Agricultural solar is not domestic solar scaled up. Farm roofs range from fibre-cement barns to steel portal-frame sheds and listed stone ranges; supplies may be single-phase at the end of a rural line; and the work has to fit around milking, harvest and lambing. This page sets out what a sound installation process looks like, so you can judge the quotes you receive. SolarPanelsForFarms.uk is an independent guide, not an installer.
1. Meter data and desk feasibility
A good proposal starts from twelve months of half-hourly meter data, not a rule of thumb. It shows when the farm uses power, so the array can be sized to daytime demand — electricity used on site is worth several times what an export earns. A desk study then models generation from the roof's orientation and pitch (PVGIS is the standard free model) and gives an indicative size and cost. As a reference point, DESNZ's 2025/26 data put the median installed price of 10–50 kW systems at £1,262 per kW; our farm solar cost guide has the detail.
2. Site survey
The survey decides whether the roof can take the system and how it will be fixed:
- Structure. MCS's installation standard requires the roof structure to be checked by a suitably competent person, and by a structural engineer for unusual roofs — signs of distress, later alterations, a pitch under 30° or features that trap snow.
- Roof covering. Steel sheet needs the right kit for its profile and enough thickness for the fixings — see solar panels on metal roofs. Asbestos cement is fragile and needs its own method — see solar panels on asbestos roofs.
- Rooflights and access. In agriculture, roughly half the deaths and serious injuries from falls involve fragile roofs, HSE says; the survey should plan safe access and rooflight protection.
- The electrical supply. Single- or three-phase, its capacity and where the inverters and cabling will go.
3. Design and quotation
The quotation should itemise the panels, inverters, mounting kit, scaffolding or access, electrical work, monitoring, the grid application and commissioning — and state the expected generation and the assumptions behind it. Compare quotes on price per kW and on what is included, not just the total. If you are weighing a battery, ask for the case with and without it, from the same meter data.
4. Grid approval and planning
Above 16 A per phase — 3.68 kW on a single-phase supply — the network operator must approve the system under G99 before it is connected, and its offer may bring costs or an export limit (farm solar grid connection explains the process). In England, panels on a farm building's roof are normally permitted development under Class J, with prior approval on design and glare above 50 kW; Scotland, Wales and Northern Ireland have their own rules (planning permission for farm solar). Order nothing until both are clear.
5. Installation
For MCS installations on pitched roofs the mounting kit must be certified to MCS 012, which tests kits for wind uplift, fire and weathertightness. The work is done at height on roofs that may be fragile, so ask how edge protection and rooflight protection will be handled, and agree the programme around the farm calendar — milking times, harvest, housing and lambing.
6. Commissioning and handover
Commissioning tests to IEC 62446-1 — string voltages and currents, insulation resistance, inverter settings — become the baseline for every future inspection, so make sure you receive the results. Handover should also include the MCS certificate (for systems up to 50 kW), the network operator's paperwork, the monitoring login and warranty documents. Registering for the Smart Export Guarantee in Great Britain needs MCS or an equivalent certification up to 50 kW, or an installation certified to the supplier's satisfaction above that. After handover, see what to monitor and the farm solar maintenance guide.
What to ask an installer
- Is the company MCS-certified for solar PV, and will the system be MCS-registered if it is 50 kW or under?
- Is the mounting kit certified to MCS 012 for this roof type?
- Who checks the roof structure, and is a structural engineer involved?
- Who makes the G99 application, and what happens if the offer includes an export limit?
- What generation do you expect, from which model, and what share will the farm use?
- How is the workmanship warranty protected if your company stops trading?
- How will rooflights and roof edges be protected during the work?
On funding: no farm scheme in any UK nation funds solar panels as of 3 November 2026, and Northern Ireland's 20% NISEP grant for business solar has closed for its 2026/27 round — see solar grants for farmers — but capital allowances on solar panels usually let the whole cost come off taxable profits in the year of purchase.
Frequently asked questions
How long does a farm solar installation take?
The work on the roof is usually the short part. The longer steps come first: the roof and structure checks, the network operator's G99 approval for anything above 16 A per phase, and any planning prior approval for systems above 50 kW in England. Ask the installer for a programme that shows those steps, not just the installation dates.
Do I need planning permission to install solar on my farm?
Usually not for panels on the roof of a farm building. In England they are normally permitted development under Class J — no more than 0.2 m proud of a pitched roof and at least 1 m from the edge — with prior approval on design and glare above 50 kW. Listed buildings are excluded, and Scotland, Wales and Northern Ireland have their own rules; Northern Ireland limits permitted development to 50 kW.
What size of system does my farm need?
Size it from twelve months of half-hourly meter data, so the array matches the farm's daytime demand. Electricity used on site is worth several times what an export pays, so an array much bigger than the farm can use rarely pays back as well as a right-sized one.
Can solar go on an asbestos-cement barn roof?
Often, but it needs care. HSE treats asbestos-cement roofs as fragile, and its guidance favours fixing over the existing sheets without disturbing them where the roof is sound; intact sheets removed in small-scale work are not licensed work, but damaged material changes that. A survey decides which route is safe.
What certification should a farm solar installer have?
For systems up to 50 kW, MCS certification — Smart Export Guarantee suppliers ask for MCS or an equivalent. For larger systems, ask for evidence of the same standards anyway, and check the installer's insurance and how its workmanship warranty is protected if it stops trading.