Why grain stores & arable barns are an excellent fit for commercial rooftop PV
Modern UK grain stores represent the largest single-building roof areas in rural infrastructure. Cereal and oilseed crop storage buildings on commercial arable farms typically deliver clear-span roof areas of 1,500 to 3,500 square metres per building — often the equivalent of three rugby pitches in contiguous south- or east-west-facing PV-suitable cladding. The structural pattern (steel-portal frame, profiled metal cladding designed for snow and wind loadings well in excess of PV racking dead load) makes retrofit straightforward. The complication for grain-store PV is the load profile: heavy electrical demand sits in a 3–5 week harvest drying season, with low demand the rest of the year. Sizing and battery decisions are critical to optimise the economics.
System sizing for grain stores & arable barns
Grain store PV sizing depends on three factors: roof area available, on-farm load profile through the year, and DNO export capacity. The simplest case is a modern 2,500 sqm clear-span grain store with no significant year-round baseload — here, size for total roof potential (400–500 kW), lean on Smart Export Guarantee through the year, accept 6–7 year payback. The more sophisticated case adds battery storage (typically 150–250 kWh) to time-shift summer generation into the autumn drying-season peak, shaving peak grid demand and capturing the price differential between grid retail (24–28p/kWh) and SEG export (4–12p/kWh). For multi-building arable farms with workshops, machinery sheds and grain stores combined, the optimal configuration is often PV on every suitable building under a single G99 application with one central battery.
Typical grain stores & arable barns install at a glance
- System size range
- 50–500 kW
- Panel count
- 92–920
- Roof area needed
- 300–3,000 sqm
- Annual generation
- 46,000–460,000 kWh
- Annual CO2 avoided
- 11–106 tonnes
Cost and economics
Grain store install economics in 2026: 50–500 kW typical systems, 46,000–460,000 kWh annual generation. Combined re-roof + PV is uncommon on grain stores (most are post-2000 builds with modern cladding) but does apply to older multi-purpose Dutch barns and historic stone-clad farm buildings being repurposed for grain storage.
Compare these numbers against the wider cost of farm-building solar in 2026 and the grants and finance routes available. Ask each installer to show its yield and financial assumptions in writing, and compare them with the farm solar payback calculator.
A seasonal drying load changes what an array earns; model your own spend in the farm solar payback calculator to estimate the payback for this roof.
Compliance and regulation
Grain dust is a known explosion hazard — areas around grain handling are commonly designated ATEX Zone 22 (dust ignition risk). Cable penetrations, electrical equipment and PV string-isolator placement must respect zone classification. Grain elevator motors, drying-fan motors and conveyor drives are typically 415V three-phase and pair well with PV inverter integration; your installer coordinates with the grain-drying equipment OEM (Tornum, Riela, Master Farm Services, Allmet) to ensure no electrical interference. NABIM (National Association of British and Irish Millers) supplier requirements are unaffected. AIC (Agricultural Industries Confederation) members benefit from documented sustainability metrics — a PV install is auditable evidence at every AIC quality review.
Install programme and timeline
What an install involves: a structural and electrical survey, a design and written proposal, the DNO G99 application, procurement, installation and commissioning. Ask each installer for its programme in writing; the grid connection is usually the longest step, so apply early. See the planning guide for the Class J limits.
A modelled grain stores & arable barns scenario
A typical Lincolnshire arable scenario: 2,200-acre family farm with three grain stores totalling 4,500 sqm of clear-span roof, heavy autumn drying load, and 14 acres of marginal pasture unsuitable for cropping. The modelled scope is a hybrid system: 380 kW rooftop PV across two of the three grain stores, 260 kW ground-mount on the marginal pasture with sheep grazing under raised panels, and a 220 kWh battery system supporting peak-shaving during October–November grain drying. Modelled year-one generation: 612,000 kWh; modelled annual savings: £94,000 across cost avoidance and SEG export. Simple payback 6.4 years. An SFI biodiversity bundle can stack under the ground-mount, worth roughly £8,500/year. For a major-retailer supplier, this is exactly the Scope 2 evidence audit teams look for at contract renewal.
More modelled worked examples are in the case studies library; each is labelled as modelled, not a named client project.
Key features and capabilities for grain stores & arable barns
- Modern grain stores often 1,000–3,000 sqm clear-span — among the largest commercial roofs in rural UK
- Grain drying is a major seasonal load — PV typically pairs with battery for peak-period drying support
- Strong fit with ground-mount addition on adjacent farmyard hardstanding
Send your grain stores & arable barns roof details
Tell us the building, the roof sheeting and what you want to know. Send your details through the quote form and we reply by email. Before you sign with any installer, check their MCS certificate on the MCS register and ask for the structural, roof-condition and grid assumptions in writing.
Common questions
How much do solar panels for farm buildings cost in the UK?
DESNZ's solar PV cost data for 2025/26 puts the mean installed cost of 10-50 kW projects at about £1,267 per kW (median about £1,204 per kW), and non-domestic 10-50 kW installations at about £1,167 per kW. The series covers all building types, not farm buildings alone, and stops at 50 kW. Your price depends on roof access, any re-roofing, cabling distance to the intake and the grid connection. The cost page on this site sets out the regional figures and the method; treat them as a benchmark and compare written quotes against them.
Can we put solar panels on asbestos cement barn roofs?
Not directly: installers will not normally fix through asbestos cement sheets, so the roof is overclad or replaced before the panels go on. HSE says most work on asbestos cement is non-licensed provided the people doing it are informed, instructed and trained, and its task sheet A14 asks whether the sheets can be overlaid with non-asbestos material instead of removed. Price the roof work and the PV separately: the roof is building fabric, the PV is plant, and the two are treated differently for tax.
Which farm building should we install solar on first?
Prioritise by three criteria: (1) roof area and orientation — the biggest south-facing clear-span roof in sound structural condition wins; (2) on-site daytime load — dairy parlours, grain stores during harvest, intensive livestock houses, and farm workshops all have year-round or seasonal daytime baseload; (3) install access and biosecurity complexity — workshops and grain stores typically have lower biosecurity friction than poultry or pig units, but the latter often have much larger roofs. We rank each building during feasibility on payback, self-consumption, and complexity.
Will solar panels work on a curved or arched barn roof?
Generally no — modern PV requires a structural surface with adequate purlin spacing and slope (typically 5° to 35°). Curved Dutch-barn or hooped sheds need either a separate flat or pitched roof to be installed (rare), a ground-mount alternative, or — most commonly — a different building on the farm chosen as the PV host. We assess every farm holistically rather than fixating on a single building.
What grants are available for farm-building solar in 2026?
No capital grant for rooftop solar on farm buildings was open in England, Wales, Scotland or Northern Ireland when checked on 3 November 2026. What does apply: the 100% Annual Investment Allowance on the PV plant (UK-wide; solar is special-rate plant), Smart Export Guarantee income in Great Britain (Northern Ireland has no SEG; suppliers there set their own export rates), and the Workplace Charging Scheme if EV chargers are part of the project. The Sustainable Farming Incentive pays for land-management actions, not solar. The grants and funding guide sets out each nation and the alternatives when no grant fits.
Do we need planning permission for solar on agricultural buildings?
Rooftop solar on a non-domestic building such as a farm shed is usually permitted development under Class J of Part 14 of Schedule 2 to the GPDO 2015, inside its physical limits. Above 50 kW you must apply for prior approval on design, appearance and glare. Listed buildings and some designated land are treated differently, and ground-mounted arrays follow other rules. The planning guide on this site sets out the current rules; confirm with your local planning authority before you commit.