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 (8–15p/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
- Project value
- £45,000–£450,000
- Typical simple payback
- 6.5 years
- Annual generation
- 46,000–460,000 kWh
- Annual CO2 avoided
- 11–106 tonnes
Cost and economics
Grain store install economics in 2026: £45,000–£450,000 typical project value, 6.5-year simple payback, 46,000–460,000 kWh annual generation. Battery storage adds £55,000–£175,000 to capex but typically improves overall returns through demand-charge savings and time-shift of summer generation. For a 400 kW grain store install with 220 kWh battery serving a 14-day October drying season, the battery shaves around £4,000–£9,000 per year of grid demand charges plus captures around 2,800 kWh of time-shifted summer 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. We provide full DCF financial models with PVSyst yield modelling and 25-year IRR projections in every fixed-price proposal.
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; we coordinate 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
Grain store install timeline: weeks 1–3, survey including HH meter review and grain-drying season load profiling; weeks 3–5, design and fixed-price proposal covering PV-only and PV-plus-battery scenarios; weeks 5–7, contract and DNO G99 application (ground-mount projects may need separate planning consultation); weeks 7–14, procurement and access; weeks 14–18, install — typically 2–4 weeks for a 300–500 kW grain store install scheduled outside the May–September preparation and August–November drying season; week 18, commissioning. We avoid harvest and drying-season install windows whenever possible — sharing access roads and yards with harvest traffic creates risk and delay for both us and the farm.
A representative recent grain stores & arable barns install
A typical Lincolnshire arable install: 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. We delivered 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. First-year generation 612,000 kWh; annual savings £94,000 across cost avoidance and SEG export. Simple payback 6.4 years. SFI biodiversity bundle stacks under the ground-mount, generating an additional £8,500/year. The Tesco supplier audit team referenced the install in renewed 2025 contract terms.
See more examples in our case studies library — we publish full project narratives across every sub-vertical we work in.
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
Get a fixed-price proposal for your grain stores & arable barns install
Every quote starts with a free desk-based feasibility study from your half-hourly meter data and building dimensions. We share an indicative system size, generation forecast, self-consumption ratio, and 25-year financial model within 7 working days. If the numbers work, our engineers visit for a one-day structural and electrical survey, after which we deliver a fixed-price proposal with full PVSyst yield modelling and DCF financial model. Most grain stores & arable barns installs commission in 4–7 months from contract; combined re-roof + PV programmes add 2–3 months. Send your meter data via our quote form or contact us directly to get started.
Common questions
How much do solar panels for farm buildings cost in the UK?
For a typical UK farm-building PV install in 2026, cost per kW is roughly £900–£1,100 for systems under 50 kW (small barn, dairy parlour, equestrian arena), £800–£950 per kW for 50–250 kW systems (typical livestock shed, mid-size grain store, poultry shed), and £700–£850 per kW for systems above 250 kW (large multi-bay barns, intensive poultry or pig units, big grain stores). Combined re-roof and PV (asbestos replacement) adds £25–£45/sqm to capex but is often the only viable path on pre-2000 buildings. We provide a fixed-price proposal within 7 working days of receiving meter data and roof dimensions.
Can we put solar panels on asbestos cement barn roofs?
No — asbestos cement roofs must be replaced before any rooftop PV install. The Control of Asbestos Regulations 2012 prohibits drilling, fixing, or load-imposing on asbestos cement sheeting. The standard approach is a combined re-roof + PV project: a licensed asbestos contractor removes the cement sheets, the structure is upgraded if needed, profiled steel or membrane is installed, then PV mounts to the new roof. The PV business case routinely pays for 60–100% of the re-roof cost over the 25-year system life.
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?
Headline schemes: 100% Annual Investment Allowance (universal — up to 25% effective tax saving year one), Sustainable Farming Incentive (SFI 2025 actions for biodiversity and agrivoltaic pairings), Farming Investment Fund (capital grants on solar-paired investments like robotic milking or grain dryers), Smart Export Guarantee (8–15p/kWh on surplus export). Welsh and Scottish farms have additional devolved schemes (Rural Investment Schemes) often with higher intervention rates than English equivalents.
Do we need planning permission for solar on agricultural buildings?
Most rooftop installs on agricultural buildings fall under Class A Part 14 GPDO 2015 Permitted Development — no planning permission needed. The exceptions are: listed agricultural buildings (Listed Building Consent required), National Parks and AONBs (sometimes Article 4 directions in force), Conservation Areas, and ground-mount above 9m × 9m × 4m height. We handle planning consultation as part of every project — typically a 4–8 week timeline if planning is required.