Sci-Tech

Superweeds, air caves and the future of energy

Lawrence Berkeley labs chief says global warming may not be a 100 percent given but the potential consequences mean we have to act regardless.

Steve Chu, director of the Lawrence Berkeley National Laboratory, invariably leaves audiences with two impressions: Science is absolutely fascinating, and humanity is dancing on the precipice of oblivion.

Chu, who won the Nobel Prize in physics in 1997 for coming up with a way to trap atoms with laser light, took a leave of absence from his job as a Stanford University professor to head one of the premier research organizations for the federal government (the Berkeley lab is operated by the University of California for the Department of Energy). He's directing the lab to come up with better sources of energy and ways to conserve it.

One of the more promising solutions lies in the genetic code, he says. In coming years, scientists might be able to breed, or even create, plants that convert more of the energy from the sun into usable energy. Solar also shows strong promise. Chu, who will speak at U.C. Berkeley this week during a seminar on climate change, sat down with CNET News.com recently to talk about alternative energy and other topics. If we don't address the energy situation soon, he warns, war, pollution and economic hardship could be the result.

Q: Back in 2004, you left a fairly good position at a university with a lot of money to head up a federal bureaucracy. It's not a career choice a lot of people would make. Give us the backstory on that.
Chu: Well, it was a complicated thing. I think I was getting to a point in my life where I figured I had one-third of my career left. When I was in Stanford, I began to think about the energy problem. I was also increasingly concerned about the University of California and especially Berkeley, and that it was in danger of slipping. My department (physics) when I was there as a graduate student and in post doc was undisputedly the No. 1 department in the world. It's not anymore. It's still up there, but as the private universities get richer, it has become harder. Berkeley for at least a half a century was the standard bearer for excellence in public institutions. And if it slips, I think all the public institutions in the United States would find it harder.

If the temperatures go up by 3 or 5 degrees centigrade in the Midwest, then the agriculture machine in the Midwest is going to be threatened.
Alternative energy is not a completely new direction for the lab, but it seems to be emphasized a lot more than it was before.
Chu: That's right. In the early to mid '70s, a physics professor named Art Rosenfeld during the last oil crisis said, "I'm leaving high-energy physics and going to see what I can to do for the energy problem." He concluded that the lowest-hanging fruit was on the demand (consumption) side. He really personally worked a lot of miracles and was, I would say, a major factor (in curbing energy demand). From the middle '70s to now, electricity use in California has remained relatively constant even though in the rest of the United States it went up by about 50 percent. There is still a factor of two or more to be had without really dramatically altering lifestyle, just by using energy more wisely. Roughly 35 percent of the energy the United States uses is in buildings and houses. Of that, only a quarter is heating. The rest is all just lighting and air conditioning. We can design buildings much more sensibly--so they don't absorb as much heat, so that they use energy more efficiently.

On the conservation side, do we need to develop new technologies or does the technology already exist and we need to popularize it?
Chu: Both. Most of it is sensible stuff. With south-facing windows and west-facing windows you put overhanging eaves so there are shadows. Use white instead of black (on the outside of buildings)--that alone can cut air conditioning costs. We recently helped Shanghai build an office building that saved a factor of two as compared with other recently built buildings.

Do you think government and potential consumers are sincere about curbing their energy use or finding new forms of energy? Or do you fear that a lot of what is going on is a temporary reaction to the spike in oil prices?
Chu: It's a temporary reaction, but there is something else. Increasingly, people are beginning to believe the warning that's been around the last 20 years about climate change. I'll be the first to admit that 20 years ago the evidence was not very compelling. But each year it's getting more and more compelling. It is roughly analogous to the 1950s, when cigarette smoking really was hazardous, and by the '70s and '80s it was becoming so painfully obvious that the industrial interests could no longer prevent labels and campaigns to encourage people to stop smoking. We've been 20 years with this. The first 10 years it wasn't as compelling, but in each year we've learned more, and unfortunately none of it seems to be good news.

