Solar Panels for Farm Buildings Cost — UK Price Guide 2025

The cost of solar panels for farm buildings in the UK typically ranges from £15,000 for a small 10 kW system on a machinery shed to over £200,000 for a large 150+ kW commercial installation across multiple buildings. The most common farm building installations fall in the 30-100 kW range, costing £30,000-£100,000 before grants and tax relief. After a 25% Farming Investment Fund grant and Annual Investment Allowance tax relief, the net cost is typically 30-45% lower than the gross price.

In 2025, agricultural solar installations cost between £800 and £1,200 per kWp (kilowatt-peak) depending on system size, roof type, and any additional works required. Larger systems benefit from economies of scale: a 20 kW system might cost £1,100/kWp, while a 100 kW system can come in at £850-£950/kWp. These figures include panels, inverters, mounting hardware, electrical installation, scaffolding, and DNO application. They exclude battery storage, which adds £500-£800 per kWh of storage capacity.

The payback period for solar panels on UK farm buildings is typically 5-8 years when you account for energy savings, Smart Export Guarantee income, and any grants received. After payback, you enjoy free electricity for the remaining 17-20+ years of the system life. Dairy farms with high continuous energy loads often see payback in 4-6 years. The payback period is shortened significantly by rising electricity prices — farms locked into contracts above 25p/kWh are seeing payback in as little as 3-4 years on well-designed systems.

Ground-mounted solar arrays on farmland are typically 10-20% more expensive per kWp than equivalent roof-mounted systems due to the additional costs of groundworks, fencing, cable trenching, and mounting structures. However, ground mounts offer greater design flexibility, can achieve optimal panel orientation and tilt angles, and are easier to maintain. For farms with unsuitable roofing but available land, ground-mount costs of £900-£1,300/kWp are common for agricultural scale installations.

Battery storage typically adds £8,000-£40,000 to a farm solar installation depending on capacity. For a farm needing 20 kWh of usable storage, expect to add around £12,000-£18,000 to the system cost. The financial case for battery storage is strongest on farms with significant early morning and late evening energy loads (dairy, poultry, pig) where solar generation does not align with peak consumption. Many farms achieve 70-80% self-sufficiency with solar alone; battery storage can push this to 85-95%.

Yes, roof structure significantly affects installation cost. Fibre cement or steel profile roofs on modern agricultural buildings are the simplest to install on and attract the lowest labour premiums. Older asbestos cement roofs may require encapsulation or replacement before solar can be installed — this adds £15-£40 per square metre. Timber-framed buildings require structural assessment and potentially reinforcement. We provide a free structural assessment as part of every site survey, so you know the full cost before committing.