Energy savings: Ngahinapouri farmer Dave Camp, left, has the solar system explained to him by company owner Jeff Stack. Photo: MARK TAYLOR

A Hamilton man is pushing solar water heating for farms which he says makes savings of thousands of dollars.

A former Hamilton sparkie is turning the Waikato sun into savings for dozens of dairy farmers around the region and it's all thanks to a few pretty warm tubes of glass.

Jeff Stack, director of the Solar Commercial Company, is starting to gain momentum with his solar panels, which ''super-heat'' water through glass tubing even on chilly days.

More than 38 farms around the Waikato have installed the Solar Commercial system, with expansion plans already in place to grow into the South Island. The system is based on the process of glass tubes ''super-heating''. The 1.8 metre glass tubes heat up from 25 degrees Celsius to 360C thanks to sun power. This occurs even on cloudy or overcast days, with aluminium foil assisting the heating process.

The hot water then travels through the tubes into the storage tank above, heating the water from 14C to 85C.

That water is then pumped into the hot water cylinder, which is in turn dumped at 38C.

This is where the saving itself occurs the farmer will not have to heat his hot water cylinder to a higher temperature, as the panels have already done this for him.

Around half of a farm's power usage comes from its hot water usage, Mr Stack said.

He produces two separate solar heating schemes for farms. The overhead system can be easily moved, making them ''good for sharemilkers to buy'', while a pumped system features the solar collectors, a controller and pump, but no storage tanks, meaning the collectors can easily placed on cowshed roofs.

The Solar Commercial Company is in partnership with Tp-Solar, a Chinese company and the world's third largest solar manufacturer. Mr Stack hosted one of the company's engineers in New Zealand in 2009, to help design units to cope with New Zealand's unique weather issues.

Ngahinapouri dairy farmer Dave Camp was one of the first to have the system installed two years ago, and he said he hadn't looked back.

Mr Camp, who runs 140 cows in a 12-a-side herringbone, reckons he makes a saving of around $2800 a year thanks to the solar heating tubes.

''It's really nothing to do with being green either,'' Mr Camp said. ''This is good business.'' Last year he saved more than 19,000 kW/hecatres energy thanks to the system.

Savings ranged from 87 per cent per month in the summer months to 77 per cent in the winter months.

In addition, Mr Camp said he hasn't had to do any running repairs since they were installed.

Mr Stack said the more panels, the higher the savings. He installed nine on a Taranaki shed last year, which lately has been recording massive energy savings.

''The bigger the shed, the bigger the payback,'' he said.

Mr Stack believed that the domestic potential for the solar tubes was there as well, with a large portion of energy on a domestic bill being used up by heating water.

He will exhibit the systems at the upcoming National Agricultural Fieldays and is hoping his product will catch the eyes of a few older cockies.

''It's the younger farmers who are more pro-active these days,'' he said. ''Instead of wanting to buy the new Holden Commodore and the new tractor, they've got bigger debts and know they have to look hard at savings to make it.'' *