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Aiming For 'Wild and Crazy' Energy Ideas


This is SCIENCE FRIDAY, I'm Ira Flatow. Back in 2007, Congress funded, and the president signed into law, a new kind of research organization, the Advanced Research Projects Agency-Energy, or ARPA-E. You had heard of DARPA? This was ARPA-E. And its mission is to back energy technologies that are too risky for investors but offer a potentially huge payoff if they work.

The agency has gambled on flywheels, compressed air energy storage, lithium air batteries, even wind energy kits. Cheryl Martin is deputy director of ARPA-E, where they're funding some cutting-edge ideas like new batteries in the hopes of finding the next big thing in energy. She joins us here in New York. Welcome to SCIENCE FRIDAY, Dr. Martin.

CHERYL MARTIN: Thanks, I'm glad to be here, Ira.

FLATOW: It's an exciting time to be involved in energy research?

MARTIN: It is a very exciting time. Energy's finally cool again.


FLATOW: You know, because we are always looking for new inventions in energy and whatever, and we come up with all kinds of new ideas. Let's get into some things that are happening out there, for example the sulfur ion battery. Is that - are you familiar with that?

MARTIN: Yeah, absolutely. I think the bigger picture is that everybody's trying to come up with batteries that have very high energy density. We're trying to go after something that can help us, when you think about fuel in our car engines, right, lots of energy packed into that engine. And so as you think about today's batteries, their issue is that they're not as energy dense.

Just think about it, how much energy you can get into a certain space. And when you look at what's out there, that could be really game-changing. Lithium sulfur comes to mind. It's literally, along with lithium air, the highest energy density you could get.

FLATOW: And how - what is the process that would take that from just the basic research to actually making the lithium air battery?

MARTIN: Yeah, well, lithium air technology's not new. It's been around for a long time. And it's got some great advantages. It's cheap, it's abundant, and it's got this very high energy density. However, when you go to put it into a battery, some of the challenges are often that as it starts to work and cycle, the battery, parts of it dissolve.

And so it literally just loses its life. I think that's...

FLATOW: I hate it when that happens.

MARTIN: I hate that when it - yeah, it's a problem.

FLATOW: So lithium sulfur does have a promise, but it still has...

MARTIN: Challenges.

FLATOW: Challenges.

MARTIN: But there's some really cool breakthroughs out there.

FLATOW: Yes, give us an idea.

MARTIN: We've funded a couple. So if you want to get rid of the whole concept of having it dissolve, make it solid. So the whole idea of could you put a solid - the liquid is called the electrolyte. So could you do a solid electrolyte? So we've funded some effort in that area. There's others out there who've made some progress in those. So that's really tremendously promising.

The idea of, you know, you don't have to have an organic solvent, you could do water, and so it changes some of those dynamics, as well. We've got one funded like that. So I think all of the real change in technology advance and nanotechnology, solid states, have really opened up researchers' eyes. And if you look at a graph of innovation in the lithium sulfur space over the past 10 years, it's a proverbial hockey stick, which is great for innovation. A lot of people are out there inventing.

FLATOW: I remember going out to - years ago, going out to Princeton and watching the tokamak out there, that was a hydrogen - a fusion experiment that was going on. And I said how do you power this thing? And they said, oh, you have to see this. This is a giant flywheel. A flywheel? Flywheels, real big flywheels, they turn, they have a tremendous amount of energy stored in these flywheels.

And I remember actually going out to California in the '70s and seeing cars that had experimental flywheels. And are you working - is that being resurrected the flywheel idea, again?

MARTIN: Yeah, I mean, you know, you're right. Flywheel technology, again, has been around for a long time. Actually, you know, right now in the state of New York there is a 20-megawatt installation of flywheels. There's actually one that I think they're breaking ground on an install today in Pennsylvania of a new flywheel facility.

