Expired beer from Covid-19 shutdown turned into energy for Glenelg wastewater treatment plant in 2020

Expired beer was added to Glenelg wastewater treatment plant's process that removes sludge from sewage, to be used in the digesters. Inset: One of the haulage trucks delivering 20,000 litres of expired beer to the plant.
Images courtesy SA Water

Millions of litres of beer that expired at South Australian breweries amid the coronavirus pandemic has been converted into renewable energy, helping to generate enough to power a wastewater treatment plant.

Glenelg wastewater treatment plant, west of Adelaide, used beer that expired due to reduced sales in restaurants, pubs and clubs when South Australia first introduced coronavirus restrictions in March 2020.

The beer was discharged into the site's "digester" tanks, where it was mixed with sewage sludge, producing biogas. The biogas was used to feed the site's gas engines, creating electricity.

SA Water welcomed accepting around 150,000 litres of beer each week  – equivalent of powering around 1,200 houses. The beer had such a high energy value that it created greater production of the biogas. It was a win for SA Water because by cutting its costs by generating its own electricity and a win for the beer industry by reducing its disposal and treatment costs.

The wastewater treatment plant, normally generating enough biogas for around 80% of the required energy to run, has become completely self reliant with the beer input.

SA Water was hopeful of sustaining that input once the Covid-19 pandemic was over. The beer that SA Water has received so far came from larger organisations in South Australia but smaller breweries and home brewers also were  encouraged to dispose of their waste.