Solar Panels for Factories & Manufacturing Plants

Why UK Factories Are Switching to Solar in 2026

Manufacturing is the UK's most energy-intensive sector, with factories spending an average of £180,000–£2.4 million per year on electricity depending on size and process type. Industrial electricity tariffs have remained elevated since 2022, averaging 27–35p/kWh for UK manufacturers in 2026. Solar panels directly offset grid consumption during production hours, delivering immediate and measurable cost savings.

Beyond cost reduction, solar enables UK manufacturers to address three pressing business pressures simultaneously: Supply chain sustainability requirements from customers (particularly automotive OEMs and major retailers requiring Scope 2 emissions reporting), ESOS compliance obligations, and competitive pressure from EU-based competitors who benefit from lower industrial electricity prices. A 200kWp factory solar installation reduces Scope 2 emissions by approximately 47 tonnes CO2e per year — equivalent to removing 20 cars from the road.

Factory Solar System Sizing by Industry

The right system size depends on your factory's annual electricity consumption, available roof area, and daytime operational profile. Factories with heavy daytime electricity use (production runs, HVAC, compressors) benefit most from solar, as generation aligns with consumption during working hours.

Industry Type	Typical Annual Usage	Recommended System	Annual Saving	Payback
Food & Beverage Production	800,000–3,000,000 kWh	200–500kWp	£54k–£160k	3–5yr
Automotive Component	500,000–2,500,000 kWh	150–400kWp	£40k–£130k	3–5yr
Plastics & Packaging	400,000–1,500,000 kWh	100–300kWp	£27k–£80k	4–5yr
Metal Fabrication & Machining	300,000–1,200,000 kWh	100–250kWp	£27k–£65k	4–6yr
Pharmaceuticals & Chemicals	600,000–4,000,000 kWh	200–500kWp	£54k–£160k	3–5yr
Electronics & Assembly	200,000–800,000 kWh	75–200kWp	£20k–£54k	4–6yr
Printing & Publishing	300,000–1,000,000 kWh	100–200kWp	£27k–£54k	4–5yr
Textiles & Apparel	250,000–900,000 kWh	75–200kWp	£20k–£54k	4–6yr

Industrial Energy Transformation Fund (IETF): closed

Older guides describe the IETF as the most generous capital grant for factory solar. It closed in July 2025 with no successor fund — after the Spending Review the government decided there would be no further extension, and the planned second Phase 3 window was cancelled, so the spring 2024 window (29 January to 19 April 2024) was the last. Even while it ran, solar was typically fundable only as part of a wider process-decarbonisation project, not on its own.

What reduces the cost of factory solar now is the Annual Investment Allowance, the 50% special-rate first-year allowance above the AIA cap, Freeport enhanced capital allowances inside a tax site, and a Power Purchase Agreement where zero capital is the requirement. See what the IETF closure means for factory solar.

Technical Considerations for Factory Installations

Three-Phase Power and Solar Integration

Virtually all UK factories operate on a three-phase 400V power supply, sometimes with high-voltage (HV) connections for very large sites. Factory solar installations use three-phase string or central inverters to match your grid connection. For sites with HV connections (above 1MW demand), installers design solar systems using HV inverters that integrate directly with your LV/HV transformer arrangement — avoiding the need for expensive additional grid infrastructure.

G99 Grid Connection for Factory Solar

Factory solar systems over 50kWp require a G99 grid connection application to your Distribution Network Operator (DNO). The G99 process involves technical specification submission, a feasibility study, and formal approval — typically taking 16–20 weeks from application to connection. Key issues for factory solar include: export limitation (many DNOs restrict factory solar to zero-export initially), protection relay coordination, and metering arrangements under half-hourly settlement. The installer manages the complete G99 process, including pre-application discussions with the DNO to identify potential constraints early.

Factory Roof Suitability

Most UK factory buildings have large, flat or low-pitched roofs that are excellent candidates for solar. Common factory roof types and their considerations:

• Profiled metal (box profile or standing seam): The preferred roof type for factory solar. Clamp-mounted systems require no roof penetrations and can be installed without affecting the roof warranty. Most cost-effective installation.
• Built-up felt (BUR) or single-ply membrane: Ballasted systems are typically used, requiring structural assessment to confirm the roof can carry the additional load (typically 15–25 kg/m²). Penetration systems are available where ballasted is not possible.
• Asbestos cement (AC) sheets: Common on older factory buildings. AC sheets must be tested and may require overcladding before solar installation. Installers can manage the full overcladding and solar process together.
• Concrete or SARNAFIL membrane: Suitable for ballasted systems. Structural confirmation required. Often found on modern logistics/factory units.

