Systems that create energy from human fecal matter are not new. The idea has been around for a while now, yet never efficiently enough to spawn serious use. The mechanism is called a “microbial fuel cell” (or MFC for short) and it basically uses live electrogenic bacteria that create electricity using the organic material from human byproduct. Generally this sort of system demands an initial power source, driving the production cost considerably higher.
Another idea that has been around for a while is the photoelectrochemical cell (or a PEC) which uses sunlight to separate water into pure hydrogen and oxygen. Similar to MFCs, PECs also necessitate an initial power source causing the same disadvantages. The innovation brought by Yat Li’s research group comes from the synthesis of these two mechanisms to create a “hybrid solar-microbial device”.
By combining the two systems, no supplemental power source is necessary and the average hydrogen gas output is greatly improved. The mechanism works essentially the same as either component would by itself. Electrogenic bacteria begin the process by breaking down organic material in one container, which creates an electrical charge simultaneously. This electricity is used to expedite the electrolysis of water, which occurs in another container with the help of solar energy.
(This is an image of the first hybrid solar-microbial system. http://scitechdaily.com/images/Newly-Device-Uses-Sunlight-and-Wastewater-to-Produce-Hydrogen-Gas.jpg)
The utility and relevance of this creation are extremely prevalent. Aside from the obvious benefits of pursuing reliable and sustainable clean energy, this solution also addresses the issue of waste management. Essentially, the mechanism kills two birds with one stone. The creators of the device are eager to take it to the next step commercially. A much larger scale version is in the workings to be tested on a citywide level.
Source:
University of California – Santa Cruz. “New device harnesses sun and sewage to produce hydrogen fuel.” ScienceDaily, 10 Oct. 2013. Web. 11 Oct. 2013.
