By Debbie James

Capturing energy produced from cooling milk is generating an income for a Welsh dairy farm and reducing its electricity costs.

Jackie Mountford and her sons, Gary and Stuart, milk 200 cows at Lower Heldre, a 350-acre holding near Buttington, Welshpool.

Upgrading the bulk tank became a priority to capitalise on the free transport incentive offered by their milk buyer, Arla, for every-other-day collection.

But the family has gone a step beyond increasing capacity – they invested in a system that would not only allow energy to be reused on the farm but would provide an income from the Renewable Heat Incentive (RHI).

Their Xchanger, a glycol chiller that transfers heat captured from the milk during cooling and increases the temperature into usable heat, creates energy to heat water and buildings and pays their business 9.5p for every kilowatt hour of that energy used on the farm.

Milk is chilled to between 3-4C before it enters the 16,000 litre milk tank compared to 20C under the previous system.

“Our old tank had to overwork to drop the temperature from such a high point, it would be running for six to seven hours a day. Now it only runs for an hour during milking,’’ Stuart explains.

With milk cooling and water heating accounting for the biggest proportion of energy use on dairy farms – AHDB Dairy estimates that the average dairy farm uses between 200kWh and 400kWh of electricity per cow per year – Stuart says the savings are potentially significant.

“The unit has only been installed for a month so we don’t know what the actual savings will be but we know that it uses about a third of the energy it takes to run an older DX system. Not only that but we get the Renewable Heat Incentive tariff too.’’

The Mountfords reckon the system will pay for itself in under five years, which includes the £6,000 a year they were paying to have their milk collected every day.

It is not the first renewable energy system on the farm – there is an 80kW biomass boiler which heats the farmhouse and the milking parlour and there are solar panels on the parlour roof.

But there is one notable advantage with the Xchanger says Jackie. “You have to feed wood into the biomass boiler but with the chilling system the milk is always there.’’

The family has been farming at Lower Heldre since 1955, initially beef and sheep but converting to dairy in 1993.

Jackie’s late husband, George, who passed away in 2007, had always had a hankering to milk cows so they took the plunge, stocking the farm initially with 100 cows and installing a secondhand 9:18 direct-to-line herringbone parlour. Five years ago they upgraded to a 24:48 rapid exit Dairymaster parlour.

The Mountfords run a flying herd and have increased cow numbers to 200.

“We buy from trusted sources at Beeston or Shrewsbury markets or from genuine herd dispersals,’’ says Stuart.

A new development this year has been the use of sexed semen – 50 heifers have been inseminated and will calve this year.

The herd, which calves all year around, also produces Belgian Blue cross calves which are sold at Shrewsbury market.

The herd currently yields an average of 8,500 litres of milk at 4% butterfat and 3.25% protein with concentrates fed to a maximum of 8kg in the parlour.

The family aims to gradually grow cow numbers to 300 and has retained their original 7,000 litre milk tank to cope with additional volume.

The milk price was falling when they committed to their new system but took a long-term view on its benefits to the business.

Ross Collison, of Shropshire-based XChanger, whose father, a dairy farmer, established the business, says milk cooling has become a major issue in the dairy sector.

“The milk price has been volatile so farmers have just added to equipment rather than replacing it so systems are now creaking at the joints.’’