Practical guidance for solar on farms

With energy costs rising and farms looking to strengthen their resilience, interest in solar, and solar + battery continues to grow. Understanding the technology and how to incorporate it into your farm takes time, which is why DairyNZ and the Energy Efficiency and Conservation Authority (EECA) are working together to provide dairy farmer‑focused guidance on solar and battery storage.

Why solar on-farm

Solar can work on any farm, anywhere, but it’s especially useful on dairy farms. With energy use high and power costs rising, many farmers are looking for ways to cut overheads and boost resilience – making solar paired with batteries a smart option.

Solar system costs have fallen significantly, with typical payback now around 4–6 years, compared with 10–12 years just a few years ago. A well‑designed setup can deliver real savings, and in some cases, farmers can cut electricity bills by up to 70%. As with feed, using what you produce on‑farm is best, and maximising your own solar generation, rather than selling back to the grid, tends to be the most profitable approach.

“Solar is a compelling option when it’s integrated well,” says EECA specialist Chris McArthur. Generation peaks in the middle of the day, so farmers get the best returns when they use that power on-site – especially for water heating, milk cooling, and shed services.

Battery storage can boost savings and add resilience

Paired with solar, batteries store excess energy for use during morning and afternoon milkings, cutting reliance on the grid and keeping critical services running during outages.

In areas with unreliable rural electricity, an adequately sized battery can provide real backup during storms or power outages. Demonstration farms show that on‑farm solar and batteries can even support full or partial off‑grid operations for several days when needed

Panel location and orientation, inverter sizing and installer experience all influence system performance.

Well‑planned solar and battery systems can cut costs, support day‑to‑day operations, and give farms extra resilience when it’s needed most.

Benefits

Lower electricity bills and reduced exposure to volatile energy prices
Improved resilience, especially when solar is paired with batteries
Reduced emissions and stronger control over farm energy use

Considerations

Batteries increase up‑front costs, so timing of use and system design matter
Payback depends on matching system size to energy use and understanding local pricing conditions

Thinking about solar?

Know your current energy use – establish where and when power is consumed
Choose the right-sized solar and battery storage to maximise on‑site consumption.

Learn more at dairynz.co.nz/solar-power

Lessons from Fairbank Farms

Southland Michael Farmer and Chris Stewart adopted solar and batteries early, aiming to boost resilience and environmental performance. Their 800‑cow farm near Drummond ran for three days without grid power during a Southland wind event last October, allowing them to continue with milking, cooling and effluent management without generators.

Electricity use has dropped by around 60%, with an estimated payback of four to six years. These results reflect wider evidence from EECA’s demonstration programme, showing strong returns when solar systems are tailored to a farm’s energy profile.

Watch their video and read more at dairynz.co.nz/eeca