Solar on stilts for cattle grazing

In late May, the Country Women's Association of NSW passed a motion by a two-thirds majority calling on governments not to allow solar farms in prime agricultural areas.

There is the possibility the CWA could qualify that stance. After last week being made aware of projects that allow for pasture renovation and grazing with cattle, CWA NSW president Stephanie Stanhope said members' main concerns were the incompatibility of cropping and solar systems.

"If agriculture can continue to be done in some other way or you could incorporate the both of them, I think that'd be a win-win but broadacre, I think, is out because that machinery just would not manoeuvre around anything," Ms Stanhope said.

The reality is that one in three solar farms larger than 5 megawatts already have sheep grazing the pastures beneath them, according to a soon to be released Clean Energy Council survey

but most are too close to the ground for access by cattle and tractors.

Right now, though, a carefully-designed installation by Wynergy at Farrer Memorial Agricultural High School near Tamworth is underway.

The 60 kilowatt system is made up of two 43-metre-long rows of solar panels that are each about 4m wide and spaced about 15m apart. It will replace three diesel irrigation pumps.

The school's Illawarra dairy cows and stud Angus cattle will graze beneath the solar panels as they track the sun atop ultra-high supports.

Wynergy co-owner Ben Wynn described the installation as a prototype that could pave the way for cattle graziers and dairy farmers to integrate solar into normal farm operations.

"We wanted to show farmers around regional Australia that there was a way to build systems that didn't need fencing off and that would provide shade for stock," Mr Wynn said.

The beam height is 3.6m, and the minimum height, when the panels are swung down to face the setting sun, will be 2.4m.

"There'll be plenty of room, hopefully, for a cow or steer or whatever to jump up on top of someone else and carry on the way they do," Mr Wynn said.

Mr Wynn says the design costs about 30 per cent more than comparable lower systems but the $140,000 investment is forecast to break even in just five years.

Farrer Memorial Agricultural High School farm supervisor Andrew Eather says the students will study the way the cattle interact with the solar panels and the productivity of the paddock.

"We get to showcase new technologies to the farmers of tomorrow," Mr Eather said.

"Because it's elevated, we don't lose paddock space apart from where the pylons go, and we think country getting shaded actually might help us, particularly in the summertime."

The paddock was sown with a subtropical permanent pasture last season in anticipation of the installation and Mr Eather believes pasture renovation will still be feasible once the system is in place.

"I can drive straight underneath it with a tractor, so all we've got to do is negotiate the pylons and sow in between, it's not a big issue," he said.

Further south in Victoria, Squires Winery has also found a way to integrate solar and agriculture with a tracking system 2.4m above the ground. With photovoltaic surfaces on each side of the panels, the Australian-designed system boasts maximum efficiency.

The 100kW system occupies about 400 square metres of the 42 hectare property, owner Paul Squires said.

"It takes up a very, very small portion of our land, you can graze sheep under it and, in terms of revenue, it's as good as any agricultural product, in fact, quite a lot better," he said.

Dovetailed with agriculture and dotted across the country, small solar farms could play a vital role in powering Australia, Meralli Projects executive director and environmental psychology academic Dr Methuen Morgan said.

Solar farms that take up 5 to 15ha of land and supply around 5MW each could, he said, feed into the medium-voltage network, reducing the need for high-voltage transmission lines.

"If you were to multiply 5MW across 10,000 substations around NSW, that's almost enough power during the day to power the eastern seaboard," Dr Morgan said.

"More importantly, we're talking about little parcels of land that can fit in a property without taking up all the productive land.

"They dovetail perfectly together and provide an opportunity for the owner of the solar farm to offset and supplement their income."

Any move to ban solar farms on prime agricultural land should be resisted, Narromine broadacre farmer and National Renewables in Agriculture Conference and Expo convenor Karin Stark said.

"The decision of what to farm on your own land should be up to that farmer," Ms Stark said.

"It's about ensuring that neighbours aren't impacted too much and also that they're compensated or there are benefits that are shared with them and local communities.

"Calling for a ban on large scale renewables is taking away a business opportunity for a farmer to earn secondary income that flows on to local economies."