Daytime Load Matching for Manufacturing

The key to maximising factory solar ROI is matching generation profile to consumption profile. UK solar generation peaks between 9am–4pm in summer and 10am–2pm in winter — aligning well with standard factory shift patterns. A single-shift 7am–6pm operation will typically self-consume 65–80% of all solar generation. Double-shift or 24/7 factories may only self-consume 50–60%, making battery storage an important complement.

The installer should assess your factory's half-hourly meter data (available from your energy supplier or broker) to model self-consumption before quoting. This ensures you receive an accurate financial projection, not optimistic assumptions. For factories with significant off-peak consumption, installers also model solar-plus-battery scenarios that can extend effective self-consumption to 80–90%.

ESOS Compliance and Scope 2 Reporting

The Energy Savings Opportunity Scheme (ESOS) requires UK businesses with 250+ employees or £50M+ turnover to conduct energy audits every four years. Solar panels directly address the grid electricity component of your ESOS energy profile, providing measurable evidence of energy reduction investment. For manufacturers supplying major retailers or automotive OEMs, Scope 2 emissions reporting (electricity) is increasingly a supply chain requirement — installing solar is the most direct way to reduce Scope 2 emissions at your site.

Annual Investment Allowance for Factory Solar

Factory solar installations qualify for the Annual Investment Allowance (AIA) in full in the first year of installation — up to £1M per business. At the 25% corporation tax rate, a £200,000 solar installation generates £50,000 in tax savings in Year 1, effectively reducing net cost to £150,000. For a company paying 19–25% corporation tax, that relief alone brings the effective project cost down by 19–25%.

Manufacturing sectors and their solar considerations

Each manufacturing sector has specific considerations — from ATEX hazardous zone requirements in chemical processing to clean room air handling loads in pharmaceutical manufacturing. Check that the installer you appoint has worked in yours.

• Automotive & Aerospace: Large facilities with heavy compressor and tooling loads, typically ESOS-obligated
• Food & Beverage Production: High refrigeration and process heating loads, BRC accreditation requirements, daytime production shift alignment
• Plastics & Injection Moulding: Heavy compressor loads, excellent daytime alignment, strong economics with 3–4yr payback typical
• Metal Fabrication & Welding: Three-phase heavy draw equipment, solar reduces peak demand charges significantly
• Electronics Assembly: Clean room HVAC loads, ESD-safe installation required, typically smaller systems on precision engineering buildings
• Pharmaceutical & Chemical: ATEX zone considerations, stringent roof penetration controls, G99 complexity from HV connections
• Logistics & Distribution: Large flat roofs ideal for solar, overnight charging (EV fleet) increasingly combined with battery storage

Worked example (modelled): 210kWp Automotive Component Manufacturer

Illustrative, modelled scenario — not a real project. This site is an independent publisher and holds no project data.

A West Midlands automotive component supplier installs a 210kWp system across a 4,800m² factory roof. Annual electricity consumption is 680,000 kWh at an average 31p/kWh (£210,800/year). The array generates about 187,000 kWh/year, 75% self-consumed during production, saving roughly £43,600 per year. On a £188,000 project cost, the Annual Investment Allowance at 25% corporation tax returns £47,000 in year one, leaving a net £141,000 and a payback of about 3.2 years (4.3 years before tax relief).

UK-Wide Factory Solar Coverage

Factory solar is installed across all major UK manufacturing regions: West Midlands (Coventry, Birmingham, Wolverhampton, Walsall), East Midlands (Nottingham, Derby, Leicester, Loughborough), North West (Manchester, Liverpool, Bolton, Warrington), Yorkshire (Sheffield, Leeds, Bradford, Doncaster), South East (Reading, Swindon, Crawley), South West (Bristol, Exeter, Plymouth), and Scotland (Glasgow, Edinburgh, Aberdeen).