On-site electricity generation and steam capture for dairy

Aggreko was asked to find a cost-effective solution to reduce energy bills at a dairy site owned by Great Britain’s largest milk supplier and distributor.

The dairy was previously completely dependent on the national grid for electricity, with separate gas-fired boilers used to produce steam for site processes.

This resulted in an inefficient and expensive system where heat and steam, that could be used for processes such as clarification and pasteurisation, was being lost.  

Aggreko’s specialist team provided an evaluation of the site’s utility costs – how much gas the site was using to fire its boilers, the cost per kilowatt hour, and the overall energy costs. This also included comparing the site’s electricity and gas bills, and identifying the cost differential between the current system and one utilising combined heat and power (CHP) to generate electricity and steam on-site.

We installed a CHP solution that included an Aggreko 1,120kW gas-fired generator and 1MW heat recovery boiler. This new system, complete with a heat recovery unit, would allow Müller to generate its own electricity and capture steam and heat for site processes.

Both installations were based on separate 20ft ISO container footprints, with a new transformer installed and stepped up from low voltage to 11,000V, to feed into the high-voltage ring main unit.

Aggreko’s CHP package allowed the customer to operate a far more efficient plant that produced its own steam and electricity. Generating electricity on-site means the dairy do not need to buy it from the national grid at a comparatively higher price, resulting in pronounced energy cost savings.

Because the CHP system used otherwise wasted steam and heat to power site processes, the customer was also able to reduce the amount of fuel needed to power the site. As a result, carbon dioxide emissions have been markedly reduced, while overall site efficiency has been improved.