02/22/2009 05:12 am ET Updated May 25, 2011

Our Energy Portfolio: a Stanford University Panel Discussion on Fueling the Future

Within hours of Pres. Obama's inauguration, a panel of experts sat down in front of a few hundred students, faculty and alumni at Stanford to discuss issues of a new energy future. The lecture, entitled "Fueling the Future," was part of the A.J. Horn Lecture series on U.S. Energy Production and Consumption.

The moderator, David G. Howell, is a consulting professor in the School of Earth Sciences. Howell seized on Obama's call to "dust ourselves off and begin again the work of remaking America," by asking a series of questions that allowed the panel to go over the details of several energy sources that could help break U.S. dependency on fossil fuels.

Eighty-five percent of the energy we consume in the U.S. is from fossil fuels (i.e. coal, oil and natural gas), more than 60 percent of which comes from overseas. Roland N. Horne, a professor in energy resources engineering, said, "Oil is like toilet paper. We all use it but we don't like to think about it." Horne said, "It doesn't matter how 'clean' it is. We will run out." About transitioning to renewable energy, "there is no choice."

When an audience member asked what the Obama administration could do to help bolster the development of the energy industry, Prof. Mark Jacobson named two things: building an infrastructure of transmission lines, and facilitating the development of more battery-powered vehicles.

But many may be wondering where we should be focusing our attention. So without delving too deeply into the language of technical academia, here is a brief run-down of our energy portfolio, according to this gathering of scientists.

Prof. Jacobson maps the world's wind as part of his research. He said that while the world's total demand of energy is 13 terawatts (13 trillion watts), there is more than 70 terawatts of wind energy available. In other words, we could theoretically power the world five times over with wind energy alone.

In the U.S., the three best places to produce this wind energy are the Great Plains, offshore of the East Coast, and along the Southeast and Southern coast. Of course, we can't really power the world with wind alone because of intermittency -- basically, wind doesn't blow all the time. Jacobson said that wind often peaks at night, which would nicely complement another intermittent energy source that peaks during the day: solar energy.

"Solar energy is a resource that's going to be impossible to ignore," said Stacey Bent, professor of chemical engineering. "The earth is bathed in 100,000 terawatts of solar power," she said. But there are two problems: like wind, intermittency of solar energy makes it difficult to produce energy on a cloudy day, and currently the cost is still not competitive with cheaper sources like coal. Here, Bent stipulates that this cost does not take into account the dollar amount one might assign to dumping carbon dioxide into the air, in which case coal would be much expensive.

To make solar more cost efficient, one has to either make the cells cheaper or more efficient. There have been two generations of solar cells produced, and now the third generation, still in a research phase, aims to maximize efficiency while minimizing cost.

California is currently the world's largest producer of geothermal energy. Prof. Horne, director of the Stanford Geothermal Program, said "I like to think of geothermal as the underground energy source...not just because it's under our feet, but also because it's not really understood."

Only five percent of California's energy comes from geothermal sources, and the rise and fall of geothermal popularity has much to do with legislation. Horne said that geothermal development increased sharply during the 1980s, and after a long plateau, started to gain popularity again two years ago due to production tax credits. Right now, the goal is not just to obtain energy from hot temperature sources like volcanoes, but also from lower temperature sources called "enhanced geothermal systems," or EGS. That means splitting rocks open, injecting them with water, and using the circulating systems to bring hot water to the surface.

Ocean and Tidal
The panel called these the "boutique" energy sources that receive relatively little attention. But Margot Gerritsen, assistant professor of energy resources engineering, said that important research is being done on this source in other parts of the world like Scotland, which as part of an island, has very strong tidal resources.

Prof. Gerritsen explained that we could power 10 percent of our electricity from the ocean through either wave energy in big, predictable offshore waves, or tidal energy in the difference between low and high tides. She mentioned that San Francisco debated for years on building tidal turbines underwater near the Golden Gate Bridge, but this method would be even more difficult and less efficient than building wind turbines above ground.

None of the panelists initiated a discussion about nuclear energy until asked. But once prompted, Prof. Jacobson stated a greater number of reservations about going nuclear compared to his promotion of wind energy. For one, nuclear plants create 25 times more carbon emissions than other methods, particularly when processing uranium. It also takes much longer for a nuclear plant to be in full online operation (10 to 20 years) compared to other methods that would take less than five years. Of course, Jacobson mentioned other problems including nuclear waste and its connotation of being synonymous with development of nuclear weapons.

Prof. Gerritsen added that the new Secretary of Energy Steven Chu mentioned during his hearing that he wants to build more nuclear plants.

Although each panelist tried to promote his or her energy source of expertise, there was a general sense of agreement that "it's going to be a family of these different options," as one professor described it.

A recurring question throughout the discussion was why some of these methods weren't already in place -- if wind or solar energy could power the entire earth several times over, why isn't it happening? Prof. Horne framed the response in terms familiar to the 2008 presidential election: "How do you tell Joe, the gas station owner, 'don't do that, go do something else instead'?" Horne added, "You can't replace a $6 trillion [oil] industry with a substitute $6 trillion one quickly."

Perhaps with more informative gatherings like this one, we can begin planning exactly how to dust off the old $6 trillion industry.