Biosolar breakthrough promises cheap, green electricity

Posted by Kate Taylor

A team from the University of Tennessee, Knoxville, claims to have developed a low-cost method of power generation based on photosynthetic processes.

Professor Barry D Bruce says his process could make 'green' electricity dramatically cheaper and easier.

"This system is a preferred method of sustainable energy because it is clean and it is potentially very efficient," he says.

"As opposed to conventional photovoltaic solar power systems, we are using renewable biological materials rather than toxic chemicals to generate energy. Likewise, our system will require less time, land, water and input of fossil fuels to produce energy than most biofuels."

The scientists based their methd on a key component of photosynthesis known as photosystem-I (PSI), derived from blue-green algae. This was then bioengineered to specifically interact with a semi-conductor so that, when illuminated, the process of photosynthesis produced electricity.

The system self-assembles, and is much easier to create than Barry's previous methods, he says - indeed, it should be replicable in most labs.

"Because the system is so cheap and simple, my hope is that this system will develop with additional improvements to lead to a green, sustainable energy source," says Bruce.

The solar cell  consists of small tubes made of zinc oxide, engineered to attract PSI particles and quickly become coated with them. When illuminated by sunlight, the PSI is excitedto produce an electron which 'jumps' into the zinc oxide semiconductor, producing an electric current.

Bruce says that while a great deal of improvement is still needed, the mechanism is orders of magnitude more efficient than his earlier work.

"This is a real scientific breakthrough that could become a significant part of our renewable energy strategy in the future," says Lee Riedinger, interim vice chancellor for research.