People are interested in flywheels for exactly the reason you said: They start, stop, their effect really quickly. So if all of a sudden a cloud comes across your solar panel, this flywheel can kick on really fast and balance out the electricity. And so that's a real intriguing advantage to them. It's just taken a while. I do think the utilities are very, very interested, and these demonstrations that we're seeing I think are going to definitely help other people make the decision.

But we're working on the next generation, so...

FLATOW: Tell us.

MARTIN: So the whole question of can you - you know, the real question how much more energy density can these things store, the more the better. And so our belief is that by changing the material, so going to composite materials for these things and being able to get them thin enough, strong enough, resilient enough that you can levitate them and float them to spin them will give us, you know, a five-, eight-times kick.

FLATOW: So there's no ball bearings with a spindle in the middle anymore?

MARTIN: Well, you know, and it's...

FLATOW: It's levitating it magnetically and spinning it?

MARTIN: That's the idea.


MARTIN: And, you know, and I think those types of things, they're already quite robust. But I think you take things to another level if you can get high levels of storage. So yeah, exciting times.

FLATOW: 1-800-989-8255 is our number, we're talking about new energy technologies with Dr. Cheryl Martin. You were in - it's unusual for me to talk to an official from Washington here in New York in our studios. You're here because you had a special visit that you were making.

MARTIN: Absolutely. You know, ARPA-E does award awards to universities, small businesses and large businesses all over the country. And so I was in town yesterday for New York Energy Week, which is actually at both a state- and a city-wide celebration of all that's going on in energy.

And so we were up at CUNY, City University, and celebrating their spinout of a new small company called Urban Electric Power. And their technology is a battery technology that you'd use not for a vehicle but actually in a building that would allow you to manage the peak load of the building. And so it's exciting, exciting to see a technology move from the lab out into the market where real customers are going to start to try it.

FLATOW: I think it's also surprising to see how much solar energy has caught on, people installing solar in their own homes, and it's just terrific.

MARTIN: Yeah, I think the advances in all of these technology areas make things that people wouldn't have thought possible years - you know, just a few years ago seem very, very possible.

FLATOW: Speaking of very possible and very unusual new things, I want to bring in another guest who's created a tiny battery the size of a grain of sand using a 3-D printer. Is that correct? Jennifer Lewis is the Wyss Professor of Biologically Inspired Engineering at Harvard in Cambridge. She's here in our New York studios. Is that right, you made a tiny grain-of-sand battery?

JENNIFER LEWIS: Yes, we did. My group, in collaboration with Shen Dillon and sponsored by the Department of Energy, focused on three-dimensional printing of these types of batteries. And the concept is to integrate form and function to create integrated devices for the first time.

FLATOW: Now it does seem like - and so what would you do with a tiny battery the size of a grain of sand? What uses are...?

LEWIS: So one of the drivers for that is maybe threefold are the things that we're thinking about: autonomous sensor arrays, which are very small sensors that can harvest and then use the battery to store and sense in the environment and then ping a signal back to...

FLATOW: You mean like I could swallow it or something like...?

LEWIS: You could in some cases but I think this is more of an environmental type sensor platform, microrobots and biomedical devices, so coming back to that first example.

FLATOW: And, you know, batteries seem to be the key to everything happening, right? Anything electric, we've got to have the batteries for them.

LEWIS: If you ask a researcher in battery technologies, they will absolutely tell you that, yeah, but it is true. They're so important. And certainly I would say that the - our batteries are 1,000 smaller than the smallest rechargeable lithium ion batteries that you can find commercially. So if you think about that, just like Cheryl was saying, this opens up tremendous space for innovation at these very small land(ph) scales.

FLATOW: Can anyone print one like you did, on a 3-D printer?

LEWIS: Well, not with commercial 3-D printers. We've custom designed and built our own 3-D printers, as well as the inks, the functional inks that allow you to print the anode and cathode in interdigitated fashion. The interesting thing about our batteries is they have feature sizes that are smaller than a single strand of hair, and as you've already mentioned, they fit on the size of a sand of grain.

