21 April 2013
By Malcolm Fuller, Contributing Writer
Solar power has been on the radar of scientists and engineers for many years, but has yet to become a mainstream power source for the average household. The main reason? Efficiency.
Solar Energy USA is a company that provides installation of solar panels to residential areas as well as commercial buildings. According to Solar Energy USA, “a small 5 solar panel system that has a total power output of 1,150 watts (1.15kW) costs $7.65 per watt.”
UCLA Professor of Materials Science Yang Yang has been working with organic polymer solar cells for about 10 years in an attempt to make solar power more efficient. Photovoltaic solar cells have shown a lot of potential with their ability to utilize organic polymers to absorb and convert light into electricity.
In addition to being able to produce them in high volumes, organic polymers are a lower-cost alternative to inorganic silicon solar cells, resulting in cheap, lightweight and flexible photovoltaic devices.
Inside the Solar Cells
Drive for Innovation Editor Brian Fuller sits down with Professor Yang to discuss his big breakthrough involving organic polymer solar cells.
“The energy from the sun is a very broad spectrum. It covers all the way from infrared to visible, which we see things, and then to UV. The difficulty of this material is (that it resides on) only a narrow window of the solar spectrum,” Yang explains.
The problem that has faced Yang for the past decade is making that window of the solar spectrum larger, to allow for more light absorption.
Yang said, “our recent breakthrough is, can we actually put two materials, or three materials to cover the whole spectrum… It’s just like a double decker bus. One layer of the bus you can carry a certain number of passengers. You add another layer, you can double the capacity.”
Breaking down his recent breakthrough, Yang explained, “that’s the basic principle of taking two different materials and then layering them, stacking them, two layers, so we can cover broader coverage.”
It’s obviously no coincidence that a lot of solar study is found in sunny regions of Southern California and the Southwest.
Ryan Bouchard, a freshman studying aerospace engineering at the University of Arizona, explains that, “For certain areas in the United States, such as the southwest region, sunlight hours are longer than most in the country and are more direct and intense. For these reasons, solar power would be economical and efficient for states such as Arizona, Texas, and New Mexico.”
According to the Arizona Solar Center, Arizona has the most solar installations per capita number of solar in the continental United States, and for good reason. The state of Arizona receives about 4,000 hours of sunshine each year.
Phoenix, Ariz., generates 2,160-kilowatt hours of energy per year, but only at an efficiency rate of 10 percent.
Bouchard explains that, “to utilize the sun’s power, it is important to develop more efficient solar panels, that can give a larger watt output of energy.”
How long will it take for solar efficiency to increase to a more profitable level? Once it reaches that point solar power will be more economical for the average household to utilize. That could be years, according to most experts, which is why Professor Yang’s work is important; it could just shrink that window.
Here’s Professor Yang Yang explaining his work: