Poo power

Find out how Yorkshire Water are using poo power to generate electricity at wastewater treatment plants.

Father and son walking through the woods

We’ve all heard and used the sayings ‘Where there’s muck there’s brass’ and ‘Muck for luck’. They infer that from something dirty you can gain wealth or a benefit.

Well, Yorkshire Water is taking this idea on board literally by taking this idea on Poo Power to generate electricity at waste water treatment plants.

With the rising costs of gas and electricity, we see Poo Power as a renewable source for locally generated electricity, with the ability to reduce fuel bills, manage our business sustainably and reduce their carbon footprints.

Poo power facts

Poo power uses a biogas rich in methane which is extracted from the treatment of waste water and sewage to drive turbines. The biogas, predominantly comprising of methane, is produced when bacteria feed on human and animal waste. This process is known as anaerobic digestion and it is a great way to produce green energy, as well as getting rid of waste and the microorganisms that lurk in it. One of the simplest ways of describing anaerobic digestion to young people is the ‘farting’ of millions of tiny bugs within the waste, which produces the biogas.

Positively, when the biogas is burnt for generating electricity, far less carbon dioxide is released than when fossil fuels are burnt. However, it is useful to note that using biogas in this way does have its limitations in that it takes the poo of 100,000 people to generate 51kWh of electricity; enough for 3,000 to 5,000 LED/energy saving light bulbs.

Poo Power is not a new thing. Animal and human waste has been used as a source of energy for many years in countries around the world where electricity and gas are scarce. Small biogas plants are common in Southeast Asia and Africa, where animal dung is used as the fuel. In Australia, pig excrements are used to power farms and chicken poo has been used for generating electricity in the UK.

The use of human waste to generate electricity in more developed countries is relatively new. The use of Poo Power at wastewater and sewage treatment plants has already been mentioned, but even the London Science Museum is planning to turn the waste it gets from its 3 million visitors a year into electricity. The processed waste could produce as much as 1,530 kilowatt hours of electricity a year.

Poo can also be used to heat homes. In Norway, householders are now heating their homes and offices by flushing the toilet. The sewage heat pump plant uses fridge technology to tap heat from raw sewage. Machines at the end of a 300-metre-long tunnel in a hillside in central Oslo suck heat from the sewer and transfer it to a network of hot water pipes, feeding thousands of radiators and hot water pipes in the city. It is believed to be the biggest heating system in the world using raw sewage.

At Esholt, we have built some new Poo “cookers” called Thermal Hydrolysis tanks, which generate enough energy to power 7,000 homes a year!