FLATOW: Wow, wow, what about in general printing batteries? Could we print - if nothing that size, can you go online and get a design for a 3-D battery if you want to print one?

LEWIS: So I think this is going to open up this design space, and although we focused on micro-batteries as the first demonstration just to really push the envelope and show what 3-D printing can do in terms of functional devices, this could be done over large areas, large volumes, and really interesting form factors beyond just planar type devices.

So yes, you know, I eventually imagine that you're going to be able to do that. And then in terms of, you know, really rapidly enhancing the design cycle, this is a great platform for doing that, and...

FLATOW: Yeah because there's a lot of talent out there, right?

MARTIN: Absolutely, and I think the whole idea, once someone demonstrates something is possible, everybody else starts thinking about how they could use it to solve the problem they have. And so I think we're going to see continual innovation. Just asking the guys back at ARPA-E about Jennifer's invention, oh, they were like, oh, well she could use this type of electrode. They had all kinds of ideas to jump in and, you know, innovate...

FLATOW: You crowd-source this stuff, and the ideas come back.

MARTIN: That's part of this, right, is to get people, you know, aware of what's going on, and there's a lot of ideas out there. We don't lack for ideas. We simply, I think, lack for the connection to...

LEWIS: Right.

MARTIN: ...to the problem that they can solve.

FLATOW: How about lacking for the money? I mean how much is ARPA-E funded now compared to how it used to be and where it's going in the future?

MARTIN: So ARPA-E, as you already said, we're a four-year-old agency. We funded $770 million worth of projects, 285 of them so far. Our annual budget this year is about 250 million. And so, you know, for the project size we do, you know, $3 million is a good-sized project to demonstrate what's possible.

FLATOW: But your next year's budget is much lower than that, is it not?

MARTIN: The next year's budget isn't set yet.


MARTIN: So in the budget - we're in the budget process.

FLATOW: Very diplomatic. I can see why you work in Washington.


MARTIN: I've been in Washington for two years.


MARTIN: I'd also like to point out...


MARTIN: ...in terms of the funding, DOE has 46 energy frontier research centers. And the work that I was doing was part of one of those centers. And so that's another way to get innovation out into the popular space.

FLATOW: Speaking of the popular space, let's go to William(ph) in Philomath(ph) - is it Philomath, Oregon, William?

WILLIAM: Yeah. It's Philomath. I was wondering if you could talk about graphing batteries or like carbon nanotubes for electrodes.

LEWIS: Yes. Certainly, there's a lot of work in this area for anodes because the idea is to try to create both cathodes and electrodes to allow - they have this higher energy density, as Cheryl...


LEWIS: ...was talking about. This is really the holy grail of battery space, both energy density and power density.

FLATOW: Graphing is a miraculous sort of carbon...

LEWIS: It is.

FLATOW: ...right?

LEWIS: It is. It's a molecularly thin single layer of carbon in graphitic form.

FLATOW: And incredibly strong.

LEWIS: Exactly.

FLATOW: It's conductive.

LEWIS: That's correct.

FLATOW: You can make things with it.

LEWIS: Yep. That's correct.

FLATOW: Can you 3-D print with it?

LEWIS: Yes. In fact, we have.




LEWIS: So we've made 3-D architectures out of graphene-based inks.

FLATOW: Wow. That's it. That's very interesting. What would you - if I gave her whole budget to you, I'm going to give ARPA-E's budget to you or let me give you $50 million of it...

LEWIS: Right.

FLATOW: ...which - it might be what her whole budget is next year. What would you do with it?

LEWIS: I would say thank you for the best Christmas present ever.


LEWIS: But, no, what we would seriously do with that kind of money is really rapidly advance 3-D printing in this functional integrated electronics and battery space. I think the possibilities of 3-D printing are to go well beyond just printing plastic, which is largely what 3-D printers are doing right now. And we've developed the palliative inks, conductive inks, these battery anode and electrode inks. And I think actually there is unlimitless(ph) possibilities.

