Solar panels slash Waikato farmer’s power costs

An aerial view of Malcolm Jones’ fully solar-powered dairy shed. Photos / Clint Lawson / Muse3D

A sunny summer has paid dividends for a Waikato farmer.

Malcolm Jones’ milking shed at Te Poi, near Matamata, is entirely powered by solar panels.

Running 600 cows on 200ha, Jones “started talking” to Supreme Solar director Sam Mathis at last year’s NZ Dairy Expo in Matamata.

He said he had been thinking about the project two years prior. Cost-saving was the key driver.

An on-farm visit by Sam Mathis followed, along with an analysis of the farm electricity costs.

“It was built around the power bill,” Jones said.

Most farmers venturing into solar usually install 70 to 80 panels initially, but he decided to cover the entire roof of his 54-a-side rotary milking shed.

The 380 panels, which went “live” last September, can produce up to 100 kilowatts of electricity during sunlight hours.

Jones said his previous power bill for the milking shed, along with associated electrical equipment relating to effluent disposal, water supply and milk chilling, was around $3800 a month.

“For the last four months, it has been nothing.”

He said the transition to solar was seamless, involving grid approval and installation of a solar inverter, which converts DC to AC power.

Mathis said although efficiency dipped in winter or cloudy weather, New Zealand’s climate still allowed significant yearly energy generation.

Excess energy can be fed back into the grid or stored in solar batteries, benefiting the five houses on the Jones’ farm.

Environmental benefits

Matamata dairy farmer Malcolm Jones said the transition to solar was seamless. Photos / Clint Lawson / Muse3D

Jones, who has been living at Te Poi for 25 years, said there were also environmental issues to consider, as well as cost savings when making the move to solar.

“It’s a cleaner, free form of power that can yield a return on investment for the farm.”

Mathis said solar was also a way to improve the business at large.

“Farmers are using solar as a means to increase the long-term value of their properties - a farm that’s self-sufficient and producing clean energy will likely be attractive to tomorrow’s buyers.

“Solar helps promote the image of an eco-smart farm that helps to preserve the New Zealand environment.”

Supreme Solar director Sam Mathis, left, with Te Poi farmer Malcolm Jones. Photo / Steve Edwards

Overall, he said the move to solar promised long-term financial returns as the installations have a 30-year life while enhancing the farm’s “eco-friendly” image.

Mathis said every farm was different, so there was no one-size-fits-all system that would work for every dairy farm.

As far as the placement of the solar panels, several options exist.

Mathis said normally, panels could be installed on the roof of a farm shed.

“If the shed is not ideal, another possibility is a ground-mounted system, which offers very similar benefits to rooftop solar.

“Tilt frames can be added, which place panels at just the right angle to receive direct sunlight.”

Resource consents from the respective local authority are required for ground-mounted panels, but not for roof installation.

Jones is in his 12th season milking in the rotary shed following an amalgamation of four smaller farms.

With three staff, he has milked all year-round “for financial return” for the past eight years.

Milkings are at 4am and 12.30pm, freeing up staff in the afternoon.

Young stock are grazed on a 45ha block near the home farm.

Waikato installations

An aerial view of Malcolm Jones’ fully solar-powered dairy shed. Photos / Clint Lawson / Muse3D

Agri-solar provider Rural Energy said it had completed 300 installations in the Waikato, and 1000 were projected over the next three years.

Rural Energy chief executive Shaheer Azizi predicted this would extend to 3000 to 4000 across New Zealand in the same period.

By switching to solar, customers could reduce the carbon footprint of their farm and save money, he said.

“Energy usage on dairy farms has grown over the past 20 years due to use of automated equipment.

“It is now estimated that electricity contributes 15c to the cost of every kilogram of milk solids produced.”

Rural Energy has entered into an agreement with Farm Source to help “push out” the initiative, with all Fonterra farmers given an option to purchase on-farm solar through their Farm Source store account.

Crown-owned New Zealand Green Investment Finance last year provided a $10 million credit facility to Rural Energy to finance “solar as a service” power purchase agreements for dairy farms in New Zealand.

NZGIF said it had invested around $50 million into several companies, including Rural Energy, that are helping New Zealand farms to decarbonise.

Information provided by NZGIF showed that the agricultural and energy sectors account for almost 90% of New Zealand’s greenhouse gas emissions.

“Options available for farms to reduce emissions have been limited, but that is starting to change due to increasing farmer demand for sustainability solutions.”