New power cell taps into "blue-green" power source

Researchers from Concordia University in Montreal are looking to tap into what may be the most plentiful yet overlooked source of power in the world. The group has invented a power cell that harnesses the electricity created during the natural processes of photosynthesis and respiration in blue-green algae.

The microorganisms, also known as cyanobacteria, can be found in just about any ecosystem on the planet, across all latitudes, with respiration and photosynthesis taking place in the organism's cells both involving electron transfer chains.

"By taking advantage of a process that is constantly occurring all over the world, we've created a new and scalable technology that could lead to cheaper ways of generating carbon-free energy," says Concordia engineering professor Muthukumaran Packirisamy.

We've seen algae put to similar use in a building in Germany, and on a smaller scale in algae-powered lamps, but algae is probably better know for its potential to produce energy as a biodiesel feedstock.

The Concordia group's prototype photosynthetic power cell is currently small scale, with the algae being placed in an anode chamber, alongside the cathode and proton exchange membrane that make up the unit. An external load connected to the device extracts the electrons released by the algae to the electrode surface.

According to the paper, the team was able to measure open-circuit voltage as high as 993 millivolts, while a peak power of 175 microwatts was obtained under an external load of 850 ohms. The team claims its Micro Photosynthetic Power Cell (μPSC) could produce a power density of 36.23 microwatts/cm², a voltage density of 80 millivolts/cm², and a current density of 93.38 microamps/cm² under test conditions.

Packirisamy says the device is still a ways from being scaled up enough to work on a commercial scale, but he hopes photosynthetic power cells could soon be used to power mobile devices and computers and perhaps eventually become a major source of energy worldwide.

The team's paper appears in the journal Technology.

Sources: Concordia University