Dairy farmers can save $30,000 on milk chilling costs
Dairy farmers can avoid paying $30,000 on a pre-cooling system and comply with new regulations by insulating their milk vats instead, government agency Energy Efficiency and Conservation Authority (EECA) says.
EECA has launched an online tool allowing farmers to calculate how insulating their milk vat can help save on energy costs.
By August this year any new or upgraded dairy farm must have milk chilled to 6 degrees Celsius within two hours of milking, under Primary Industries Ministry rules.
Existing farms have until July 2018 to comply.
EECA project manager Kirk Archibald said one, cheaper alternative in today's cash-strapped times was to insulate the milk vat.
Depending on the size of the vat, the cost varies between $1850 and $3750.
However, some of these costs can be clawed back because energy savings range between $200 and $1000 per vat per year.
Archibald said the amount of savings depended on a number of factors including electricity price, farm location, vat size and shape, efficiency of the refrigeration system, and how long milk was in the vat.
He said about 80 per cent of milk vats on farms were uninsulated, wasting up to $7 million of electricity and emitting around 4000 tonnes of CO₂ more per year than they could be. This is equivalent to the energy consumption of around 3000 households and the CO₂ emissions of 1800 cars.
"New Zealand dairy farms use around 180 gigawatt-hours of electricity per year to store milk at a safe temperature – that's the same electricity use of about 25,000 households."
"Insulating a milk vat protects it from heat gain, reducing the load on a farm's refrigeration system and the amount of time needed to cool milk. Farmers can save up to 6 per cent of their dairy shed energy consumption and around 40 per cent of the energy used for refrigeration, and in summer months vat insulation can speed milk chilling by up to 20 per cent," Archibald said.
Manawatu dairy farmers, Allison and Trevor Martyn, experienced the benefits of vat insulation on their Rongotea farm.
When they started farming in 1998, they noticed during their first summers the chiller unit cutting in and found their shed power bills excessive - until they wrapped their vat.
"I think we probably reduced our power bill by about a third," Allison Martyn said.
"We noticed once you get the milk down to temperature the wrap seems to keep it there and you hardly hear the chiller cutting in and out between milkings. For the cost of the wrap it's been worth its weight in gold.
She says another benefit of insulation is they no longer have trouble with the heat resistant bacteria thermodurics.
EECA's new milk vat insulation tool is being showcased at a series of DairyNZ's MilkSmart events being held around the country at present. Farmers can register to attend these events at www.dairynz.co.nz/milksmart.