Going Further with Food: The Rise of Channelling Food Waste for Biogas Production

Almost 50% of the total amount of food thrown away in the UK comes from our homes, representing over seven million tonnes of food and drink wasted from British households annually.

Wasting this food costs the average household £470 a year.  In fact, if we all stop wasting food that could have been eaten, the benefit to the planet would be the equivalent of taking 1 in 4 cars off the road (1).

Food waste is indeed an untapped resource with great potential for generating energy.  Diverting even just a portion of this waste to energy could free up large amounts of landfill space while powering our vehicles and heating our homes, and thus putting a significant dent in our collective carbon footprint.  Perhaps that’s why it is one of the fastest growing segments of the world’s renewable energy sector.

Efforts to channel food waste towards the production of renewable energy in the UK should be lauded as not only will it help mitigate the socio and economic impact of waste, it will also move the country further towards meeting our renewable energy production targets by 2030.

Anaerobic digestion (AD) systems that turn food waste into biogas are well-suited for processing food waste and helping food producers and plant operators become a significant part of the self-sustaining circular economy.  The efficiency of the process in producing energy and managing wastes has resulted in increased enthusiasm in its adoption, particularly by large players in the agriculture and the food and beverage (F & B) sector.

Sainsbury’s supermarket for example, is now using power generated from its own recycled food waste.  This entails the collection of food waste from Sainsbury’s depots, which is then transported to an AD plant where it is used to generate gas.  The gas is then exported to the national gas grid and supplied to Sainsbury’s stores nationwide for power and heating.

This arrangement has made it possible for Sainsbury’s stores to significantly increase their use of renewable energy while lowering utility bills. Beyond that, it has also helped the chain to reduce the amount of its inedible food wastes sent to landfills.

Nestlé UK on the other hand, has built its own anaerobic digestion plant in its factory in Fawdon, where leftovers from making sweets such as Fruit Pastilles and Toffee Crisps are turned into biogas that can produce electricity and heat.  With the AD plant in place, the site tackles around 1,200 tonnes of food waste a year while generating 8 per cent of the factory’s power.

For industry players to fully optimise their AD processes and produce enough biogas that could be turned into energy, it is important that their plant is equipped with the right tools.  For example, a fixed gas analyser can provide helpful analysis of the quality and consistency of biogas produced before feeding into a generator.

This improves digester operation and maximises methane production. Beyond that, the equipment will also assist with process control, which can help protect CHP engines from hydrogen sulphide (H2S) and moisture damage.  As a result, biomethane can be produced efficiently; boosting renewable energy production and meeting both short term operational targets and long term business goals.

Beyond that, additional energy produced can be sold to the grid, adding to the plant’s and manufacturer’s revenue stream.  Biogas plants for example, can make £15,000* worth of energy in a day.  Therefore, keeping CHP engines running and the process optimised onsite are critical in ensuring self-sufficiency and profitability.

At Geotech, we have had extensive experience in supporting plant operators in the F & B and agriculture sector optimise their biogas production with our range of fixed and portable gas analysers such as the BIOGAS 5000, BIOGAS 3000 and the GA5000, all of which have adhered to the highest industry certification standards that include ATEX and IECEx Zone 2.

We aim to expand our long established capabilities in this area as more industry players in both sectors begin to realise the value of turning food waste to energy in the coming years.  This will be done not just in the UK but in more nascent renewable energy markets across the world.

We are barely scratching the surface of the potential of turning food waste to energy.  Reports indicate that some 70 per cent of food waste around the world is still going into landfills and one-third of food produced for human consumption worldwide is annually lost or wasted along the chain (2).

As we look at a rapid increase in energy demands corresponding with the speedy depletion of fossil fuels over the next few decades, transforming our food waste to energy is the right move in addressing this problem.

*based on a 500kW engine

(1) House of Lords : Counting the Cost of Food Waste : EU Food Waste Prevention

(2) Food and Agriculture Organisation (FAO)