The plant has been designed and built for Lake District Biogas, which will operate the site for 20 years, taking feedstock from First Milk’s creamery site.
By feeding the bio-methane into the gas grid, the facility will produce over £3m ($4.26m) per annum in cost savings and revenue, while supplying up to 25% of the Aspatria creamery’s energy requirements.
This comprises low-strength wash waters such as process rinses, supplemented by whey permeate (cheese production residue after protein extraction for use in energy supplements). This is pumped to the anaerobic digestion (AD) plant from the creamery.
First European dairy AD plant feeding bio-methane to grid
This is the first on-site AD plant in the dairy industry in Europe to feed bio-methane to the gas grid, generated exclusively by digesting its cheese-making residues.
When the plant is operating at full capacity later this spring, it will treat 1,650m3 per day of process effluent and whey and generate around 5MW of thermal energy.
It will produce 1,000m3 of biogas per hour, of which over 80% will be upgraded for injection into the national grid. At least 60% of the bio-methane will be used in the creamery for steam generation, with the balance being used by local businesses and households in Aspatria.
Revenue benefits include 20-year index-linked, government-backed incentive payments, with about £2m ($2.84m) per annum in support through the government’s RHI scheme and a further £1m ($1.42m) through the sale of gas to the wholesale market and from the Feed in Tariff scheme for the power generated in the combined heat and power (CHP) engine.
The new plant will take over from the outdated aerobic plant. This will save First Milk from having to upgrade the old, inefficient plant, reducing their effluent treatment costs and carbon footprint, while cutting operational costs, which are borne by Lake District Biogas.
Additional benefits from the deployment of on-site digestion in the dairy processing sector include reduced energy and off-site disposal costs.
Completed on time
Gordon Archer, chairman of Lake District Biogas said, “Completion of this £10m ($14.2m) project on time, given the weather conditions in Cumbria this winter, has been a major achievement for the project team and Clearfleau.
“This is the largest AD plant on a dairy processing site in Europe dedicated to handling the residual materials from the cheese-making process and we look forward to working with Clearfleau on future projects.”
Craig Chapman, CEO of Clearfleau, said, “Dairy processors can generate value from their residues with a better return on investment than for other more conventional treatment and disposal options. This project, generating biogas solely from creamery residues, is based on British engineering and is transforming the way in which the dairy industry manages its residues.
“This shows how sustainability can be an integral part of our food supply chain. We are looking at other dairy projects as more companies realize the energy potential of their residues.”
Initially, Clearfleau refurbished the existing aerobic plant to enable First Milk to reduce levels of phosphate in their effluent, which is discharged to the River Ellen. Supported by the Environment Agency, this will ensure an early delivery of new tighter discharge standards, which are required by the Water Framework Directive.