The nanotech pioneer turns to energy.
George Whitesides is a chemist with a knack for translating lab discoveries into things the world finds useful. He has cofounded numerous companies, including the biotech giant Genzyme. In the late 1980s and 1990s, Whitesides, a professor of chemistry at Harvard University, helped make possible today’s nanotechnology boom by demonstrating the possibility of engineering molecules that self-assemble into ordered materials. Now he is turning his attention to finding solutions to today’s energy crisis. Gleaning new insights from fundamental chemistry, he says, will be crucial to meeting energy needs and cutting increases in greenhouse-gas emissions. TR’s nanotechnology and materials science editor, Kevin Bullis, visited Whitesides in his Harvard office to ask how chemistry can help.
Technology Review: Why is chemistry central to energy?
George Whitesides: Wind power is just wind powering a turbine. With nuclear, the actual power generation of course comes from the disintegration of the nucleus, which is a physics event instead of a chemistry event. But essentially, everything else is chemistry. You take fuel and you burn it, and that’s chemistry. When you run a battery, various elements change their oxidation state, and that’s chemistry. Even in the process of making a solar cell, the crucial steps are largely chemistry. From a flame to a battery to a solar cell, the crucial elements are chemical.
TR: What are our options for cutting down on carbon emissions while meeting our vast energy needs?
GW: If the only issue were supply, we could burn a lot of coal and build lots of nuclear plants, and at least in the United States, for the foreseeable future we could have a fair amount of [energy] supply. Because of climate changes, it’s not just a question of producing energy. It’s a question of producing energy in a way that we can live with in the long term.
If you look at the available pieces, from conservation to nuclear, solar, whatever, and you put them all together, we can’t do it. We have to do something differently, and we have to come up with new ideas. This is not just an engineering problem of taking things that we know and applying them better.
TR: How can basic chemistry research help?
GW: There’s a lot of enthusiasm right now for photosynthesis as a method of both fixing carbon and harvesting sunlight in the form of plant matter, whether it’s plant oils that can be converted into biodiesel or biomass that’s somehow converted into butanol or ethanol. Those processes are a long way from being as efficient as they might be. If we could find a way to dramatically improve the efficiency of photosynthesis, that could be interesting. Can we look at the enzymes that are involved–the catalysts–and tinker with them, readjust them so that they become more efficient?
We understand many of the pieces of the overall process of going from sunlight and carbon dioxide and water to carbohydrates, but there’s a lot that we don’t understand. To reëngineer photosynthesis, we first have to understand it.
TR: But relying heavily on biofuels could have unintended effects, such as raising food prices. Unless we understand the overall system, the things we try to do to make things better …
GW: … can make things worse.
Cellulosic ethanol has some good features. But it has all sorts of problems. We don’t know what the energy costs are of doing this. You need some energy to collect the stuff, and to do the processing and to distill the fluids. There’s the question of whether we really can make large quantities of it. It’s seasonal. You can only do it in parts of the country. You have to then think about taking this relatively low-energy thing, biomass, and collecting it to a central processing station. You can’t afford to ship this stuff over large distances, which means the processing plants are small and intrinsically inefficient for large-scale production. And should we think of topsoil in Iowa as a renewable or a nonrenewable resource? We think about the problem of depleting petroleum reservoirs, but what about the problem of depleting Iowa topsoil? We don’t know how this set of energy technologies all fits together. How do we do agricultural energy production, and how do we think about agricultural land overall–for example, the competition of energy with food production, and just the mere fact that the soil can wear out if it’s not managed correctly?
TR: So what is the solution?
GW: We need long-term investment. We need new ideas. We need a cadre of young people to work on it. This is not a Manhattan Project. It’s not something in which we have a single engineering objective and if we can solve that, the mission is accomplished. It’s going to have a large number of components: Understanding photosynthesis. Understanding how to most efficiently make solar cells. Making hydrocarbon-fuel combustion more efficient. Making energy transmission more efficient. Understanding how the pieces work together so that if we do this, we know we’re not actually going to make the situation worse.