A Dairy Farm's Solar Journey: Donnelly Farm, Cookstown

The Challenge: High Electricity Costs on a Working Dairy Farm

Dairy farming is an energy-intensive business. Milking parlours run for several hours each day, bulk tanks keep milk cool 24/7, water heaters provide hot water for cleaning, and various pumps and agitators operate throughout the day. For James Donnelly, whose 180-cow dairy farm sits on rolling countryside outside Cookstown, electricity was the single largest variable cost after feed.

"We were spending £800–£900 a month on electricity, and it kept going up," James explains. "The milking parlour alone accounts for about 60% of our total usage — the vacuum pumps, milk cooling, water heating, and lighting all add up. When Solar Tyrone suggested a ground-mounted array, I was interested but wanted to see the numbers."

The Installation: A Ground-Mounted Solar Array

Unlike domestic installations where panels go on the roof, agricultural installations often use ground-mounted frames. Solar Tyrone designed a 10kW system using 28 Jinko panels on a ground-mounted steel frame positioned to the south of the milking parlour. The location was chosen to minimise cable runs to the farm's consumer unit and to avoid any shading from nearby buildings or trees.

"The ground mount was actually easier than I expected," says James. "No scaffolding, no roof access issues. They drove the steel posts into the ground, bolted on the frames, and had the panels wired in two days. The system was commissioned and generating by the end of the second day."

The Results: Near-Zero Daytime Grid Import

After 18 months of operation, the Donnelly farm's solar system has delivered consistently impressive results:

• Annual generation: 8,800 kWh
• Annual consumption offset: Approximately 85% of daytime farm electricity
• SEG export income: £150 per year
• Annual bill reduction: From £10,200 to £3,400 — a saving of £6,800 per year
• Payback period: 4.8 years (system cost £10,500 after SEG income)

"The ROI projection Solar Tyrone gave us at quote stage has been accurate — we're on track for a 5.5-year payback, which is actually better than they promised because electricity prices went up again," says James.

Why Solar Works So Well for Dairy Farms

Dairy farms are uniquely suited to solar energy because their electricity demand is concentrated during daylight hours. Milking typically happens in the early morning and late afternoon, with peak consumption during the day for milk cooling, water heating, and cleaning. This aligns perfectly with solar generation patterns, meaning a very high percentage of generated electricity is consumed directly on-site.