Sunday, April 19, 2009
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by Jacob Gordon, Nashville, TN on 04.16.09
With his planes, helicopters, and other fuel-hungry pets, Dean Kamen admits that he takes a lot out of the world. This just means that, in keeping with his immigrant grandfather’s advice, he has to put more back in. In the second part of our conversation, Kamen shares his obsession with the Sterling engine, telling about the one rigged into his electric car, the ones stationed in Bangladeshi villages, and the 80,000-pound Sterling sitting in his living room.
The maverick inventor also lets us in on his vision of the future, which will see many of our problems evaporate, and new ones born.
TreeHugger: If you recall in Back to the Future II, Doc has the DeLorean rigged up with the Mr. Fusion, and he’s throwing banana peels and Miller High Life in there. This seems a lot like how you describe the Sterling Engine. What is a Sterling engine?
Kamen: Very basically, as a physicist, I would tell you that a Sterling engine is a heat engine which extracts energy from heat and turns it into mechanical work like other heat engines—like the Braden cycle or the Rankine cycle or the Otto cycle or the Diesel cycle. But, it does it as an external combustion device. The fuel that heats the gas inside the engine never goes inside the engine itself.
As a consequence, the Sterling thermodynamic cycle allows you to use a much broader range of fuels because they don't have to be compatible with the inside workings of your engine. They don't have to be mixed with air in such a ratio as to get the kind of spark ignition or compression ignition that you have in the kinds of engines in cars and trucks.
It allowed us to build an engine that could use many, many more different kinds of fuels, particularly ones that would be locally available around the world: anything from olive oil to cow dung to methane gas. And even when it did burn available fuels—like diesel, kerosene, or gasoline—it burns them in a continuous combustion, like your kitchen stove as opposed to the explosions, the bang, bang, bang of your diesel, we can burn them much more cleanly with much less environmental impact than when they are burned in other thermodynamic cycles.
TreeHugger: I've seen you present the Sterling engine as a solution for stationary power generation that can be fed with a vast array of available fuels. “Anything that burns” is how you said it.
Kamen: In fact we had two villages in Bangladesh that we ran for 24 weeks in an experiment with our Sterling engine. As you say, it was stationary power in these little villages. And the only fuel that those engines burned during that time was the methane gas evolving off piles of cow dung that were put into pits next to the engine. Had those pits just allowed that methane to evolve as it would anyway, methane gas is 21 times as bad for the environment as carbon dioxide as a greenhouse gas. And then it turns into carbon dioxide anyway.
So we collected that methane, burned it locally to heat up one end of our engine, literally like you burn methane in your camper stove. And we made electricity and eliminated the methane gas.
(Page 2 of 3)TreeHugger: In addition to that, you have rigged up a Think City electric car (this tiny Norwegian EV that was at one time owned by Ford and is now independent again) with a Sterling engine. Is this still something that you are pursuing?
Kamen: In fact I drove that car you just discussed into work today from my house. It's a lot of fun and our theory there is that eventually (nobody knows how long eventually is, especially when it comes to both developing technologies and having the public accept them) but eventually, a lot of vehicles that move people around will be purely electric. This is because there will be easier and more cost effective ways to carry enough energy in the form of batteries or fuel cells or other storage media to move these vehicles around.
Right now, however, the big advantage of an electric vehicle is that the motor doesn't waste any power when you're not moving (in other words it doesn't need to idle when you're at a traffic light or sitting in traffic). Electric motors are smaller and lighter as a source of torque than the gas engine. They don't need transmissions. They don't need clutches.
There are a lot of advantages to them, but the huge disadvantage of a purely electric vehicle is that it has to carry all the energy to move that car around in the form of batteries. And you can carry about a hundred times as much energy in a gallon of gas as you can in that amount of battery.
So electric cars have to have either hundreds and hundreds of pounds of batteries, which costs thousands and thousands of dollars, or they have very limited performance. We said, let's get the best of both worlds until the rest of the technologies to go purely electric make sense.
