Dairy Crest drive towards sustainable energy reflects wider industry move
Dalkia's marketing and communications manager, Nick Burchett told FoodManufacture.co.uk that, increasingly, bigger UK food and drink processors – key Dalkia clients include Heinz and Diageo – were investing in efficient and sustainable energy supplies, as the recession highlighted the wisdom of cost savings.
“A number of companies are investing in biogas and biomass facilities, where the latter generate energy from by-products of production. For instance, dried cake biomass [which involves burning food leftovers – everything from meat to olive oil residue] can drive steam or electric boilers on site.”
“Our business is expanding, and within the food industry there’s a desire to green one’s carbon footprint, and then demonstrate this on food labelling.”
Whereas other companies produce bio-energy as third party suppliers, selling it on to the National Grid, Dalkia specialises in outsourcing solutions for industry – designing, building and maintaining onsite facilities for firms that lack specific engineering expertise.
Due to open in April 2011, Dairy Crest's CHP facility will burn processed wood pellets (sourced by Dalkia from packaging and waste wood), and provide the creamery with all its steam needs for boilers involved in processes such as pasteurisation and whey-drying, while reducing the site’s overall carbon emissions by 84%.
Anaerobic digestion
Another promising means of generating sustainable energy is anaerobic digestion, whereby plants produce a biogas from food waste with a high methane content of around 50-70%. As an otherwise environmentally damaging gas, methane provides a fuel source to drive CHP units and generate heat and electricity.
Burchett said: “There’s a keen interest in anaerobic digestion now across the UK and Europe, whereas it was seen as a novelty even three years ago, and not really taken seriously.
“Nonetheless, anaerobic payback depends on the size of the scheme and the type of material digested, the richness of its methane output.
“A short-term payback might be five years. Certain foodstuffs such as baked beans and potato peelings provide particularly good energy returns, while output from, say, barley processing and drinks processes is not quite so efficient.”
Burchett rates anaerobic digestion and biomass technologies as the most promising for the food and beverage industry, given issues with other green energy-generation technologies.
“Photovoltaics have a long payback, typically over 40-50 years, while wind turbines offer an associated problem – coupled with possible problems with consistency of supply that could blight a food producer – i.e. when there’s no wind!"
Closed-loop arrangements
Another firm pioneering the use of sustainable energy solutions for the UK food industry is South Yorkshire-based Prosper De Mulder (PDM Group), which recently agreed a novel deal with Tesco to provide a closed-loop biomass-to-energy supply from its Widnes CHP facility to the retailer’s neighbouring distribution depot, bypassing the National Grid.
PDM also has an ambitious anaerobic digestion plant building plan, which saw the firm broke ground on its first £12m site in Doncaster during mid-September, with additional technological expertise provided by German stakeholder Saria Bio-Industries.
PDM said the Doncaster plant would utilise waste from across the supply chain – restaurants, retailers and processers, and process 1,000t per week, while producing 2MW of energy annually.
All energy will be sold to the National Grid, and PDM plans to build similar sites in Exeter, Nuneaton, Widnes and Silvertown in London.
Commercial director Phillip Simpson said the future for anaerobic digestion was “extremely promising, given corporate social responsibility objectives in the food industry and a movement away from sending goods to landfill.”
Shortage of waste is not a problem either, he insists, given that millions of tonnes of UK food waste are dumped each year. Where retailers pay for waste collection from PDM, Simpson insists costs are “very competitive” compared to landfill.
“PDM has a £200m turnover, and anaerobic digestion is a relatively small part of our business, but it is growing. Seven years ago there was little interest; now we partner all the major retailers.”
