Solar Panels for Barns and Agricultural Buildings

Generate free electricity from your barn roof, reduce farm energy bills and future-proof your operation for electric farm machinery — with no planning permission needed on most 5ha+ holdings.

Why Barns Are Perfect for Solar Panels

Agricultural barns are among the most solar-ideal structures in the UK. Portal frame and monopitch steel buildings are structurally robust, typically south or south-east facing, free from planning constraints that affect urban buildings, and located in the open countryside away from shading. The combination of strong roof structure, optimal orientation and Class R permitted development rights makes barn solar one of the most straightforward commercial solar projects to approve, install and generate strong returns from.

Farm energy costs have risen dramatically since 2021. Grain drying, ventilation, refrigeration, irrigation pumps, milking equipment and general farm operations are all energy-intensive. A 200kW barn solar system generating 190,000 kWh/year can offset the entire electricity bill for a medium-sized arable or mixed farm — often with surplus for export income under the Smart Export Guarantee.

The agriculture sector is also under pressure from Net Zero commitments. Farm businesses participating in the Sustainable Farming Incentive (SFI) and Countryside Stewardship schemes are expected to demonstrate environmental performance. Solar installation on farm buildings reduces Scope 2 emissions and demonstrates sustainability credentials to processors, retailers and supply chain partners.

Asbestos Cement Barn Roofs: What You Need to Know

Millions of square metres of agricultural barn roofing in the UK consists of asbestos cement corrugated sheet — a legacy material widely used from the 1950s to the 1980s. Asbestos cement (AC) contains 10–15% chrysotile (white asbestos) bonded into the cement matrix. The fibres are not released under normal conditions but can become airborne if the sheets are disturbed, cut or drilled.

Installing solar on an AC barn roof requires specialist knowledge and equipment. All installers working on AC roofs must hold RICS-accredited asbestos training and use non-penetration mounting systems that avoid drilling through asbestos sheets. The most common approach is a roof clamp or purlin-clamp system that fixes to the steel purlin below the AC sheet without touching the sheet itself.

• Pre-installation: asbestos survey by a licensed asbestos surveyor (Type 2 survey minimum)
• Confirm sheet condition — friable, cracked or delaminating AC may need specialist treatment before installation
• Non-penetration mounting: Clenergy No-Drill, SunRoof, or equivalent purlin-clamp systems
• No cutting, drilling or grinding of AC sheets during installation
• Disposal: any AC waste must be handled by licensed contractors and disposed at licensed sites
• Documentation: Health & Safety file updated with asbestos location plan post-installation

Permitted Development for Barn Solar

Class A permitted development rights in England allow solar panels to be installed on agricultural buildings on holdings of 5 hectares or more, without needing full planning permission, subject to prior approval. The key criteria are:

On holdings under 5ha, or in National Parks, AONBs or World Heritage Sites, full planning permission is required. Welsh, Scottish and Northern Irish planning systems have equivalent but separately-legislated permitted development rights — we guide clients through the correct process for their location.

Barn Roof Types and System Design

Profiled Steel Sheet (Plastisol/Polyester Coated)

Modern steel agricultural buildings typically use 32/1000 or 34/1000 profiled steel sheet, which is ideal for standard in-roof or on-roof solar mounting. Aluminium roof hooks or standing-seam clips fix directly to the profile without roof penetration, providing a secure anchor point for racking rails and panels.

Fibre Cement Sheet (Post-Asbestos Era)

Buildings constructed from the 1990s onwards commonly use fibre cement sheet (FC) — a synthetic alternative to AC with no asbestos content. FC roofs are suitable for standard hook-mounted solar arrays. However, FC is more brittle than AC; specialist walking boards and low-load installation techniques are still recommended.

Traditional Clay Tile and Slate Barn Roofs

Older stone barns converted from traditional agricultural use often have clay tile or natural slate roofs. These are suitable for in-roof and on-roof solar but require survey to assess structural adequacy — the additional loading of a solar array may require timber rafter reinforcement in older structures. Listed barn constraints apply in conservation areas.

Rural Grid Connections for Barn Solar

Rural farms often connect to lower-voltage distribution networks that lack the capacity for large solar exports. DNO connection costs are the most variable element of a barn solar project and must be assessed early in the process.

For systems under 3.68kW (single-phase residential), connection is straightforward. For agricultural systems of 50kW+, G99 applications to the relevant DNO are required. Rural single-phase supplies may need three-phase upgrading to carry solar export, adding £5,000–£15,000 to DNO costs.

A useful strategy to reduce DNO export costs is to size the system primarily for self-consumption rather than export. A 150kW barn system that uses 90% of its generation in grain drying, ventilation and farm operations needs a much smaller export connection than a 150kW system in export-led operation. We model self-consumption vs export economics for every barn project.

Farm EV Charging Integration

Electric farm vehicles are arriving faster than many farmers expected. John Deere's electric utility vehicles, New Holland's electric tractor prototype and Fendt's e100 Vario have all been commercially demonstrated. The UK government's Future Farms programme includes provisions for zero-emission agricultural machinery grants.

Barn solar generates exactly when farm vehicles are most active — daytime operations. A 200kW barn system can supply sufficient energy to charge 4–6 electric vehicles simultaneously at 22kW AC, or 2–3 faster DC-capable machines, without drawing from the grid. Adding a 100kWh LFP battery allows overnight charging from stored solar.

The OZEV Workplace Charging Scheme provides grants of 75% (up to £350/socket) for up to 40 charge point sockets. Farm businesses qualify for this grant for farm vehicle charging points, providing an additional funding stream on top of the barn solar installation.

Case Studies

Frequently Asked Questions

Barn Solar Panel System Sizing: From 30kWp to 500kWp

The right solar system size for a barn or agricultural building depends on the roof area, roof condition, electricity consumption, and whether you are targeting self-consumption or maximising generation with grid export. Here is a practical guide to barn solar sizing:

Asbestos Cement Roof Barns: What You Need to Know

A significant proportion of UK agricultural buildings built between 1950 and 1990 have asbestos cement (AC) roofing — typically corrugated fibre cement sheets containing chrysotile (white asbestos). Solar panels can be installed on intact asbestos cement roofs providing specific precautions are followed. The key requirement is that the AC sheets must be non-fragile tested and must not be disturbed during installation. Our team uses non-penetrating clamp and rail systems that attach to the AC sheet's corrugations without drilling or cutting. A condition survey is carried out before any work.

Class R Permitted Development for Barn Solar

Most barn solar installations in England qualify as Permitted Development under Class R of the Town and Country Planning (General Permitted Development) (England) Order 2015 as amended. Class R allows ground-mounted solar on agricultural land over 5 hectares for a farm's own energy use. For barn roof-mounted solar, Class A covers up to 1MW on commercial buildings. Scotland (Class 67), Wales and Northern Ireland have separate PD rights with slightly different thresholds. Our planning team confirms your PD status at every site survey.