A heat recovery programme on New Zealand dairy farms has huge potential to save power.
The Energy Efficiency and Conservation Authority (EECA) is offering subsidies to have heat recovery technology installed in dairy sheds. Heat generated during the milk-chilling process is harnessed and used elsewhere.
EECA selected four companies to install the equipment, including Oamaru-based Waitaki Refrigeration Ltd.
Information collected from the sheds where the system was operating has gone into a new online tool that shows farmers how efficiently they use electricity.
EECA projects and relationship manager Kirk Archibald said the average New Zealand dairy farm spent more than $20,000 a year on electricity. However, dairy sheds varied a lot in energy efficiency.
''Some dairy farms are using three times as much electricity as others for the same milk solids production.''
Overall, dairy farmers could save $42 million a year through cost-effective technologies and simple actions, he said.
''By answering a few simple questions, you can map your energy use against 150 dairy farms across New Zealand.
''You can find out how you compare against others, and the improvements that would make a difference in your milking shed.''
The country's 12,000 dairy farms use $251 million of electricity a year - 7% of the nation's total use. Electricity contributed about 15c to the cost of every kilogram of milk solids produced.
The heat recovery programme showed dairy sheds reduced electricity use by around a fifth after having the equipment installed. It would pay for itself in less than three years.
There were 37 farms taking part in the programme, with EECA offering advice as well as funding. Efficiency moves also included variable speed drives and vat insulation.
Mr Archibald said about half of the farms installing the technology were setting up new dairy blocks, with the rest being ''retrofitted''.
More farmers were being encouraged to join by applying for up to 40% of the cost of changes until June 30. Details are online at: www.eecabusiness.govt.nz/dairy-farms
- by Sally Brooker