Is there still a debate in the scientific community over global warming?
Chu: The fact that the globe has been warming up for the last 150 years is just a measurement, and I'm not sure how you debate a measurement. Let me be as fair as I can to the naysayers. In the last half million to million years, we've gone through cycles of warmth and cold. You can even go further back--for hundreds of millions of years, we have gone through periods where the globe was much warmer than it is today with the carbon dioxide levels much higher. Do I think all life will be wiped out on the Earth? No. I think humans might pay a penalty. Even before poor polar bears die, there is economic upheaval. This is not known for certain--and in fact it's a big if; it's not compelling yet for sure--but suppose the ocean conveyor belt gets disrupted because of the decrease of the salinity in the Atlantic. The conveyor belt depends on upwelling of warm water and the sinking of cold water, and as it gets fresher the density changes. The Gulf Stream could get disrupted.

Well, that would be very bad for Northern Europe. England is the same latitude as Calgary, Canada. They have very different weather. They would have a freeze in London. England, Germany, France, Scandinavian countries will be frozen.

But here is another thing, which would be more likely. Think about our water supplies, especially in California. We supply roughly 20 percent of the agriculture in the United States. Virtually all of it is irrigated. It's not like the Midwest where it rains. Guess what? Most of the water storage is in the soil. So, this is going to be threatened.

If the temperatures go up by 3 or 5 degrees centigrade in the Midwest, then the agriculture machine in the Midwest is going to be threatened.

Now, is it a 99 percent certainty these things are going to happen? Probably not, but is there a 50 percent chance? Given the consequences, you've got to do something about it.

When you look at the alternatives to coal, oil and gas, the one that gets mentioned the most is solar. Do you think it will become one of the primary sources of energy?
Chu: I think in the long run it can be. In the short run, in the next 10 or 20 years, it won't be probably. Somehow we need some short-term solutions to tide us over. Solar means several things. Wind is solar as far as I'm concerned. Ultimately, solar energy makes wind. Wind can be maybe a 5 to 10 percent effect. But we need to figure out better ways of storing the wind energy. The wind doesn't blow all the time. You've got to be able to store it.

The wind doesn't blow all the time. You've got to be able to store it.
Right now there are two ways of storing electricity on a grand scale. One is to pump water up a hill. The other is to pump air into an underground cave or a used-up gas well and compress it; then you extract it and you burn a little natural gas and you get a turbine to spin. That's actually the best way for large scale energy storage. The Netherlands is going big in wind, and that (compressed air) is going to be their short-term storage.

How about converting solar energy into chemical energy?
Chu: From what I now know, it's not going to be as efficient as compressed air, but it is a much more valuable form of energy, especially in the form of a liquid fuel. Liquid means it has a very high density. Gasoline is incredibly dense in terms of the energy per volume or weight.

As we begin to run out of oil, and as the rest of the world clamors for more oil, there is going to be a real supply/demand problem. In the United States, we need to do this for many reasons. There is a huge balance-of-trade issue. There is the fact that we're buying oil from a lot of people who don't like it and some of that money--like it or not--does funnel to people who really don't like us.

I think it (oil) governs our international policy. It's related to the need to have a large number of aircraft carriers and things like that. It's not a deep dark secret.

China is modernizing its army because it has learned from the U.S. that you need military presence just to ensure access to energy. Just to have the presence--not whether you're going to use it or not--sometimes gets you a long way. I gave a talk in Beijing, and I said that to a bunch of finance ministers. They all nodded their heads.

How promising are biofuels?
Chu: We have great agriculture capacity. We have roughly 450 million acres that are either under cultivation or that we pay farmers not to cultivate. Roughly in the last five or eight years, we've spent $20 billion in agricultural subsidies to grow commodity crops: corn, soybeans and things like that. We no longer can sell our cotton in the world market because it's too heavily subsidized.

Realistically, will the agricultural subsidies go away in the next couple of years? No. Over 30-plus states consider themselves agriculture states. So let's pay them to grow energy. But let's make it sensible. See if we can figure out how to grow the most rapidly growing plants. Ideally they will be self-fertilizing; some plants are naturally self-fertilizing.

You mentioned switchgrass in one of your papers. Is that one of the candidates?
Chu: That's a candidate for a good start. Switchgrass doesn't require as much fertilizer. It's not as water intensive. But we can even develop better plants. Agriculture has been a miracle in this last century. The population has tripled or something like that. And the amount of land under cultivation went up by 10 percent or 15 percent.

If you think about it, the plants we eat now are a very distant cousin--and sometimes didn't even really have distant cousins--from what you find in the wild. Most of what we eat in plants are things involved in plant reproduction. If you think of corn, if you think about soybeans, the things we eat are seeds. What we did is, we fundamentally cultivated these plants to become sex fiends, to spend a lot of energy unnecessarily on reproduction.

