Eccentric energy: Poo is powerful – number 2!
18th October 2019
A year on from our most popular blog post of last year, “Poo is powerful”, we’re revisiting the topic of biowaste - and reviewing some of its benefits.
Read more below:
“Sludge” headlines at Reading Festival
This year’s Reading Festival used human waste from onsite toilets to generate enough renewable electricity to power two homes for a day. Tankers transported around three quarters of a million litres of waste to a processing plant that extracts biogas from the sludge that’s a by-product of the sewage-cleansing.
However, the power generators had to overcome the challenge of filtering out the non-biodegradable waste that festival-goers left behind in the loos – including whole tents!
Flushing value away?
The United Nations University estimates that, globally, biogas from human waste could generate enough electricity every year to power 138 million households.
If treated safely and hygienically, such a solution could be worth an estimated $9.5 billion in natural gas equivalent. This makes it a very attractive option for helping many of the world’s poorest people get access to the energy they need.
Dr Chris Metcalfe, one of the report’s co-authors, explains: “We recycle the nutrients in human waste effectively via agriculture in many places, yet the potential energy value of human waste has been given much less attention to date.”
Improving the environmental bottom line
Sewage treatment plants across the UK are already being used to generate energy from biogas – often to improve the facility’s own sustainability.
For example, Severn Trent has invested £15 million in three biomethane plants. These sewage treatment works (at Strongford in Stoke, Spondon in Derby, and Stoke Bardolph in Nottingham.) will use sewage sludge, contaminated energy crops and food waste to generate biomethane.
Each plant’s capable of producing 500 cubic feet of biomethane an hour and will, between them, generate sufficient power to heat 8,000 homes for a year.