Oct 9 2008
A team of physicists, engineers, chemists and biologists at the University of Kansas and partner institutions is devising nanotechnology that could help supplant fossil fuels and curb climate change. Led by Judy Wu, University Distinguished Professor of Physics and Astronomy at KU, the researchers want to develop better, less-costly solar panels and biofuels.
Why the focus on solar? According to Wu, the sun outshines every alternative because of its ability to cleanly fulfill humankind’s mounting need for energy.
"If you fully use wind energy, for instance, you can only cover about 20 percent of our energy need of 14 terawatts per year," said Wu. "And our energy requirement is going to double by the middle of this century and triple by the end. But the wind is not going to increase. And if you look at fossil energy, we’re going to burn out our resources probably within some short time frame of 100 or 200 years. But with solar - if you look at our 14 terawatts per year in need - you only need one hour of sunlight to deliver this much energy. The sun’s energy is the singular solution for our increasing energy needs."
According to the KU researcher, the trouble is that current solar technologies are inefficient and too expensive, leading to slower-than-necessary adoption of photovoltaic technology.
"Out of the total 14 terawatts per year energy use for the world, only 2 percent is solar," Wu said. "This includes photovoltaic and biofuel. If you look at the photovoltaic market, it is increasing at an extremely high rate of 40 to 50 percent per year. But if you grow at this same rate, it will take many, many years for solar to dominate. So we really need breakthrough technology to speed up use of solar energy."
Wu said innovations in solar energy production will create a "third generation" of PV panels.
"The first generation was traditional silicone wafer-based solar cells with efficiency capped at 31 percent, as predicted by theory," Wu said. "So far, the best solar cell probably gets 20-something percent efficiency. And the cost is also high. The second generation tried to take the same performance, but drop the cost dramatically by one or two orders of magnitude. For the third generation, we want to go toward extremely high performance and take advantage of the second generation in terms of low cost. It eventually could play a big role in energy generation."
According to Wu, advancing to the third generation of solar panels will depend upon nanotechnology, science and engineering that deals with the manipulation of individual molecules and other objects smaller than 100 nanometers. (A human hair is roughly 50,000 nanometers thick.)
A primary objective of Wu’s "nanotechnology for renewable energy" team will be boosting the performance of solar energy capture by better understanding photosynthesis in plant life, which is driven by energy from the sun. The group would fabricate self-assembling nanocomposite materials that mimic photosynthesis - an approach that demands expertise in several different scientific fields.
"If you look at photosynthesis, this entire process involves biology, chemistry, physics and engineering," Wu said. "So that is why this interdisciplinary team is very critical to address the entire process of solar energy capture and usage."
In addition to the variety of collaborators at KU, the team includes researchers at Kansas State University, Wichita State University and participants from the University of Notre Dame, Argonne and Oak Ridge national laboratories and the National Renewable Energy Laboratory.
Other research efforts led by Wu involve conversion of plant biomass into biofuel and consideration of global environmental impacts and commercialization possibilities of technologies developed through KU-based investigations into solar energy.
Indeed, if this effort bears fruit, Wu thinks the state of Kansas would have much to gain.
"First, Kansas has very abundant resources for solar energy," she said. "Secondly, Kansas is an agriculture state. One way to absorb solar energy is through plants like corn or switchgrass. This is how you get the biofuel. It would have high impact on the economy of Kansas."