So, we can do the same with energy. We can turn plants into growing more of something we can then convert into energy. So it's time to start from a blank sheet of paper, the way we did 5,000, 10,000 years ago.

What about genetic modification?
Chu: We have to be careful. These plants that we make for energy are essentially going to be superweeds, if you think about it. They're going to grow very fast. But you can also make them sterile, and you can make them fragile in different ways. One of the things that plants have invented over the last several hundred million years is a molecule, lignin, that actually protects the cellulose from bacteria or fungus. That was nature's way, the plant's way, of allowing plants to thrive better. Fungi and microbes were out there to eat them up.

So by eliminating the link we can...
Chu: Yeah. That's why trees last so long: There is lots of lignin in there and they're harder to break down. It's actually amazing because when plants "invented" this stabilizing molecule, rotting (became) so slow that some of the tree fossilized, and that's how our coal started.

How about synthetic biology, where you take a genetic component of one cell and marry it with another to get a result?
Chu: Yes. It's a complicated thing. It's not as obvious: "Oh! This plant makes this; this thing makes that; and this organism makes this," and you put them together. The first thing that happens is you've got some dead organism. You've got a bunch of interlocking systems that have to work together. A lot of fundamental science has to be done along the way, which is one of the reasons why a lot of our best comprised fundamental scientists are getting excited about this.

There's always this specter that we could unleash the Frankenstein weed.
How far along is synthetic biology? Jim Swartz at Stanford has come up with organisms that can produce hydrogen, and Jay Keasling at Berkeley is working on a microbe that could potentially produce medicines.
Chu: We don't understand really fully a lot of the complex mechanisms that control the metabolism and control life in itself. You can try grafting-in nitrogen fixation, which people are beginning to do, or drought resistance or pest resistance. You would want to do this stuff even if you're not raising energy. Fertilizer comes from methane, which is natural gas. It's also a source of water pollution, because the modern agricultural methods are very heavily fertilizer-intensive and nitrate run-offs are polluting the water. It's a huge problem in California.

Eventually we'd like to actually make artificial stuff, capture sunlight and make chemical fuel. Why? Because, well, there's always this specter that we could unleash the Frankenstein weed.

If it's in a lab, it's easier to contain. Chu: I don't personally think that's the real issue. I think we can make them dependent on us so that if they ever get unleashed they die. We're actually encouraging these plants to do something that, if left in the wild, they would evolve away from that because it's not in their best survival interests. It is not a survival plan to grow much more corn kernels than they really need to reproduce. What we're going to do is, we're going to try to get them to suck in sunlight the way Americans suck in food.

One issue you don't hear as much about is hydrogen. Do a lot of people still believe hydrogen could be an alternate fuel of the future? Or are the production and storage issues much thornier than they first appeared?
Chu: Some reality has checked in. Hydrogen is actually an easier chemical fuel to make. But you never want hydrogen to generate electricity. This is off the table because converting another form of energy (coal or gas) into hydrogen involves an energy conversion, and in the process you lose energy.

If you want to burn hydrogen for transportation, then you have an energy storage problem. You also have a distribution problem because hydrogen is explosive and it makes metals brittle and it's very leaky.

How about nuclear? We've had it for a long time, but is it politically just too much of a lightning rod?
Chu: I hope that coal becomes more of the lightning rod. It should be. If you think about coal, it's really scary because it's our most abundant natural energy resource. And the countries that have the most are the most energy-consuming countries, namely us, China and then Russia in that order. It has sulfur dioxide and nitrous oxide and mercury pollution problems. In China, it's killing their people, its killing their infrastructure. And people die from mining it, so it's not a good energy source. We don't yet have proven technology to turn it into a clean burning fuel and capture the carbon dioxide and sequester it. We need to do a lot of research on that to make it economically feasible to do all that.

Is there much hope there? I've seen a few venture capital firms invest in clean-coal ideas, and a couple of companies, like BP, have sequestration projects going on.
Chu: Boy, it might have to be at least in the interim until we can get photovoltaic cells down by an order of magnitude or until we get the biomass up and running. We are going to have to have to do something in the next 50 years. The world will increasingly turn to coal and possibly nuclear. Even if you can sequester only for a few hundred years, it will buy time.