Realizing the Promise of Renewable Energy

Clockwise from left: Steven McIntosh, Ian Harrison, Paxton Marshall, and Robert Davis
Photo by Tom Cogill

It is abundantly clear that the age of hydrocarbons is coming to an end. Forecasters now estimate that the worldwide production of petroleum will peak by mid-century. And although there is enough coal to keep us warm for hundreds of years, we rely on it at our own peril. The unprecedented consumption of fossil fuels over the last century has already taxed our environment, but these changes pale in comparison to the climate change we now anticipate.

If we are to succeed in averting a dramatic, potentially irreversible shift in climate, we must find alternative sources of energy. U.Va. faculty members have formed the Alternative Renewable Energy Group to assist with this formidable mission. The group is already poised to make a difference in several well-defined and highly promising areas. 

The first is switching our energy supply from complex hydrocarbons like oil to simpler carbohydrates like ethanol. With decades of experience behind them, refiners have developed extremely proficient ways to distill crude oil into its constituent parts and to use catalysis to crack them into lighter molecules that can be used as fuels and as feedstock for industrial chemicals. But as Robert Davis, the chair of the Department of Chemical Engineering, points out, “There is no comparable body of knowledge about refining carbohydrates.” Davis and his colleagues at U.Va. form one of the foremost groups in the world devoted to finding more effective catalysts for biomass processing, setting the stage for integrated biorefineries.

For instance, Davis, who recently received the prestigious Paul H. Emmett Award from the North American Catalysis Society, has devised a recoverable and reusable solid catalyst to convert heavy fats and oils to thinner biodiesel, making biodiesel more attractive economically and environmentally. 

A second area in which members of the Alternative Renewable Energy Group are making a significant contribution is in realizing the promise of fuel cells. Although they were first described 150 years ago, fuel cells have proved to be frustratingly difficult to commercialize, due to problems of cost, reliability, and size. 

Steven McIntosh and Matthew Neurock are chemical engineers working to find new materials for the electrical contacts within fuel cells that provide the optimal balance of catalysis, conductivity, and cost. McIntosh, an assistant professor of chemical engineering, is a leader in developing solid oxide fuel cells. “Because they can use any combustible fuel, including gasoline, diesel, and biofuel, and the existing infrastructure that sustains it, solid oxide fuel cells may find commercial applications in the near future,” McIntosh says.  Neurock, another Emmett Award winner, is part of a team developing better catalytic materials for polymer electrolyte membrane fuel cells. Using his expertise in understanding the atomic features and molecular phenomena that govern catalysis, he has proposed more durable and less expensive replacements for the platinum anodes and cathodes currently used in these devices.

The third area in which U.Va. researchers have the ability to make an important contribution to a sustainable future is in the development of a new generation of high-efficiency, low-cost photovoltaic devices. Paxton Marshall, professor of electrical and computer engineering, points out that the silicon-based fuel cells used today do not respond to the full solar spectrum, generate only a single electron per incident photon, and require large, heavy sheets of silicon, which are in short supply. “Our goal will be to better understand light-matter interactions at the nanoscale in terms of charge generation, transfer, and transport,” Marshall says. “With this information, we can develop nanocrystalline materials, combined with organic matrix and thin film materials, to create photovoltaic cells that are more efficient across a wider bandwidth and easier to manufacture.”      

The University’s ability to mount efforts in all three areas reflects the depth of expertise it has assembled in such fields as electrical engineering, chemical engineering, materials science, and chemistry. As Ian Harrison, chair of the Department of Chemistry, notes, “We have the ability to conduct very basic research, formulate analytic frameworks to understand these processes, and apply these insights to applications. We also have a new building devoted to nanomaterials and a suite of powerful instruments for high-quality analysis. The foundation is already in place for U.Va. to make significant advances in renewable energy.”