Urine is rich in minerals, and it is believed that in the future this resource can be effectively and economically exploited and extracted for the production of electrical energy. At the Bristol Robotics Laboratory in the UK, urine is being studied as a potential energy resource for residential use in the near future (e.g. smartphone charging, etc.). Charging a smartphone using urine requires a battery similar to fuel cells. Professor Ioannis Lerapoulos (pronounced “yan-is li-rau-po-lis”) has developed a system capable of meeting this requirement. The app itself is called “microbial fuel cell” technology, a system that uses living bacteria to generate electricity. Urine contains carbon, phosphorus, potassium, sulfur, magnesium, and creatinine, all elements that microbes need to survive and grow, which is why this technology works the way it does. The center tube of a microbial fuel cell is made of porous ceramic, which allows urine to penetrate the tube and allow microbes to colonize it. As the urine elements are consumed, the electrons generated by the microbes are captured by the cells of the opposite wire coils, creating a battery. However, not just any microbe will do, as certain microbes are required for this process to be effective. To get the right microbes, scientists use the many microbes available in the natural environment (eg lake, pond, river sediments, etc.). Each fuel cell produces 1.5 volts of electrical current, and when connected in series, the output can be increased to a level that will be useful for daily activities. The system can be scaled to be built into future homes, allowing individuals and families to recycle urine as a means of generating electricity. Leropoulos’ work has been funded by the Bill & Melinda Gates Foundation and the European Commission, among others, and is close to becoming commercially available in 2020. For this system to benefit users, individual urinals will be installed, but with re-routed plumbing to divert urine from mixing with waste water into a collection container, providing an on-demand resource that can be used when needed
