A new street lamp uses an anaerobic digester powered by dog excrement to light a residential area in the UK.
Brian Harper, a resident of the Malvern Hills, in Worcestershire, has developed a way to power the area’s street lamps using canine excrement. The system uses an anaerobic digester attached to the street lamps and is the UK’s first dog-poo powered street lamp. To power the lamp, dog walkers collect the faeces in a bag as usual, then deposit the bag in the anaerobic digester attached to the lamppost and turn the handle. The excrement is heated and mixed before being broken down by microorganisms, giving off biomethane to power the light, and producing fertiliser.
Harper is a member of community environmental group Transition Malvern Hills. He spent three years developing the system, helped by a grant from the Malvern Hills Area of Outstanding Natural Beauty organization and Methanogen Ltd, who provided the digester. Around 10 bags of poo are enough to power the light for two hours each evening. Harper’s hope is that the lights inspire people to see that even dog poo has value, as well as encourage people to pick up their dog waste. The next step is to try and have the lamps installed in urban parks around the country.
Small-scale anaerobic digesters similar to that used in this new street lamp are common in many developing countries, such as India, and larger plants in the West, which produce heat and electricity from sewage and animal manure. Recent examples include a biogas digester designed for the home and supermarket delivery trucks powered by food waste. However, a lot of the energy in excrement still goes to waste, largely because it is easier to use cheap fossil fuels. The dog poo street lamp may now light the way to a movement to find sustainable ways of harnessing the power of excrement. Will our streets be lit with dog poo in the future?