Rob van den Braak

Biomass uses biological material such as wood, manure or similar agricultural waste, to generate energy through combustion or as the waste biodegrades. As such it can be used to reduce carbon footprints, which is why the installed bioenergy capacity for electricity generation is growing. But by far our most favourite example of how technology is being used to exploit waste organic material, is the urinal developed for a British university working in cooperation with the international charity, Oxfam.The University of the West of England has installed a very special pissoir at its Bristol campus. The urinal is loaded with microbes which feed on urine. Yum. Male staff and students are keenly providing the device with the necessary raw material for energy generation. The urine is used in a stack of microbial fuel cells (MFC) containing hungry bacteria.The MFCs are an electrochemical system that produces electricity by converting chemical energy into electrical energy. Oxfam wanted the technology to provide lighting for toilet cubicles in refugee camps. However given the copious and widespread availability of the raw materials required for these MFCs to work, there is no limit to how this technology might be applied.According to Professor Ioannis Ieropoulos, director of the Bristol BioEnergy Centre. an MFC “taps a portion of that biochemical energy used for microbial growth, and converts [it] directly into electricity – what we are calling urine-tricity or pee power. This technology is about as green as it gets, as we do not need to utilise fossil fuels and we are effectively using a waste product that will be in plentiful supply.”Printers and publishers might be inclined to convert more space to urinals and provide unlimited free drinks for staff. They might even open up their conveniences to male members of the public, to maximise opportunities for raw material collection. The only difficulty with the technology in its present form is that in practical terms it is inherently sexist. The current generation depends on male input to delivery the raw material to the MFCs, so we really need an additional option better suited to the female form. Consequently, we hope to see developers making more of a splash shortly.

Laurel Brunner