Innovative energy efficiency on North Otago dairy farm
The county’s largest hydro-electric generator has reduced power-usage at a dairy farm it owns near Kurow in North Otago
by around 27 percent as a result of innovative Kiwi technology.
“Meridian Energy is leading by example and showing what can be done in terms of energy efficiency on a typical New
Zealand dairy farm,” says Alan Seay, spokesman for Meridian Energy.
Dairy farms are significant electricity users as a result of the high-capacity vacuum pumps used to drive the milking
units. In addition to this is the big demand for hot water to clean the milking equipment and shed after each milking.
Two of the three energy efficiency solutions were found in previous years during visits to the Mystery Creek Fieldays.
, Meridian’s Rural and Business Segment Manager, says the team that went looking for ideas at Fieldays found two very
innovative Kiwi-designed energy efficiency products that could be used on its Kurow dairy unit.
“New Zealanders have a great reputation for being innovative and trying to find better ways to do things. We have taken
three ideas and applied them in a commercial dairy operation.”
Varivac, one of the solutions used at the Kurow farm, is a computer device that provides accurate control of the large
electrical pump that drives the milk-shed vacuum pump. This means the pump only works as hard as needed to provide the
required vacuum, which varies constantly as cows are put on and off the system. The pump, which used to run continuously
at 15kW, now runs at an average of 4.5kW, a 75% reduction in power usage.
Mahana Blue, developed by Danfoss NZ, is the second innovative product Meridian installed in its Kurow dairy-shed. It
takes waste heat from the milk and uses it to heat water to 85C, which is then used to clean the equipment and the
milk-shed.
The third innovation used is a grounded copper ring installed around the milk-shed rotary bale. This has eliminated the
stray voltage that previously occurred across the shed, and which was high enough for some cows to detect.
“Not only has energy consumption at the farm been cut by nearly 30 percent, the quality of the milk has improved, and
the time taken to milk the cows has been halved,” says .
“These technologies have the potential to reduce energy usage and improve profitability at dairy farms all around New
Zealand. We are very pleased that Meridian has been able to use its resources to demonstrate practical energy efficiency
measures for the agricultural sector,” concludes .
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