Much hope for an affordable clean-energy solution has been placed on the potential of biofuels like ethanol. Stanford University's Chris Somerville, director of the Carnegie Institution's Department of Plant Biology, shares that optimism—but also says that technologies are improving the prospects of a whole range of alternative energies. He spoke with NEWSWEEK'S Fareed Zakaria last week in Washington, D.C. Excerpts:
Zakaria: Are biofuels going to get us out of the energy trap?
Somerville: It's not a silver bullet. We need a broad basket of solutions. But it certainly can be important—if we could obtain 1 percent solar efficiency on 1 percent of the land in the world, that would be enough to provide all transportation fuels, or about 20 percent of our total energy use.
What would that mean exactly?
It turns out that many plants, such as sugar cane, actually capture more than 1 percent of the solar energy that strikes them. In fact, the theoretical efficiency for plants is above 6 percent, and some plants will do around 3 percent. To give you a sense of how much 1 percent of the world is—it's about 13 billion hectares. So 130 million hectares would be enough at 1 percent efficiency. The Brazilians say they can devote 40 million hectares to sugar cane.
One of the big problems with almost every alternative energy source is that to get to a large-enough scale, it will require huge investments to meet our needs.
The secretary of Energy's goal, as I understand it, is to obtain about 30 percent of our transportation fuels from bio by 2030. That's on the order of 60 billion gallons, and would require a very large number of facilities distributed around the U.S. [But] it certainly can be done.
The rap against corn-based ethanol is that it takes more energy to produce than it generates. Is that true?
That's probably not true. The best analyses that I've seen say that it's energy-positive. But there's an upper limit to what it's going to contribute, and probably that's in the 12 to 15 billion-gallon range.
How do you come out on this issue of the subsidies for corn-based ethanol?
[Subsidies are] absolutely unnecessary. It looks to me from the price of ethanol and the cost of production that it's still profitable, even without a subsidy. Four years ago, ethanol was selling at $1 a gallon. And at that price, it was necessary. Then ethanol hit $3.50 a gallon about two years ago—at which time farmers were paying off their ethanol plants in a single year.
And what about cellulosic fuel, which is drawn from the whole plant, not just the grains?
We can actually make compounds that look a lot more like biodiesel and biopetrol from fermentation of cellulosics, and I think that within 10 years, we'll actually have not only cellulosic fuels but cellulosic fuels that look just like our current diesel and gasoline fuels.
They'll displace them chemically, with very similar properties. But they will actually be net carbon-neutral—and that's very important because one of the challenges in the current biofuels economy is that we have 240 million vehicles in this country. Only about 5 million of them will burn more than 10 percent ethanol, and we don't have a distribution system for vast amounts of ethanol. So ultimately, the biofuel we want is something that looks a lot more like the fuels we are currently using.
What other alternative energies and solutions do you think are important?
Wind is very underexploited. We could get about a third of our global needs with wind. You just have to put up lots of turbines, and they are big. But they are quite cost-effective. There's quite a bit of capacity in geothermal—extracting heat from deep in the earth to generate electricity. That's rather underdeveloped at present. I also think there's some really important opportunities in geological sequestration—that is, taking fossil fuels and separating the hydrogen from the carbon and then pumping the carbon dioxide back into deep saline aquifers, and then using the hydrogen for various types of fuels.
Do you think you can do that with coal to create clean coal?
Yes. We have to. We have to solve the problem of emissions from coal.
Do you see the hydrogen economy as the future?
I'm not sure. I actually think the future is a basket of technologies. Wind certainly has to be in our future. Geothermal can last indefinitely. Biofuels are certainly a part of it. So there's lots of opportunities.
Where does America stand in this?
The European Union has instituted many more regulations and standards requiring clean energy.
Europe is ahead of us in several technologies. Wind really began in Europe, although since General Electric has gotten into it, it's [been] moving to the United States in a good way. Germany made a large government investment in solar. In biofuels, technically we're the leader, and I think this year we'll pull ahead of Brazil in terms of actual production.
Right now the U.S. looks to me as though there's a very robust sort of groundswell of entrepreneurial and technical activity. Clean tech is sweeping Silicon Valley.
You sound pretty optimistic.
I've been deeply involved in the technical aspects of this for some years, and everywhere I look, I see opportunity. It doesn't require any miracles. There's still time for us to achieve improvements or implementation of alternative energies before the problem becomes really a crisis. [But] there is a crisis coming if we don't do something, and the crisis is not widely understood. It's really a political crisis that will be caused by changes in rainfall patterns around the world that cause people to migrate on a massive scale. It's not the drowning polar bears that are the real problem, it's the people who won't be able to feed themselves because of changing rainfall patterns.