In Southland a typical 50-bale dairy shed using 60 to 70 per cent of its energy for water heaters, the milk chiller and the vacuum pump could be designed and built much more efficiently, a Venture Southland workshop was told.

Venture Southland enterprise project manager Robin McNeill said a study by the Centre of Advanced Engineering assessed five Southland farms and analysed plant layout and data from 15 other farms.

"The researchers found that many farmers overlooked the most immediate cost-saving measure, which is to use night-rate electricity," he said.

"Farmers could make some easy gains on water heating by minimising hot water use, adding thermal insulation, checking thermostat settings and preventing drips and leaks."

Centre of Advanced Engineering dairy project manager Warren Gregory said the study had identified several related issues that merited further investigation.

One of the most promising items of equipment was a heat pump designed for use in dairy sheds, which could heat water to 85C using heat recovered from the milk vat chiller.

Savings of about $1800 a year on large farms could pay the cost of the unit in less than six years.

Source: New Zealand Herald