FLATOW: This is SCIENCE FRIDAY from NPR. I'm Ira Flatow talking about new energy technologies. Let me ask, well, Doctor, let me ask you the - I'll give you the blank check question. Since I gave your budget away to her...


FLATOW: ...if you had a blank check and you could do anything with it, any size, where would you invest it? How would you invest it? What would you put it into?

MARTIN: Oh, gosh. Well, ARPA-E invests in everything from, you know, new ways of visioning plants so that they could be much more fuel-like and less plant-like to no rare Earth components of magnets and motors, so we could, you know, get out of that problem, to power electronics and could we route the grid, just like we route the Internet.

FLATOW: Let's talk about the grid a little bit. How much does the grid need to be modernized and what...


FLATOW: ...it certainly would need...

MARTIN: Yeah. Well...

FLATOW: ...a lot of work.

MARTIN: ...I mean if you ask pretty much anybody in the electricity industry, right, they would say, you know, if Alexander Graham Bell came in and saw the cellphone, he won't know what to do with it. But if Edison came in and saw the power grid, he would know how to fix it.


MARTIN: And so...

FLATOW: That's very good.

MARTIN: Right. I mean...


MARTIN: ...and so there's a lot of pieces of technology that have not been updated. I mean we've done tremendous amounts to grow the electric grid, but there's a tremendous amount of innovation needed. And it's exciting to see everything from, again, software...

FLATOW: Right.

MARTIN: ...we could route the grid.

FLATOW: Right.

MARTIN: We could not lose so much energy and just moving electrons around.

FLATOW: And if we had more electric cars, they could be part of the grid, could they not help store energy in the electric battery in these cars?

MARTIN: Well, I think the whole idea of storage on the grid is important, right?


MARTIN: It - when you're generating renewable energy and times when you don't need it, you could store it. If you're talking about balancing loads on the grid, you could store it. If you're simply talking about resilience, all those things are helpful. So certainly, electric vehicles having batteries in them, it's the battery component that counts. But absolutely.

FLATOW: Does any of ARPA-E's money going to nuclear power research?

MARTIN: Not today. The way we look at areas is, you know, given our budget size, is 30, $40 million going to make a difference? Is shining a light of that size in the space going to make a difference? We could. We just haven't seen any good ideas that fit that budget constraint.

FLATOW: Dr. Lewis, where do you go now with your tiny little battery?

LEWIS: Well...

FLATOW: I don't mean literally, but where do you move forward?

LEWIS: Sure. I think, you know, one example might be in the hearing aid industry.


LEWIS: So right now, hearing aids, 98 percent of the plastic pieces that you have for molding to your ear or behind your ear are 3-D printed, but none of the electronics are.

FLATOW: Wait. Let me back that up for a second.

LEWIS: Yeah.

FLATOW: Ninety percent are already 3-D printed?

LEWIS: That's correct because you can take a mold of the ear and then just laser print these...


LEWIS: ...very quickly. But then you have to hand pot(ph) all of the electronics in the batteries. Batteries have to be changed every seven days in these kinds of devices. And so we think about an elderly person trying to do that where they don't have the dexterity - wonder if you could have a rechargeable battery just like your cellphone every night, plug it in or put it on an inductively charged charger by your bed stand, it would be tremendous, I think.

FLATOW: And that's where, you know, is there a patent on that? Is anybody setting up companies to do that?

LEWIS: It's funny that you should ask that...


LEWIS: ...because just this week, before we came onto the show, we filed a patent.


MARTIN: Ira, you're an inspiration for the patent.

FLATOW: I've just been doing this too long.


LEWIS: Right.

FLATOW: Yeah. That's - well, that's the kind of thing that drives technologies, having a patent on it...

MARTIN: Exactly, exactly.

FLATOW: ...and getting it into production. But it's always then years before we see something that's going to turn out.

