Millions of litres of expired beer that would have ended up being poured down the drain have been used to feed the thirsty bacteria digesters at South Australia Water’s Glenelg Wastewater Treatment Plant, generating enough energy to power 1,200 homes.
The digesters always do their bit for the environment, and usually provide around 80 percent of the power needed to operate the wastewater plant.
But beer, particularly expired beer, has a high calorific content and methane generating potential, making it perfect food for the digesters to go into overdrive.
By adding 150,000 litres of expired beer per week, SA Water generated a record 355,200 cubic metres of biogas in May and another 320,000 cubic metres in June.
Beer powers 1,200 South Australian homes
The move boosted boosting renewable energy generation at the plant to 654 megawatt hours in a single month.
SA Water Senior Manager Production and Treatment Lisa Hannant explained: “Beer is liquid gold for the digesters and fuelled record energy generation at the plant.”
She said that the Glenelg Wastewater Treatment Plant is always a strong performer in generating its own energy from biogas but the addition of ales and lagers took it to new heights amid the shutdown.
The process is simple and usually relies on sewage waste.
“Glenelg’s co-digestion program 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.”
Put simply, the sludge is heated and then microbes break it down to produce biogas, which can be used as fuel.
Beer to energy: Thirsty digesters ‘do their bit’ for the environemnt
“Harnessing the power of biogas through our on-site gas engines creates renewable energy for the treatment plant and a sustainable alternative for industrial waste that’s otherwise difficult to dispose of and treat.”
Microbes turn beer to energy by digesting it into biogas
“Honourably, our thirsty digesters have been doing their bit for the environment by drinking themselves silly and with such a horrific diet it’s no wonder they produce so much gas!”
Ms Hannant said that many businesses have been impacted by the restrictions in place to stop the spread of COVID-19.
This, she said, is just one example of how the hospitality industry has remained resilient and adapted to ensure their resources aren’t wasted while enabling a positive outcome for the environment.