Millions of litres of expired beer from local South Australian breweries have been given a second life by being converted into electricity to power a wastewater treatment plant in Australia.

The coronavirus lockdown closed breweries, pubs and restaurants across the region, resulting in tonnes of unsold beer.

This unused supply was used by the water utility SA Water to power the treatment process of its Glenelg wastewater plant in Adelaide, boosting its renewable energy generation to 654MW in a single month.

The process involves discharging the beer into the site’s digester tanks, where it is mixed with sewage sludge, producing biogas.

The firm, which is owned by the South Australian Government and provides services to approximately 1,5 million people, notes the use of the energy ale led to a reduction in wastage and benefitted the environment.

It estimates it generated a record 355,200 cubic metres of biogas in May and another 320,000 cubic metres in June, by adding around 150,000 litres of expired beer per week.

This energy is enough to power 1,200 houses.

Lisa Hannant, Water Senior Manager Production and Treatment at SA Water, said: “Glenelg’s co-digestion programme adds high strength organic waste from industry to sludge from the sewage treatment process, which is heated in the oxygen-free environment of the large sealed concrete digester tanks so it breaks down through natural bacterial metabolic processes and releases biogas.”

The wastewater treatment facility normally generates enough biogas to power around 80% of its energy needs.

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