 | SolarEdge, SMA, Huawei, Sungrow |
| Mounting system | 8-12% | £5,000-£10,000 | Ballasted flat or pitched rail system |
| Cabling & electrics | 8-10% | £5,000-£8,500 | DC cabling, AC cabling, protection |
| Installation labour | 10-15% | £7,000-£12,750 | Typically 4-6 days (3-person team) |
| Scaffolding | 3-6% | £2,000-£5,000 | Varies by roof height and access |
| DNO application (G99) | 2-4% | £1,500-£3,500 | G99 application fee + connection costs |
| Monitoring system | 1-2% | £700-£1,700 | Cloud monitoring + data logger |
| Total (100kWp) | 100% | £63,000-£85,000 | £630-£850/kWp. 0% VAT. |
After AIA tax relief: A 25% Corporation Tax payer claims back 25% of the full installation cost in Year 1. For a £75,000 100kWp installation, the AIA saving is £18,750 — reducing the effective net cost to £56,250 and improving payback from 3.0 years to 2.25 years.