Green Design

A Bio-Solar Breakthrough

An international team of researchers has developed a process that improves the efficiency of generating electric power using molecular structures extracted from plants. The system taps into photosynthetic processes to produce efficient and inexpensive energy.

“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,” said Barry D. Bruce, professor of biochemistry and cellular and molecular biology at the University of Tennessee, Knoxville.

Bruce collaborated with researchers from MIT and Ecole Polytechnique Federale in Switzerland. To produce the energy, the scientists harnessed the power of a key component of photosynthesis known as photosystem-I (PSI) from blue-green algae. This complex was then bioengineered to specifically interact with a semiconductor so that, when illuminated, the process of photosynthesis produced electricity. Because of the engineered properties, the system self-assembles and is easy to re-create. The approach is simple enough that it can be replicated in most labs.

This sustainable solar cell consists of small tubes made of zinc oxide that are bioengineered to attract PSI particles and quickly become coated with them. Done correctly, the two materials intimately intermingle on the metal oxide interface, which when illuminated by sunlight, excites PSI to produce an electron which “jumps” into the zinc oxide semiconductor, producing an electric current.

(UT)