North East team reveal "power from poo" research

A team of researchers from Northumbria Water and Newcastle University have revealed how sewage plants have the power to run themselves and produce clean energy.

Speaking at the British Science Festival in Newcastle this week, the experts explained how billions of naturally-occurring microbes in sewage could be harnessed to develop a self-powered treatment process and produce valuable hydrogen gas.

Funded by the Engineering and Physical Sciences Research Council (EPSRC), the team are now preparing to install the next generation of Microbial Electrolysis Cell technology at a sewage works in Sedgefield.

Around 2% of all electricity used in the UK is used to treat wastewater, a cost which is ultimately paid for by the public.

Northumbrian Water is already leading the water industry with its award-winning £70 million ‘power from poo’ advanced anaerobic digestion (AAD) plants at Howdon on Tyneside and at Bran Sands on Teesside.

All the sludge remaining after the wastewater from 2.6 million customers in the North East has been treated and is already producing gas which is being turned into electricity.

This new system, led by Tom Curtis, Professor of Biological Engineering, Keith Scott, Professor of Electrochemical Engineering and Dr Elizabeth Heidrich, all of Newcastle University, takes this to the next level. Using raw, untreated waste water at normal temperatures, the entire process is fuelled using the energy from bugs.

Professor Curtis explains: “We spend a lot of electricity treating sewage and it’s totally unnecessary.

“Waste water contains two to three times more energy than we use to treat it so if we can harness that energy we can not only close the loop on sewage treatment to create a totally self-treating system, we will also have spare energy to use elsewhere.

“What’s really clever about this system is that it works on raw sewage at ambient temperature. Most anaerobic digesters require a high-energy, concentrated food source and heat to work properly which means the water has to be removed first and this is an energy-expensive process.

“What we have developed is a system that feeds on the waste as it arrives at the plant - the whole lot goes in and the microbes do all the hard work.”

Maxine Mayhew, Commercial Director for Northumbrian Water, said: “As the industry leader for generating sustainable power from poo it’s a natural progression for us to look to science to see what more can be achieved in the future.

“Currently we are harvesting the methane released by bacteria as they digest the sludge which is then used in gas engines to create electricity.

“Now, in another innovative move to maximise the energy production, we are working to upgrade and purify the biogas so it can be directly injected into the gas grid.

“As industry pioneers of generating power from wastewater we now look to our work with Newcastle University to take this energy production to another level and develop production of hydrogen - the clean fuel of the future.”