How much do solar panels for farm buildings cost?

Farm solar cost per kW: what the official data covers

There is no single price list for farm-building solar. The only official cost series is the DESNZ release set out below, and it is the baseline to start from. The cost pages by system size apply that baseline to an array of each size: 50 kW, 100 kW, 250 kW and 500 kW.

What the official installation data says (DESNZ, May 2026)

The Department for Energy Security and Net Zero publishes the installed cost of every solar system registered on the MCS installation database. The release of 28 May 2026, covering the 2025/26 financial year on a total-installed-capacity basis, is the only official cost series for UK solar and the right starting point for a farm-building quote. Its limits matter as much as its figures: MCS covers installations up to 50 kW, so a 100 kW grain-store roof is outside the series, and the averages are for all building types, not farm buildings alone.

The same release gives regional means for the 10–50 kW band: £1,162 per kW in the North East, £1,233 in the West Midlands, £1,237 in Yorkshire and the Humber, £1,241 in the East of England, £1,248 in the North West, £1,253 in the East Midlands, £1,257 in Wales, £1,289 in the South West, £1,321 in Scotland and £1,330 in the South East. Multiply by the array size for the official baseline, then expect a farm quote to move for the reasons on this page: roof condition and access, the three-phase connection and any G99 works, cable runs between buildings, and the inverter and module specification. The two component decisions are set out on solar panel comparison for farm roofs and solar inverters for farm buildings. Source: DESNZ, Solar photovoltaic (PV) cost data, summary and regional tables (TIC), published 28 May 2026.

What changes the price by building type

Buildings with continuous daytime load (dairy, poultry, pigs, cold stores) support larger arrays and use more of the output on site; stores and workshops with seasonal or spiky load usually size to the load rather than the roof. None of that sets the installed price by itself: roof condition and access, the structure, the connection and the equipment do. The rules for each building are on solar panels for agricultural buildings.

The single biggest cost variable is an asbestos cement roof. Installers will not normally fix through asbestos cement sheets, so the roof is overclad or replaced first. HSE says most work on asbestos cement is non-licensed provided the people doing it are informed, instructed and trained. The options and what a quote should list are in overclad or strip an asbestos cement farm roof, and the legal position is on solar panels on asbestos cement farm roofs. The cost depends on sheet area, access, roof lights, disposal and whether the building stays in use; this page prints no figure for it because none of the guidance publishes one.

Financing routes for farm clients

Three financing routes are available to UK farm clients in 2026:

Capital purchase with 100% Annual Investment Allowance. The simplest route for farms with capital available. Full system capex paid upfront. The PV system qualifies as plant and machinery — fully expensable against trading profit in year one under the £1m AIA cap (which comfortably covers almost every farm-building install). For a limited company at 25% corporation tax, that's an effective 25% tax saving in the install year. Partnerships and sole traders benefit proportionally based on each partner's marginal tax position.

Asset finance. A bank or specialist lender provides the capital, the farm pays a monthly fixed amount, and the farm owns the system from day one. Whether the monthly saving on grid electricity exceeds the monthly payment depends on how much of the output the building uses; test it against the half-hourly data. Ask lenders what documentation they need and how long it takes.

Power Purchase Agreement (PPA). A third-party developer funds, installs, owns and operates the system on the farm’s roof or land, and the farm buys the generated electricity at an agreed rate for a fixed term. There is no capital cost to the farm; compare the agreed rate and term with the farm’s own tariff and with the capital routes. The terms are covered in PPA for farm solar.

Hidden and variable costs

Costs that sometimes catch farm clients out:

• G99 grid connection. Distribution Network Operators (DNOs) charge for studies and connection works, and the DNO quotes the fee directly; it rises with system size and where the network needs reinforcement. Ask for it in writing. See DNO grid connection for rural farm solar.
• Structural survey and engineering. Most farm buildings need a structural assessment that the frame can carry the added load; older buildings with no original calculations on file need more. See solar panel weight and roof loading on farm buildings.
• Scaffolding and access. Roof access by mobile platform or scaffold, with edge protection and, on fragile roofs, netting under the Work at Height Regulations 2005. The method is priced per building.
• Asbestos cement roofs. The biggest variable, and a roof decision before it is a cost: overclad, strip and re-sheet, or leave the roof alone and put the array elsewhere. See overclad or strip an asbestos cement farm roof.
• Three-phase upgrade. If the building only has single-phase supply, larger systems need an upgrade to three-phase that involves the DNO; the cost depends on the cable run and the DNO’s works.

A worked illustration from the official figures

Take a 50 kW roof, the top of the band the official statistics cover. At DESNZ's 2025/26 non-domestic mean of £1,167.29 per kW for 10–50 kW installations, the baseline is about £58,400 before the site-specific items above. At a yield of 900 kWh per kWp a year, which sits between the PVGIS figures for Cardiff (946) and Manchester (807) on a 10° roof, the array generates about 45,000 kWh a year. The saving is that generation multiplied by the unit rate on your last electricity invoice for the share used on site, plus the export rate on the rest; both come from your own bills and your own export tariff, which is why no generic payback figure appears here. Yields by region are on PVGIS yields for farm roofs by region.

Costs and returns in Scotland, Wales and Northern Ireland

The kit and labour cost little more or less across the UK: the DESNZ regional means above put Wales at £1,257 and Scotland at £1,321 per kW for 10–50 kW systems. The list has no Northern Ireland figure. What changes by nation is the return.

• Yield. PVGIS gives 946 kWh per kWp a year in Cardiff on a 10° south-facing roof, 828 in Belfast, 805 in Edinburgh and 734 in Inverness.
• Export. The Smart Export Guarantee applies in England, Scotland and Wales. Northern Ireland has no SEG: suppliers set their own rate, and Power NI publishes 11.88p per kWh for 1 October 2026 to 30 September 2027.
• Rates. Renewables plant is left out of rates valuation to 2035 in England, Scotland (SSI 2023/32) and Wales (WSI 2023/1229). In Northern Ireland plant up to 50 kW is not rateable; above that it is.
• Tax and VAT. These are the same everywhere: 100% Annual Investment Allowance on the PV plant, and 20% VAT on a business building, reclaimable if you are VAT-registered.

Grid rules differ too. Northern Ireland uses NIE Networks' G98/NI and G99/NI, set out with the funding position on solar on farm buildings in Northern Ireland.

How to work out your own numbers

A generic "£ per kW × system size" estimate is a starting point, not an answer. Two farms with identical roof areas deliver different economics depending on daytime baseload, the local network capacity, the roof's condition and the building's structure. The reliable route is a desk-based feasibility from half-hourly meter data: it yields a building-specific cost estimate, a generation forecast from PVGIS, a self-consumption ratio and a financial model. Installers should produce this before quoting, and the questions to put to them are on the farm solar installer checklist.

To scope a project yourself: take the half-hourly data from your supplier (or twelve months of invoices), the roof dimensions and orientation of each candidate building, and the official £ per kW figures above, and you have a defensible first estimate before anyone visits.