A microbial reverse dialysis test cell.

While we’re probably not going to see this technology replacing our current major energy production methods, the advancement is a substantial step in the right direction for yet another renewable energy source, perfect for developing nations and remote locations.

Though the creation and use of energy from salt water and fresh water was once limited to coastal areas, researchers at Penn State University have begun doing something very interesting. They are using a combination of microbial fuel cells (using sewage water and naturally occurring bacteria to produce electricity) and reverse  bacterial degradation of sewage water with energy extracted from a salt water and fresh-water gradient to produce power.  This combination of technologies has created a microbial reverse-electrodialysis cell.

Formerly, the production of energy from the difference of salt water and fresh water wasn’t the easiest thing to do unless it was near an ocean. This new type of fuel cell now changes things, bringing this energy to places where it was once impossible.

“We are taking two technologies, each having limitations, and putting them together,” said Bruce E. Logan, Kappe Professor of Environmental Engineering. “Combined, they overcome the limitations of the individual technologies.”

This cell can be configured to produce electricity or hydrogen, making both without contributing to greenhouse gases. The test model pictured above produced 5.6 watts per square meter in testing.

Green technology is showing there is still great room for advancement. There’s a good comparison to be made between the computer industry and the renewable energy industry. As early computers were expensive, impractical, and not easily accessible to the majority of the population, so once was green energy production. Over time the technology has advanced to the point where it is embedded in the populations day to day life. Green technology itself has continued to make advancements that make it more accessible and easy to use. From the recent advances in Solar batteries to this potential new water-based battery.