We said, let's build a small Sterling cycle engine, put it in a small electric car, let the car have only enough battery to meet the peak performance it needs to develop enough torque to give it some real good get up and go. Let it have enough range on those batteries to do most things. But let's let the little Sterling sit there and always be topping off the charge, and keeping your car warm so you don't waste electricity doing some of the auxiliaries like defrosting and heating. And you never have to worry about being stuck somewhere because the Sterling can come up and charge the batteries.
We thought this was a very nice application for the Sterling. Frankly, to us, it was a stepping stone to getting the Sterling into production so that, as I said before, we could supply millions of these things to the developing world. It could be the source of electricity for the water machine we were just discussing, because although the water machine doesn't need membranes and filters and all the other stuff, it unfortunately does need electricity. And many of the places in the world that don't have clean water also don't have access to electricity.
So, we thought, we've got to develop both the water system (the Slingshot) and the Sterling system together so that we could serve both needs.
TreeHugger: Calling All Innovators is a design competition that you've helped spearhead. Tell us a little bit about this.Kamen: There's no end to the imagination of kids around the world; and some kids are 90 years old.
But it's rare that you can get them all focused and organized on solving particular problems, particularly ones that have a real social impact. A lot of inventors are caricatured as wacky people inventing Rube Goldberg machines. So when these people came to me and said, "Hey, we'd like you to help us highlight a program to get more kids—but, again kids of any age—to use advanced technologies to help develop technologies that the world really needs," I thought it was a good idea.
Maybe by using some of the cell phone technologies and other now-available and cost effective and reliable technologies; maybe by putting prizes or incentives or focus out there we can get more smart, creative people to use their energies to produce new ideas and innovations that will really make the world a better, more sustainable place
(Page 3 of 3)TreeHugger: I know you're fond of your helicopters and airplanes. This must take quite a toll on your personal carbon footprint. Is this a priority for you, and are there things you're doing to try and mitigate it?
Kamen: Well, as I tell everybody, I work all day. I work all night. I work all weekend. People want to know why I do that. And I say, "Well, because I have a problem. I don't want to feel guilty all the time." And as a little kid, one of the best pieces of advice I ever got was from my grandfather, who said, "You've got to make sure that, in the end, you give back to the world more than you took out."
He was an immigrant, came to this country without much. But he was always philanthropic to the extent that he could be. He would always remind me that the better you do, the more have you have to give back. And as I grew up, I decided I really do believe his philosophy: that if all of us would agree to give back a little more than we take out, then by definition, everyday the whole world would be a richer place.
But I recognize that four billion out of the six billion people on this planet really do live on less than two bucks a day. Right now they're not in the position to give much back. I, for lots of reasons, including luck, am in a substantially different position. And so, taking his advice to heart, I believe, "OK, I will give back more than I take out. But, I plan to take out a lot."
And I do take out a lot—I never forget that. And I never get jaded by that. So if I'm going to have the opportunities to design or build or fly in helicopters and airplanes, and it allows me to go places and do things most people don't get to do, and it allows me to do a lot of work most people couldn't get into a day without those tools, if I'm going to have access to that stuff, I have to work extra hard to make sure I'm giving back to the world.
Which is why I started First, a program to get kids into science and technology. Which is why I work on our water project. It's why I work on our electric generation systems that I hope will be deployed around the world. Which is why I work mostly, in my day job, on medical products. I try to work on things that I believe the world needs and I try to work on things that I believe will help make the world sustainable.
TreeHugger: So tell me this: what's going to come next?
Kamen: Well, last night it was about quarter to five in the morning when I finally got to bed. I was working on my 80,000 pound, hundred-and-something-year-old, soon-to-be-converted, Sterling engine that's sitting literally in the living room of my house with a bunch of my zealots. I don't get to sleep a lot, but I don't mind that. Life is short, and I don't want to waste any of it.
If you ask, "What do I think are the next big things in terms of large areas of where technology is going to effect the world?" Proteomics, genomics, nanotechnology—there are so many exciting new fields, literally whole fields being created by what we're now able to understand about nature, that I think it's hard to predict what new fields and technologies are going to be part of life even 10 or 20 years from today. But, it will be very, very different than it is now.
Most of the problems people worry about now, they don't need to worry about. They'll go away. What I'm concerned about is what will be the then critical problems, and how are we going to deal with them.