Solar panels for agriculture: turning big barn and grain-store roofs into farm income
Solar panels for agriculture make their clearest case on the arable and mixed farm, where the largest, simplest roofs in the country sit over grain stores, machinery sheds and covered yards, and where the pressure to control energy cost has rarely been sharper. Those roofs are usually south-facing or close to it, structurally clean, and free of the shading and listing constraints that complicate older buildings, so they are exactly the surfaces solar rewards. For an arable business squeezed between rising input costs and supermarket-led farm-gate prices, putting that roof area to work is one of the few cost levers genuinely within your control, and on many holdings it doubles as a diversification income through export or a land lease. This is whole-holding solar designed around how a working farm actually runs.
Why arable and mixed farms suit solar so well
Three things make a mixed arable holding a strong fit. First, the roofs: grain stores, grain dryers, machinery sheds and barns give you large clear spans of modern profiled steel that carry panels easily. Second, the economics of a controllable cost: energy is a significant cost on most UK farms, and unlike labour or feed you can cut a large share of it for two decades with a single capital decision. Third, the diversification angle: as the move from the Basic Payment Scheme towards the Sustainable Farming Incentive reshapes farm income, marginal land that crops poorly can earn a reliable rent, and exported generation becomes a second income stream rather than waste. There is a resilience dividend too. Rural grids fail more often than urban ones, and a well-designed array, especially paired with storage, keeps critical loads such as grain drying and ventilation running with less reliance on an exposed network.
How systems should be sized for a working farm
A good installer will not simply fill a roof to its edges. On an arable holding the defining feature is the grain dryer: a large but seasonal load that runs hard for a few autumn weeks and barely at all the rest of the year, so the array has to be matched to that pattern rather than to nameplate capacity. A typical arable rooftop system sits in the 30 to 500 kW band, roughly 55 to 920 plus panels across 200 to 3,000 plus square metres of roof, with ground-mount potential running to 5 MW and beyond where land and grid allow. A system of that size generates in the region of 24,000 to 500,000 kWh a year and saves between 3 and 65 tonnes of CO2e annually. There are two honest routes: size for the drying peak and lean on export income the rest of the year, or size smaller for daytime baseload and add a battery for the drying weeks. Ask the installer to pull your half-hourly meter data and crop calendar and model both, because the right answer differs from holding to holding.
Costs, payback and tax relief
An arable rooftop project typically runs £30,000 to £450,000 ex VAT with an indicative simple payback of roughly 6 to 13 years for a seasonal load that exports more, followed by well over a decade of effectively free generation. Where the case really turns, though, is on the tax side. Because solar PV counts as plant and machinery, the 100% Annual Investment Allowance allows most farm businesses to set the entire cost against first-year profit, which returns roughly a quarter of the project value in tax saved to a limited company and a similar amount under partnership or sole-trader structures. Most arable systems fall well within the £1m allowance cap and are relieved in full in year one under the AIA. Above the cap, companies can claim the 50% special-rate first-year allowance on the excess, with the balance going into the 6% special-rate pool. Either way, much of the relief is taken up front rather than spread across many years, which materially improves the early cash position. These figures are illustrative and move with tariff, roof orientation and whether you add storage; our cost guide sets out worked numbers, and the grants and funding page covers the tax and export side in full.
Funding routes for farm solar
The universal route is the 100% Annual Investment Allowance, which applies whether you trade as a company, a partnership or a sole trader. Beyond that, the Smart Export Guarantee pays for surplus units on eligible systems up to 5 MW (MCS certification is required up to 50 kW), with business rates in the region of 3 to 15p per kWh, and it matters more on an arable profile than in always-on sectors because the seasonal load means more is exported outside harvest. The Sustainable Farming Incentive does not pay for solar panels (it reopened as SFI26 in 2026, paying for land-management actions only), though land under a ground-mount array can sometimes sit alongside separate environmental actions, subject to scheme rules, so check with the RPA. No farm solar capital grant is open in England in 2026: Improving Farm Productivity round 2 closed at the end of July 2025 and FETF 2026 did not fund solar panels. Welsh and Scottish farms should check current devolved schemes, none of which pays for solar panels at the time of writing. Ask the installer to list any route you may qualify for in the proposal rather than leaving you to find them.
Compliance and sector considerations
Rooftop PV on agricultural buildings in England is generally permitted development under GPDO Part 14 Class J, with no capacity cap, though systems over 50 kW need prior approval from the local planning authority on design and glare, and listed buildings and scheduled monuments are excluded. Ground-mounted farm arrays should be treated as needing planning permission, and larger schemes may need EIA screening by the planning authority. A G99 grid application is required above 16 A per phase (about 11 kW three-phase), so almost every farm system needs one, and rural networks are frequently capacity-constrained, so connection studies come before final sizing. A common blocker is the roof itself: many pre-2000 farm buildings carry asbestos cement sheeting, which should not have panels fixed to it. Under the Control of Asbestos Regulations 2012 most asbestos-cement sheet removal is non-licensed work, but it must be done by trained, competent contractors following HSE guidance. The usual answer is a strip and reclad to profiled steel with PV on the new roof, and the solar business case often helps fund a re-roof that had been deferred for years. Where the land or buildings are tenanted, landlord consent is required for the structural alteration, and most institutional landlords operate standard tenant solar agreements. Check the installer's MCS certificate on the MCS register and ask which other accreditations, such as NICEIC or RECC, they hold.
What to expect from the installer
An arable project lives or dies on getting the seasonal sizing right, so a good installer starts with your half-hourly meter data and your crop calendar, modelling the grain-drying peak against the rest of the year before recommending rooftop, ground-mount, battery or a lease. Expect the installer to survey the buildings, check for asbestos and confirm the structure before issuing a written proposal, so the quoted figure holds with no surprises on the day. Because the grid connection is usually the slowest step, ask for the G99 application to go in early, alongside the survey, and where export capacity is tight ask whether a self-consumption-only design, a smaller no-export system, could shorten the connection timeline on a congested rural network. For tenanted land, involve the landlord early and ask whether the installer can supply a lease addendum. Check what insurance-backed workmanship warranty the installer offers, and agree a schedule around harvest and your busy seasons so the farm keeps running throughout.
An illustrative example
As an illustrative example, not a real farm or project: consider a large family arable farm with around 12 acres of marginal pasture unsuitable for cropping. Rather than own a system, it leases the land to a UK developer for a 1.8 MW ground-mount array of roughly 3,300 panels, generating about 1.7 million kWh a year. The lease runs 25 years at around 1,000 pounds per acre per year with a built-in ratchet, the land continues to graze sheep, and separate environmental actions may sit alongside the lease, subject to scheme rules. The figures here are illustrative and depend entirely on your farm, roof, load and tariff, or on your land, grid position and the developer terms available in your region; ask the installer or developer to model your own numbers from your meter data before anything is committed, and treat no worked example as a guaranteed outcome for a different holding.
If your holding mixes cropping with livestock, our pages on solar for arable farms and livestock units go into the detail for each enterprise. To weigh ownership against leasing, read the cost guide and the grants and funding page, then request a free quote from your meter data, or read the agricultural solar FAQs first.