MARTIN: That's correct. That's correct.

FLATOW: Well, I want to thank you for taking time to be with us. I know you have to go. Jennifer Lewis is the Wyss Professor of Biologically Inspired Engineering - I like that - Biologically Inspired Engineering at Harvard University in Cambridge, and your battery project is not funded by ARPA-E, no? We're going to...

LEWIS: We have funding from ARPA-E, though.


FLATOW: You do have funding. We're going to take a break. When we come back, we're going to still talk with Dr. Cheryl Martin, who's the deputy director for ARPA-E. She's here with us in the studios. And then we're going to bring on a couple of twin sisters who are going to come on and talk about their experiments to take soybeans and healthy soybeans to extract hydrogen from water, and it's an interesting story. We hope they'll share it with us. So stay with us. We'll be right back after this break.

I'm Ira Flatow. This is SCIENCE FRIDAY from NPR.


FLATOW: This is SCIENCE FRIDAY. I'm Ira Flatow.

We're talking this hour about next-generation batteries and all kinds of next-generation energy techniques and 3-D printing of batteries, fascinating, future of energy with Dr. Cheryl Martin, deputy director of the Advanced Research Projects Agency/Energy or dash energy, whatever. It's ARPA-E. You know that. I'd like to bring on two other guests now who, in their spare time, have been splitting water to make hydrogen fuel using something you might have in your kitchen cabinet. They are twin sisters. Shilpa and Shweta Iyer, recent graduates of Comsewogue High School in Port Jefferson Station - that's in New York - and winners of the Proton Onsite Scholarship and Innovation Program. Welcome to SCIENCE FRIDAY.

SHILPA IYER: Thank you.

SHWETA IYER: Thank you.

FLATOW: Hi. You know, I watched your video on - up there on the Internet. Quite fascinating.

SHILPA IYER: Thank you.

FLATOW: Let's talk about your winning-project. You found a way of using cheap, abundant soybeans to extract hydrogen from water. Tell us about that a little bit. Choose up who's going to talk.

SHILPA IYER: I'm Shilpa.

FLATOW: Go ahead. Sure.

SHILPA IYER: We wanted something that was going to be cheap and environmentally friendly. And right now, industrially, to produce hydrogen, the use of platinum catalyst, which makes it not an economical option for widespread use, so we decided to go into our backyard and see if we can find something green that would possibly work as a catalyst for hydrogen production.

FLATOW: Mm-hmm. And you found soybeans?

SHILPA IYER: Yep. We went in there with a shoebox, and we tried all the different parts of the plant. We tried the leaves, the fruits, the seeds, and we hit upon peanuts, which showed some promising activity. And we hypothesized that maybe it was because of the protein content in peanuts. So from there, we decided to try soybeans.

FLATOW: Mm-hmm. And so you came up with a way of making the electrodes out of soybeans?

SHILPA IYER: Yep, that's right.

FLATOW: And how much cheaper is that than the way the electrodes are made now?

SHWETA IYER: This is Shweta. And actually, it's much cheaper. Platinum catalysts right now are extremely expensive because per ounce, platinum is around $1,600, whereas our catalyst made of soybeans and molybdenum are much less expensive. Soybeans are nominal and molybdenum is only 40 cents per ounce.

FLATOW: Forty cents an ounce versus platinum, which - wow. And so you made the catalyst and you're able to - and as I say, I saw it on the video, to extract hydrogen out of the water. It's very simply.


FLATOW: And so as we talked about it before, have you got a patent on your project yet?

SHILPA IYER: We do have a patent. We filed a U.S. provisional patent for our catalyst.

FLATOW: Mm-hmm. And have you got a company interested in it yet?

SHWETA IYER: Yes, there is a company, Nagarjuna, who contacted the Brookhaven National Laboratory, and they're interested in our research.

FLATOW: Mm-hmm. How did you get interested in science being twins? You grew up together. Did you both find the interested at the same time?

