Solar Panels for Dairy Farms in Ireland
Dairy farms are one of the strongest cases for commercial solar in Ireland. Milk cooling, vacuum pumps and plate coolers draw heavy power during the morning and evening milkings, and large south-facing shed roofs give you the space to cover it. The TAMS 3 Solar Capital Investment Scheme pays up to 60% of the cost on systems up to 11 kWp, which makes the payback faster than almost any other building type. Compare quotes from installers who work on farms.
Fact-checked by John Rooney, Solar Energy Editor. Editorial policy
Quick Answer
Most Irish dairy farms install 11-100 kWp of rooftop solar, with 11 kWp the sweet spot under TAMS 3 (planning-exempt and up to 60% grant on agricultural buildings). Sized to milk cooling and vacuum pump loads, an 11 kWp system costs roughly €9,000-€11,000 before grant, can fall to around €4,000-€5,000 after TAMS 3, and typically pays back in 4-7 years.
Why solar suits dairy farms
A dairy farm has two things that make solar PV work well: a big daytime electrical load and a lot of roof. Milk cooling runs straight after each milking, the vacuum pump runs throughout, and plate coolers, water heating and washing all draw power in the same windows. That demand lines up closely with when panels generate, so a well-sized array is mostly self-consumed rather than exported, and self-consumption is where the money is.
The load profile is the key. Irish dairy farms typically show two clear peaks: a morning milking peak and an evening milking peak, with the bulk cooling tank pulling power after each. Solar covers the daytime portion of these loads directly. The morning peak often starts before the sun is high and the evening peak runs into dusk, which is where a battery or a hot-water diversion device helps shift surplus midday generation into the milking windows.
Roof space is rarely the constraint. A modern milking parlour, cubicle shed or storage building gives a large, unshaded, often south or east–west facing roof, far more than a house. That means you can size the system to the load rather than to the available area. For the wider picture across all farm types, see our farm solar guide.
Milk cooling
Bulk tank refrigeration is the single biggest load on most dairy farms and runs right after milking, in daylight hours.
Vacuum & plate cooling
Vacuum pumps run throughout milking and plate coolers cut cooling demand, steady daytime loads solar covers well.
Water heating
Wash-up water heating is an ideal home for surplus midday generation via a hot-water diversion device.
What size solar system does a dairy farm need?
Most Irish dairy farms install between 11 and 100 kWp. 11 kWp is the headline figure because it is the ceiling for the TAMS 3 grant and stays planning-exempt on an agricultural building, so it is the default starting point for a herd of roughly 80–150 cows. Larger herds, robotic milking or significant water heating can justify 30–100 kWp, though above 11 kWp you move from TAMS 3 to the Non-Domestic Microgen Grant and may need planning for the part over the exemption cap.
| Herd Size | Typical System | Panels (approx.) | Annual Generation | Best Grant Route |
|---|---|---|---|---|
| Up to 80 cows | 6–11 kWp | 14–26 | ~5,000–9,500 kWh | TAMS 3 (up to 60%) |
| 80–150 cows | 11 kWp | ~26 | ~9,500 kWh | TAMS 3 (up to 60%) |
| 150–250 cows | 20–50 kWp | 46–115 | ~17,000–43,000 kWh | NDMG |
| 250+ cows / robotic | 50–100 kWp | 115–230 | ~43,000–86,000 kWh | NDMG |
Generation assumes the average Irish yield of around 860 kWh per kWp per year. Actual figures depend on roof pitch, orientation and shading. A site survey and a year of meter data give the accurate sizing, oversizing past your milking load just pushes more cheap export rather than displacing import.
Dairy farm solar grants, ACA and payback
For dairy farms the headline grant is TAMS 3, not the standard SEAI grant. The TAMS 3 Solar Capital Investment Scheme funds up to 60% of the cost of on-farm solar up to 11 kWp (the higher rate applies to eligible young trained farmers and partnerships; the standard rate is 40%). Systems within that 11 kWp cap are planning-exempt on agricultural buildings, and TAMS support stacks with the Clean Export Guarantee for any surplus you do export.
Above 11 kWp the TAMS 3 cap is exceeded, so larger arrays use the SEAI Non-Domestic Microgeneration Grant (NDMG) instead, which runs up to a maximum of €162,600 on large systems. You apply under one scheme or the other, not both, so the size you choose drives which grant fits.
| System | Gross Cost (est.) | Grant Route | Net Cost (est.) | Payback |
|---|---|---|---|---|
| 11 kWp | €9,000–€11,000 | TAMS 3 (40–60%) | €4,000–€6,600 | 4–6 years |
| 30 kWp | €24,000–€30,000 | NDMG (€9,000) | €15,000–€21,000 | 5–7 years |
| 50 kWp | €40,000–€55,000 | NDMG (€12,000) | €28,000–€43,000 | 5–7 years |
| 100 kWp | €70,000–€100,000 | NDMG (€22,000) | €48,000–€78,000 | 6–8 years |
Installed cost on farms runs roughly €800–€900 per kWp at commercial scale, with smaller TAMS-capped systems at the higher end per kWp. Figures are estimates for 2026 and exclude battery storage, which is not covered by NDMG.
