University of southern California researchers indicate us a more efficient use of graphene photovoltaicsAugust 2nd, 2010
Is it possible to imagine people powering their cellular phone or music/video device while jogging on a sunny day?
A University of Southern California team has produced flexible transparent carbon atom films that may have great potential for a brand new variety of solar cells.
In a paper recently published by the journal ACS Nano, researchers stated that organic photovoltaic (OPV) cells have been proposed as a technique to achieve low priced energy due to their ease of manufacture, light weight, and compatibility with flexible substrates.
The new work shows that graphene, an extremely conductive and highly transparent kind of carbon made up of atoms-thick sheets of carbon atoms, has high possibility to fill this role.
While graphene’s existence has been known for many years, it has only been studied extensively since 2004 because of the impracticality of manufacturing it in high quality and in quantity.
The University of southern California team has produced graphene/polymer sheets ranging in sizes about 150 square centimeters that in turn can be used to create dense arrays of flexible organic photovoltaic (OPV) cells.
These organic photovoltaic (OPV) devices convert solar radiation to electricity, although not as efficiently as silicon cells.
The energy provided by sunlight on a sunny day is about 1,000 watts per meter square, for every 1,000 watts of sunlight that hits a square meter part of the standard silicon solar cell, 14 watts of electricity will be generated, Organic solar cells are less efficient; their conversion rate for that same 1,000 watts of sunlight in the graphene-based solar cell would be only 1.3 watts.
But what graphene organic photovoltaic (OPV) lack in efficiency, can potentially be compensated by its lower price and, greater physical flexibility.
Researchers think it may eventually be possible to cover with inexpensive solar cell layers extensive areas like newspapers, magazines or power generating clothing.
In the meanwhile Prof. Ruoff and his colleagues of the mechanical engineering department at the University of Texas at Austin, are studying the basic science in the development of graphene-based ultracapacitors for usage in electronics and various fields.
Prof. Ruoff says batteries are relatively slow, they can store energy but take time to charge up, and then they distribute energy slowly, over time.
Ultracapacitors can be charged very quickly, within seconds, and discharge in a short time, but, today, they can’t store very much electrical energy.
The development of stable and less costly ultracapacitors is seen as a key step in using wind or solar-generated power, particularly if researchers can find solutions to enable capacitors to store energy longer, that is not yet possible.
Even with their current storage capacity, the graphene devices could provide quick energy when needed in certain situations on the green way.
They could be used, for example, to absorb heat generated in braking an automobile or train, and store it for a short time, and then use it for the electrical needs of the vehicle (i.e. starting the auto or acceleration)
About the writer - Sophia H. Walker writes for the solar battery charger blog, her personal hobby site related to tips to help individuals save electricity using solar powered energy for small accessories.