The power of pee: a review of the emerging technologies for exploiting urine for electricity and resource recycling.

In this study we describe the range of emerging technologies for gaining useable power from human urine via its use in stationary fuel cells. Generating marketable energy via this means poses huge and clear potential for sustainable development in several ways. Urine is exceptionally local, intrinsically linked to population size and very much a waste product. Redirecting urine away from conventional sewage treatment alleviates the significant effort and environmental burdens of treatment and nitrate removal, or provides a combined solution where none exists. The effective recovery of nutrients avoids the overburdening of natural water courses. The range of technologies emerging around this sustainable resource also have sustainability as their main objective, meaning the use of renewable energy for hydrogen extraction, the use of commonly available materials and catalysts, and an awareness that they must be cheap as well as effective if they are to be accepted. Disadvantages are the research and development activities still needed to make the combined processes commercially viable, and perhaps the gaining of social acceptance to use urine as a resource. The assessment of technologies considers the development towards more simplified processes, their state of development and key enabling materials.