Quick Answer: Factory Solar Costs in 2026
2026 Price Summary
Factory solar panels in the UK cost between £700 and £950 per kilowatt-peak (kWp) installed in 2026, including panels, inverters, mounting, cabling and labour. A typical 100kW system for a small factory costs £70,000–£95,000. A 300kW system for a medium manufacturer costs £195,000–£270,000. A 1MW system for a large industrial site costs £620,000–£850,000. Annual electricity savings of 25–32p per kWh generated typically deliver a 3–5 year payback period.
These figures represent fully installed, turnkey costs from reputable MCS-certified UK installers. They include everything needed to commission a grid-connected system under G99 regulations. They do not include battery storage, which adds £200–£400/kWh of battery capacity if required.
Cost by System Size: 50kW to 2MW
The table below shows typical installed cost ranges for factory solar systems in 2026. Costs per kWp fall as system size increases, reflecting bulk purchasing, reduced relative labour costs, and more competitive tendering at larger scales.
| System Size | Total Cost Range | Cost per kWp | Typical Annual Output | Annual Saving (at 30p/kWh) |
|---|---|---|---|---|
| 50kW | £42,500–£52,500 | £850–£1,050 | 47,500 kWh | £14,250 |
| 100kW | £70,000–£95,000 | £700–£950 | 95,000 kWh | £28,500 |
| 200kW | £134,000–£180,000 | £670–£900 | 190,000 kWh | £57,000 |
| 300kW | £195,000–£270,000 | £650–£900 | 285,000 kWh | £85,500 |
| 500kW | £312,500–£425,000 | £625–£850 | 475,000 kWh | £142,500 |
| 750kW | £450,000–£622,500 | £600–£830 | 712,500 kWh | £213,750 |
| 1MW (1,000kW) | £620,000–£850,000 | £620–£850 | 950,000 kWh | £285,000 |
| 2MW (2,000kW) | £1,180,000–£1,600,000 | £590–£800 | 1,900,000 kWh | £570,000 |
Note: Annual output assumes 950 kWh/kWp/year (UK average for south-facing roof at 15–30 degree pitch). Savings calculated at 30p/kWh blended electricity rate. Actual figures vary by location, consumption profile and export.
What Is Included in the Installation Price?
A fully installed factory solar system price should cover all of the following components. If a quote excludes any of these, request a revised quote or a separate line-item cost before comparing.
| Component | % of Total Cost | Notes |
|---|---|---|
| Solar panels (modules) | 35–40% | Typically 400W–450W monocrystalline panels |
| Inverters | 15–20% | String or central inverters; Sungrow, Fronius, SMA, Huawei common brands |
| Mounting and racking | 10–15% | Ballasted (flat roof) or penetrating (pitched roof) systems |
| Cabling and electrical BOS | 8–12% | DC and AC cabling, isolators, protection equipment |
| Installation labour | 20–25% | Scaffold, roof access, installation team, commissioning |
| G99/DNO application | 2–5% | Grid connection application fees and engineering study (systems over 50kW) |
| Monitoring system | 1–3% | Online portal for real-time generation and performance data |
| Design, surveys, project management | 3–5% | Structural surveys, CAD design, planning preparation if needed |
What Affects the Price?
Two factories of the same size can receive quotes that differ by 20–30%. Understanding the key pricing variables helps you assess whether a quote is genuinely competitive or simply cheap because corners are being cut.
1. Roof Type and Condition
Flat industrial roofs (common on warehouses and factories) are generally the most cost-effective because ballasted mounting systems require no roof penetrations. Pitched or profiled metal roofs (common on older factories) use hook-and-rail systems that are slightly more labour-intensive. Asbestos-containing roofs require specialist handling and can add significant cost — or may prevent installation entirely until the roof is replaced.
2. System Size and Economies of Scale
The per-kWp cost falls meaningfully as system size increases. A 50kW system costs £850–£1,050/kWp; a 500kW system costs £625–£850/kWp. This is because fixed costs (design, surveys, DNO application, mobilisation) are spread across more panels, and bulk purchasing improves panel and inverter pricing.
3. Panel Brand and Efficiency
Premium panel brands (Sunpower, REC, Q CELLS, Longi Hi-MO) cost 10–20% more than mainstream Chinese panels (JA Solar, Trina, Canadian Solar) but offer higher efficiency (22–24% vs 20–22%) and stronger product warranties. For space-constrained roofs where maximising output per m² matters, premium panels can be worth the premium. For large open roofs, mainstream panels typically offer the best cost-to-performance ratio.
4. Inverter Type
String inverters (multiple units, each managing a string of panels) are the standard for most industrial systems and offer good value. Central inverters (one large unit) suit very large installations but require more complex maintenance. Microinverters (one per panel) provide the best shade tolerance and monitoring granularity but cost 30–50% more than string inverter systems and are rarely used on large factory installations.
5. DNO Connection Complexity
Systems over 50kW require a G99 application to your Distribution Network Operator (DNO). In most cases this is straightforward and costs £2,000–£8,000. However, if your local network has capacity constraints, the DNO may require a grid reinforcement contribution that can add £10,000–£80,000 to the project cost. Always ask your installer to check DNO capacity before committing to a project.
