Researchers at Stanford University have engineered an ultrasharp nanoscale electrode made of gold that can be used to harvest a small electric current from individual algae cells. In experiments so far, the algae cells survive the intrusion, which could mean that larger electric currents could someday be drawn from entire algae colonies.
Algae have been emerging as the biofuel heroes of a sustainable future and the Stanford development could bring it to a new level, by bypassing the carbon footprint of harvesting plants and processing liquid biofuels.
The Stanford research is based on electricity in plants that is produced from photosynthesis, when sunlight energizes the electrons in individual cells. The electrons then pass through a series of proteins until their energy is spent. Using the gold nanoscale probe, the Stanford team managed to intercept electrons before a protein could latch on to them. Because the only byproducts of photosynthesis are protons and oxygen, in effect the process generates power practically without carbon emissions, aside from the energy used to grow algae. The researchers note that this direct method of harvesting energy from photosynthesis is about 20% efficient and could theoretically achieve 100%. In comparison, photovoltaic cells are up to 40% efficient, and conventional biofuels only use up to 6% of the solar energy available to the plants that are burned.
Kinder, Gentler Biofuels
The other significant feature of the Stanford research is the preservation of plant life while the energy is being extracted. Conventional biofuel production involves harvesting plants, and there is an enormous potential for conserving energy if the same plant could be used over and over again. Researchers at Iowa State University are also on to a process that involves harvesting biofuel from living plants.
Algae, Photosynthesis and Sustainability
In H.G. Wells’s The War of the Worlds, primitive microorganisms emerge as the saviors of a planet under siege by high tech invaders. In a modern twist, the marriage of technology and microorganisms could help bring greenhouse gas emissions down to a more sustainable level. Companies like Joule Biotechnologies are also harnessing photosynthetic organisms to create biofuel, and for that matter an algae diet could also help cut greenhouse gas emissions from cows.
Image: Algae by *higetiger on flickr.com.