You are here

Using urine to create electricity

Published: 
Monday, March 17, 2014
Science and Society

Electricity can be generated from a variety of sources. In T&T, it is from natural gas, while diesel fuel is the main energy source used the in power plants throughout the other Caribbean islands. Waste can also be used to produce electricity, both on a large scale for commercial purposes or for small-scale special purposes. On farms, animal waste and organic matter, including food, have been used to produce biogas fuel. Recently, attention has been focused on using urine to produce electricity.

 

The capacity of the human bladder is approximately half a litre, and it is estimated that, on average, a person produces one to two litres of urine daily (one US gallon is 3.785 litres). It would be reasonable to estimate that in schools, universities, shopping malls and entertainment complexes the daily volume production would be quite significant. The same would be true for special events like Carnival. 

 

Urine is a source of electrolytes and potential energy which can be exploited to produce electricity. Electrolytes contain ions, which allow for the conduction of electricity. Think car batteries. The drawback with batteries is that the chemicals that react to produce electricity are stored within the batteries and hence when they are depleted the batteries die. 

 

In fuel cells, however, the chemicals are stored outside and hence can be replenished. This has resulted in fuel cells being used in specialty vehicles and emergency backup power systems. They form the basis for the proposed hydrogen economy. 

 

 

Mail Online and several other sources report of research work at a Research Robotics Lab in Bristol that produces electricity from urine. This is a collaborative venture between the University of West England and the University of Bristol. Urine was fed to microbial fuel cells and enough electricity was generated for the charging of cells phones. 

 

Microbes, the oldest life forms on earth, are micro-organisms, like viruses and bacteria. Microbial fuel cells convert organic matter directly into electricity by utilising the metabolism of live organisms. This research and development effort is in its early stages and looks promising, particularly in those areas of the world that are without electric grids. It is being funded by the Melinda and Bill Gates Foundation, an organisation that works with partner organisations worldwide to tackle critical problems facing mankind.

 

In a Maker Faire event some two years ago, four teenage Nigerian girls demonstrated a urine-fed electrolytic cell that produced hydrogen to power an electric generator. No detailed measurements were given. Last year, it was also reported that during the Rio carnival, portable toilets were outfitted with turbines (micro-turbines, one presumes), which generated electricity as the urine flowed over them. The electricity was stored in batteries. Again no technical details were given. 

 

There are also designs for eco-urinals. Developers at the Zhejian University in China are proposing to use the electricity generated by their eco-urinal to power the infrared sensors and flushing mechanisms. Clearly, the generation of electricity from urine is commanding the attention of researchers worldwide. 

 

The disposal of waste is a global challenge. Innovative and creative solutions are required. It does help to look at older civilisations to see how they dealt with similar uses of environmental and energy sustainability. They tended to view waste as a resource that must be used. 

 

The advantage that modern man possesses is that he has superior technology and this must be used to convert traditional waste products to sources of products and services. This approach is further facilitated by the diffusion of new and emerging technologies to homes and communities.