Human waste is an uncomfortable topic for many, but UK water companies are turning it into a valuable resource. Northumbrian Water has become a pioneer in using 'poo power' to generate renewable energy, reducing its annual £40m electricity bill by around 20%.
The process involves anaerobic digestion, where bacteria break down sludge to release methane and carbon dioxide. This biogas is then used to power gas engines or injected directly into the national grid. The firm now saves an estimated £15m a year through its two biogas plants.
Other UK water firms, including Severn Trent and Wessex Water, have followed suit. Wessex Water's GENeco even launched a 'poo bus' in Bristol, running on biomethane from sewage and food waste.
Despite clear financial and environmental benefits, cultural attitudes remain a barrier. Sarah Jewitt, an associate professor at the University of Nottingham, notes that attitudes to human waste are deeply cultural, with 'ick factor' still prevalent.
Globally, the potential is huge. The United Nations calculates that if all human waste were used for biogas, it could supply electricity for 138 million households, worth up to $9.5bn. Pilot projects, such as the Janicki Omni Processor in Senegal, are already turning sewage into drinking water and electricity.
