Some dairy farmers could cut their electricity bills by up to 20 per cent, says a Massey University study.
Research by Professor Ralph Sims and doctoral student Karl Hartman has shown most farms could reduce their peak load, cutting their bills.
The researchers found from records kept by more than60 dairy farmers that energy consumption rates were generally higher on smaller farms.
Farms with the largest herd size and largest annual production had lower energy inputs a hectare, leading to the conclusion that an increased scale of operation was more energy-efficient.
Three intensive case studies of low, high and moderate energy-consuming farms identified opportunities for cost-cutting and energy-saving, the researchers said.
Heating water and maintaining the temperature, cooling milk and maintaining the temperature, and operating the vacuum and milk pumps during milking used the most electricity.
Cost-effective methods to reduce consumption included insulation of hot water cylinders and milk vats; use of heat exchangers for pre-cooling milk and pre-heating water; better matching of hot water cylinder size and vacuum pump size to the respective demands; use of variable speed vacuum pumps; and just-in-time heating of the hot water.
The research paper, co-written by Mr Hartman and Professor Sims, also recommended ways to reduce energy consumption at a national level.
These included development of a set of benchmarks for on-farm energy consumption and costs to help farmers decide which operations were the best investments for spending on energy efficiency.
Detailed breakdowns of electricity use profiles would make it easier for the farmer to consider measures such as the installation of solar water heating.
And evaluation of commercial energy-saving systems, technologies and equipment would mean those giving practical energy-saving benefits could be recommended.
