Solar Power Cuts Dairy Costs

A LUCINDALE dairy is saving up to 72 per cent on its water heating bill using an Australian Sun Energy solar hot water system.

More than six months ago, Doug and Lyn Crosby and their sons Bill and Bob installed a single-wall evacuated tube high-temperature dairy solar hot water system and, based on its performance, believe it will pay for itself in 2.5 years.

The custom-designed system is used to wash down their two robotic dairy machines and rinse-out milk lines.

The collector system that is mounted to the roof of the dairy comprises 32 single-walled vacuum glass tubes, each 2.2 metres long.

Inside the clear 100-millimetre diameter evacuated tubes are absorber fins coated with aluminium nitride selective coating to ensure high absorption of the sun’s rays.

Each of the 32 tubes are plugged into a heat exchanger which feeds into a 320-litre ground-based tank, pre-heating water up to 85C degrees for a 400L electrically boosted main storage tank.

The water is heated by the solar radiation collected by the tubes and can reach temperatures of up to 85C degrees depending on the time of the year.

An electric power booster in the main storage tank is used to reach the required temperatures to be used in the dairy, between 80C and 100C degrees.

With the latest investment, the Crosbys have continued their strong track record of innovation.

Four years ago, they were the first dairy in South Australia to install robotic milking machines to minimise labour needs. They are milking about 150 cows with the two Lely robots and continue to work part-time off-farm.

Doug says he was not immediately convinced about investing in the solar thermal hot water system.

“I couldn’t see how it was going to work but now we can see it does,” he said.

He is now a strong advocate of the Australian Sun Energy hot water system, and works out that by reducing power usage by about 30 kilowatts a day, you can make savings of about $10 a day.

Bill says it is a case of spending a little money to save some in the long term.

“If we can cut costs with our energy bill we can be more profitable,” he said.

“If we can take out or reduce a $60,000 expense it may allow us to pay ourselves a wage whereas, at the moment, we are not taking much out of the farm.”

Mount Gambier-based Australian Sun Energy, a locally owned company that operates across Australia, is a national distributor for Greenland solar hot water systems.

Sales manager Peter Taylor and business manager-director Roslyn Pasfield set up the company more than four years ago.

Their company now supplies energy reduction systems and equipment to domestic and commercial customers across the country. Their product range includes solar tracking skylights, pipe insulation, digital self-heating home systems and modular stainless steel water tanks.

Peter says the solar thermal hot water system will work on cloudy and sunny days. It even works when it rains and when there are frosts. These systems are also used in Europe, where it snows.

“There is always solar energy hitting the ground during the day,” he said.

“We are storing the energy from the sunlight in the water so it can even be used at night.”


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