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Posted: Nov 02, 2012
University of British Columbia files patent on battery type solar/light conversion cell
(Nanowerk News) The University of British Columbia (UBC) announces the international patent filing for a Battery type Solar/Light conversion cell. This unique generator and storage approach allows both solar power generation and storage within a single cell. Based on photosynthesis, it can be implemented using abundant and readily replenished and renewable biomaterials.
This invention aims to allow industry to install solar photovoltaic (PV) systems with a built in energy storage component. This type of system addresses the natural intermittency of Solar (PV) systems due to the movement of clouds over modules and the need for night time power, and it provides a built-in solution for reducing the total demand on the electrical grid. This unit is anticipated to provide a simple effective method for energy arbitrage by storing direct and indirect Solar/Light energy for later use should the peak energy demands fall several hours after the peak solar generation is available, such as at night. The commercialization of this technical achievement would allow for a much larger penetration of solar PV into the total energy supply and management system and therefore the invention has the potential to increase the value and market for both grid-connected and off-grid solar PV systems worldwide.
The invention is the result of an interdisciplinary venture led by Professor J. Thomas Beatty, who studies photosynthesis in micro-organisms, and Professor John D. Madden in Electrical & Computer Engineering. "We began by asking whether we can learn from nature and make use of natural materials to create useful solar energy harvesting approaches. What we found is an approach that integrates two key components of energy supply: generation and storage".
The new approach involves the use of a light absorbing battery-like cell complete with two electrodes and an electrolyte. Light is absorbed by light harvesting molecules in the electrolyte. Charges are then transferred between the excited light harvesting molecules and mediator molecules, also in the electrolyte, with nearly perfect quantum efficiency. The mediators store the harvested energy, which can then be extracted at the electrodes on demand. Essential to the effectiveness of this technology is the development of highly selective electrodes, each of which primarily reacts with only one type of mediator.
"Unlike photovoltaic technologies, which rely on very thin absorbing layers, and transparent electrodes, this new technology operates with light arriving parallel to the surface of the electrodes, allowing for thicker devices with volume for energy storage," says Madden. "With the new architecture one can envision the creation of solar ponds for harvesting and storage. This is a very general new approach."
The UBC team is supported by Natural Sciences and Engineering Research Council of Canada. Researchers from the University of South Florida and the Australian Centre of Excellence in Electro materials Science are also involved.