We all know that the demand for energy is increasing worldwide, but less well known is that an incredibly valuable energy source is being flushed down toilets and into the sewerage system every day.
When this wastewater arrives at the treatment works, increasingly, it is being processed into energy that can be used to heat homes, provide electricity, and even power cars. Producing and selling this energy can help reduce water utility customers' bills too.
Maximising the green energy generated from wastewater is the focus of an innovative project by UK water company Northumbrian Water and Newcastle University. The collaboration will help optimise the operation of Northumbrian Water’s wastewater treatment processes, converting biogas from wastewater into biomethane, a renewable energy that can be sold and injected back into the gas grid.
“The roll out to other Northumbrian Water sites has the potential to significantly change how we operate our wastewater treatment facilities, and drive significant cost and carbon savings."
This optimisation, as well as being environmentally beneficial, produces savings that can also be passed on to customers, helping to keep Northumbrian Water’s bills low. The company currently has the lowest combined water and wastewater bills in England.
This is one of several green energy initiatives which Northumbrian Water says will help meet its target for net zero carbon emissions by 2027, an ambitious deadline much earlier than the UK water sector’s pledge for 2030, and Government’s target date for all businesses of 2050.
The partners say that on large, complex sewage treatment works, generating energy from wastewater is becoming almost as important as the water treatment itself, but new energy recovery processes require new management techniques. A new process optimisation method was developed during a successful collaboration between Newcastle University's school of engineering and the team at Northumbrian Water.
This research is now being extended, with the employment of Harry Laing, a Knowledge Transfer Partnership associate who will work full time on the project over the next 30 months, funded by UK Research and Innovation (UKRI). Laing will work onsite at Northumbrian Water’s wastewater facility in Howdon to embed newly developed process control systems into day-to-day operations.
By ensuring it runs smoothly and efficiently, and by using new modelling to predict CO2 emissions in the advanced anaerobic digestion (AAD) plant, the project will maximise the value of energy sold back to the grid, and therefore the possible savings to pass back to consumers.
Andrew Moore, Northumbrian Water’s research co-ordinator, said, “Developing robust control and optimisation techniques will aid our energy and carbon management and help us achieve our ambitious net-zero carbon pledge.
“The roll out to other Northumbrian Water sites has the potential to significantly change how we operate our wastewater treatment facilities, and drive significant cost and carbon savings. There is also the opportunity to develop new licensable technology for use by other companies making efficiencies across the water sector globally.”
Northumbrian Water Group is a key strategic partner of Newcastle University. The two organisations work together on innovative research projects including developing a digital replica of Newcastle’s entire water infrastructure to ensure a rapid response to events such as flooding and drought, low-carbon water treatment and student placements.