Accelerated Capital Allowance
Farms trading as a company can claim the Accelerated Capital Allowance (ACA), writing off 100% of qualifying solar and battery cost against profits in year one through the Triple-E register. Sole-trader farms should check the available capital allowances with their accountant.
Where the savings come from
Commercial electricity costs around 22c/kWh to import while exported surplus earns roughly 18c/kWh, so displacing your own milking load is worth more than exporting. Dairy farms with strong daytime demand reach 80–90% self-consumption, which is why the returns are strong, typically a 10–15% annual return.
Roof, planning and install specifics for dairy farms
The practical details on a dairy farm differ from a warehouse or office. Plan for these before you commit to a system size.
| Factor | What to check on a dairy farm |
|---|---|
| Roof structure | Older sheds may have light-gauge purlins or fibre-cement sheeting; an installer should confirm the roof carries the panel and mounting load before fixing. |
| Planning | Up to 11 kWp on an agricultural building is planning-exempt under the rooftop exemption; larger arrays or ground-mount may need permission. |
| Load matching | Milking peaks are morning and evening; a battery or hot-water diversion shifts midday surplus into those windows to lift self-consumption. |
| Grid connection | ESB Networks NC6 covers smaller systems and NC7 covers larger ones up to 200kW; inverters must meet EN 50549. |
| Orientation | East–west shed roofs spread generation across both milkings, which can suit dairy load better than a single south-facing pitch. |
Battery or hot-water diversion?
Because milking peaks fall either side of midday, surplus generation at noon is common. A hot-water diversion device is the cheapest way to soak it up by pre-heating wash water. A battery costs more but can shift power into the early-morning and evening milkings and into the bulk tank cooling cycle. Which makes sense depends on your milking times and tank schedule.
Dairy Farm Solar FAQ
How big a solar system does a dairy farm need?
Most Irish dairy farms install 11-100 kWp. An 11 kWp system suits herds of roughly 80-150 cows and is the cap for the TAMS 3 grant while staying planning-exempt on agricultural buildings. Larger herds, robotic milking or heavy water heating can justify 30-100 kWp under the NDMG grant. Sizing should be matched to your milk cooling and vacuum pump loads, ideally using a year of meter data.
What grant can a dairy farm get for solar panels?
The headline grant for dairy farms is the TAMS 3 Solar Capital Investment Scheme, which funds up to 60% of on-farm solar up to 11 kWp (40% standard rate, with a higher rate for eligible young trained farmers and partnerships). Above 11 kWp, farms use the SEAI Non-Domestic Microgeneration Grant (NDMG) instead, up to a maximum of €162,600. You apply under one scheme, not both.
Does an 11 kWp dairy farm solar system need planning permission?
No. Rooftop solar up to 11 kWp on an agricultural building is planning-exempt in Ireland, which is why 11 kWp is the common starting point for dairy farms. Larger arrays beyond the exemption cap, or ground-mounted systems, may need planning permission. Your installer should confirm the exemption applies to your specific building.
Will solar cover the milk cooling and vacuum pump load?
Solar covers the daytime portion of milking loads directly, and milk cooling runs straight after milking in daylight hours. Because morning and evening milking peaks fall either side of midday, a battery or a hot-water diversion device helps shift midday surplus into the milking windows. Dairy farms with strong daytime demand typically reach 80-90% self-consumption.
What is the payback on solar panels for a dairy farm?
An 11 kWp system costs roughly €9,000-€11,000 before grant and can fall to around €4,000-€6,600 after TAMS 3, giving a payback of about 4-6 years. Larger NDMG-funded systems typically pay back in 5-8 years. Payback is driven by self-consumption, since displacing import at about 22c/kWh is worth more than exporting surplus at about 18c/kWh.
Related Guides
Sources
- SEAI, Non-Domestic Microgen Scheme (NDMG)
- SEAI, Accelerated Capital Allowance
- ESB Networks, Micro and Small-Scale Generation
Last updated: June 2026
John Rooney is the founder of Solar Info and has been covering the Irish solar energy market since 2023. He fact-checks all content against official SEAI data and maintains relationships with SEAI-registered installers across Ireland.
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