Solar panels for dairy farms: matching the array to the milking and cooling load
Solar panels for dairy farms are sized against the electricity the farm uses in daylight. A dairy's demand comes from bulk-tank cooling, the milking parlour, vacuum and milk pumps, plate coolers, water heating, scrapers and lighting. The part of that demand that falls in daylight is the part solar meets directly, and it is worth more than exported power because it replaces electricity bought at your tariff. This site is built around the dairy load profile rather than around farming in general.
Why a dairy load suits solar
Unlike a seasonal building, a dairy uses electricity every day of the year. The Dairy Group's study of UK dairy farms, reported by Farmers Weekly in 2014, found cooling, water heating and vacuum pumps each took roughly 25 to 30% of a dairy's electricity. How much of that falls in daylight depends on the milking times: a herd milked early in the morning and late in the afternoon has its cooling and hot-water peaks at the edges of the solar day, while a robotic herd spreads the load across 24 hours. A system that can run part of the parlour and the tank from the roof during the day leans less on the grid connection, which matters on a constrained rural network.
How a dairy system is sized
Sizing starts from annual use and the shape of the milking day. A 100-cow herd at 400 to 600 kWh per cow uses 40,000 to 60,000 kWh a year (AHDB and NFU Energy, 2021). At about 950 kWh per kWp a year, a round figure inside the PVGIS range for England, an array of roughly 42 to 63 kWp would generate that much over a year. Treat that as a ceiling, not a target: a dairy cannot use all of a large array's midday output, so the array with the best return is usually smaller, and the right size comes from half-hourly meter data. For other herd sizes, read what size solar system for a dairy farm; for the sources behind the kWh-per-cow figures, read how much electricity a dairy farm uses.
Costs and tax relief
We do not publish a price list, because cost depends on the roof, the size and the grid connection. For scale, DESNZ's 2025/26 cost data gives a mean of about £1,257 per kW for 10 to 50 kW systems in Wales (a mean that includes domestic installs); larger rooftop systems usually cost less per kW, so ask for itemised quotes. Solar PV counts as plant and machinery, and the £1 million Annual Investment Allowance usually means 100% relief in year one for a business under the limit; the tax you save depends on your tax rate and profits. Above the allowance a company can claim a 50% first-year allowance on solar as special-rate plant (full expensing does not cover solar). The Smart Export Guarantee pays for exported surplus: the best open fixed rates we found in early October 2026 were around 12 to 13p per kWh, and small suppliers paid 3 to 6p. Avoided import is worth more than exported surplus. Our dairy farm solar panel cost guide and dairy farm solar calculator go through the numbers.
Funding routes for dairy solar
The routes that apply to most dairy farms are the Annual Investment Allowance and the Smart Export Guarantee. In England, the Farming Equipment and Technology Fund 2026 closed on 12 May 2026 and Capital Grants 2026 has closed, and the Sustainable Farming Incentive pays for land management rather than for panels; none of the GOV.UK pages we read in October 2026 listed solar PV. Wales and Scotland run separate schemes, and we have not confirmed what is open there. The dairy farm solar grants page lists each route with its status and the date we read it.
Compliance and sector considerations
What needs care is the install itself around a live working dairy: the installer has to work around slurry pit and silage clamp electrical safety, keep cabling clear of washdown and acid-wash areas, and schedule around calving rather than through it. In England, rooftop solar on a farm building is generally permitted development under Class J of Part 14 of the GPDO 2015, not the householder Class A: up to 50 kW is permitted subject to the Class J limits, and above 50 kW the council makes a prior-approval decision on design and appearance, including glare. A listed building falls outside Class J and needs planning permission and Listed Building Consent. In Wales, solar PV on a non-domestic building falls under Part 43, Class A of the Welsh general permitted development order, and in Scotland under Class 6J of the Scottish order; each has its own limits and exclusions, so check the rules for your building before relying on permitted development. The most common blocker is the roof itself. Many pre-2000 farm buildings have asbestos cement sheeting, so an asbestos survey comes first, and the roof is often over-clad or replaced before panels go on. Under the Control of Asbestos Regulations 2012, careful removal of asbestos cement sheeting is generally non-licensed work (HSE), but it still needs a risk assessment, trained workers and controls. A G99 grid application is needed above 16 A (3.68 kW) per phase, and rural networks are often capacity-constrained, so the connection is usually the long pole of the project and is best started from day one. When comparing installers, ask for their MCS certificate number and check it on the MCS database, and check NICEIC, RECC and TrustMark membership with the issuing bodies. SEO Dons Ltd publishes this site and does not install.
Where to go next
Start with what size solar system for a dairy farm, then check dairy farm solar grants, the dairy farm solar panel cost guide and the dairy farm solar calculator. To know your herd's electricity use first, read how much electricity a dairy farm uses. When you are ready, send an enquiry and we reply by email, or read the dairy solar FAQs first.