6. Scaffolding and Roof Access
Factory roofs can be 10–15 metres high, requiring substantial scaffold. On a large flat roof, mobile elevating work platforms (MEWPs) are often more cost-effective. The site-specific access requirements can vary the labour cost significantly.
Regional Cost Variation Across the UK
Labour costs and competition among solar installers vary by region, creating modest price differences across the UK.
| Region | Cost vs National Average | Notes |
|---|---|---|
| London and South East | +5–10% | Higher labour costs; better solar irradiation partly offsets higher installation cost |
| South West and East Anglia | Base rate to +5% | Good solar resource; competitive installer market in some areas |
| Midlands | Base rate | Strong competition; dense concentration of industrial solar installers |
| North West and North East | Base rate to -3% | Slightly lower labour costs; Slightly lower solar irradiation (950 vs 1,050 kWh/kWp in South) |
| Yorkshire and Humber | Base rate to -3% | Good value region; active manufacturing solar market |
| Scotland | Base rate to +5% | Fewer specialist installers in some areas; lower irradiation (850–900 kWh/kWp) reduces returns |
| Wales | Base rate | Welsh Government often has additional grant programmes; check Business Wales for current funding |
Hidden Costs to Watch For
Some costs are routinely excluded from initial quotes. Make sure you understand the full project cost before signing a contract.
G99 DNO Application Fees
Systems over 50kW require a formal G99 application. DNO engineering study fees range from £1,500 to £6,000 and are sometimes excluded from quotes. If the DNO requires network reinforcement, costs can be substantially higher.
Scaffolding on Complex Roofs
Specialist access on tall or awkwardly shaped roofs may require bespoke scaffolding solutions. This can add £5,000–£25,000 on large or complex sites. Always ensure the survey includes a scaffolding cost assessment.
Electrical Distribution Board Upgrades
If your factory's main electrical distribution board is near capacity, it may need upgrading before a solar system can be connected. This can cost £3,000–£15,000 depending on the extent of work required.
Roof Repairs Before Installation
Installers will not install solar on a roof that requires imminent repair — they would need to be removed during any subsequent roof work. A structural survey may reveal that roof repairs costing £5,000–£50,000+ are needed before installation can proceed.
Planning Application Fees
Most factory solar installations qualify as Permitted Development and do not require planning permission. However, buildings in conservation areas, listed buildings, or where roof-mounted panels exceed certain size thresholds may require a planning application (£462 for England in 2026) plus architect and planning consultant fees of £1,500–£5,000.
Annual Maintenance Costs
Though not an installation cost, budget for annual O&M costs of £1,500–£5,000/year (depending on system size) covering inverter health checks, panel cleaning, monitoring subscription and periodic electrical inspections.
Annual Investment Allowance: Reducing Your Effective Cost
For UK tax-paying businesses, the Annual Investment Allowance (AIA) allows a 100% first-year deduction on qualifying plant and machinery — including solar panels — up to a limit of £1 million per year. This significantly reduces the effective after-tax cost of installation.
AIA Example: 300kW System
Installation cost: £220,000
AIA deduction (100% first year): £220,000 × 25% corporation tax = £55,000 tax saved
Effective after-tax cost: £165,000
This reduces the payback period by approximately 9–12 months compared to a simple pre-tax calculation.
The AIA is available to most businesses operating in the UK, including limited companies, partnerships and sole traders. The £1 million annual limit resets each tax year (April to April for most companies). Confirm eligibility and timing with your accountant, as the optimal tax year for the expenditure may affect the benefit available.
Real Quote Examples from UK Factories
The following anonymised examples illustrate real 2025–2026 installation quotes received by UK manufacturing businesses. These represent actual project costs, not estimates.
Plastics Manufacturer, West Midlands
Injection moulding facility, steel profiled roof, single-storey
System Size
85kW
Total Cost
£62,000
Cost per kWp
£730/kWp
Projected Payback
3.8 years
Notes: Straightforward flat roof installation. G99 application completed within 6 weeks with no network reinforcement required. Annual saving projected at £16,400 based on 30p/kWh blended rate.
Food Manufacturer, Yorkshire
Ready meals production, large flat roof, two buildings
System Size
320kW
Total Cost
£218,000
Cost per kWp
£681/kWp
Projected Payback
3.0 years
Notes: Two-building installation allowed cost efficiencies. DNO required a protection relay upgrade (£4,200) included in the above total. Annual saving projected at £72,000 with 62% daytime offset. IETF Phase 3 grant reduced net cost by £40,000.
Distribution Centre, East Midlands
Last-mile logistics hub, new-build facility with TPO flat roof
System Size
650kW
Total Cost
£430,000
Cost per kWp
£662/kWp
Projected Payback
3.5 years
Notes: Economies of scale clearly visible at this system size. New-build meant no roof repairs required. G99 took 14 weeks due to DNO queue in the region. Annual saving projected at £123,500. System satisfies major retail customer Scope 3 reporting requirement.