SHILPA IYER: Yep. Being twins, we're really close and we've been able to share a lot of our interests and passions. And we were always interested in energy research, and we wanted to see if we can contribute something to the efforts of finding something viable for future use. So we decided to try hydrogen because it's the most abundant element, and we wondered why it wasn't being used as fuel.

FLATOW: Mm-hmm. I understand that you spent the summer in India, and then you came back to New York and saw a lack of energy options, especially you were influenced when the New York area was hit by Hurricane Sandy.

SHWETA IYER: That's correct. When we were in India, we actually witnessed daily power outages, and also there are a lot of unreliable energy sources besides that. And coming back to the U.S. is where we taught we have energy at our disposal. We were hit by Hurricane Sandy and realized that the energy crisis is really a worldwide problem.

FLATOW: Wow. And so where do you go from here? Are you going to big energies college? Did someone going to snap you ladies up?


SHWETA IYER: Well, I'm Shweta. I'll be going to Stony Brook University to study chemical engineering.

FLATOW: Aha. You say hello Alan Alda while you're there.



FLATOW: That's where he is, talking about science and electrical engineering. That's terrific. And you're going to be, hopefully, refining what you're doing. Could you make - take it another step further or add to it?

SHWETA IYER: Yes. I like to continue to try to research other methods of hydrogen production and to, perhaps, improve on our current catalyst by using different types of biomass or different types of metal.

FLATOW: Mm-hmm. Well, Shilpa where are you headed?

SHILPA IYER: I'll be going to Cornell University in the fall.

FLATOW: Dress warmly. No, I...



FLATOW: I want to thank you both for taking time to be with us, and the best of luck to you.

SHILPA IYER: Thank you.

SHWETA IYER: Thank you.

FLATOW: You're welcome. Shilpa and Shweta Iyer are recent graduates of Comsewogue High School in Port Jefferson Station - that's in Long Island - and winners of the Proton OnSite Scholarship and Innovation Program. Quite interesting, Dr. Martin, to see youngsters so interested.

MARTIN: Absolutely, Ira. I think, you know, I think the really great thing - they picked out what's the real issue to - how do you find something abundant and cheap? And so I think it's a long way to go until we'll probably have a catalyst from the soybeans out there. But they were going in the right direction, and to think high school kids, you know, it's awesome. It's inspiring, hopefully, to a lot of other kids to say that they can, you know, go out there and invent.

FLATOW: Right. Yeah, you know, we talk about Maker Faires and things like that all the time. And there is no shortage, is there, of ideas? As you said...

MARTIN: Absolutely not. And sometimes it's the untrained eye that brings a new question that everybody with their assumptions about what's possible hasn't asked lately. And maybe this is the perfect catalyst. Maybe it's not, but it's a piece of the questioning we have to do if we're really going to solve this energy problem. So, exciting to hear their story.

FLATOW: Mm-hmm. Here's a tweet from Maggie Ryan Stanford, who says: It seems like everyone you look - everywhere you look these days, young women are kicking major science butt.


FLATOW: And it's the dreamiest. It is. You know, women are getting interested.

MARTIN: Absolutely. Yesterday morning, as part of New York Energy Week, I was Uptown, and we had, I don't know, 150, 200 women in the room to honor four women from government in New York that have made tremendous contribution. And to see that many women across the sector, I mean, as I said, energy's cool, and there are women making a big difference.

FLATOW: Mm-hmm. And being a geek is hot, now, too.

MARTIN: It is. Always has been.

FLATOW: Yes. We geeks know that.


FLATOW: We're trying to become Benjies, which actually is after Benjamin Franklin, because he was a geek, but he was also interested in the arts and music, just like that. So...

MARTIN: Exactly. He was a Renaissance man himself.

FLATOW: Yeah. Benjie. Let's go to Benjie - Bob in Chicago. Hi, Bob. Welcome to SCIENCE FRIDAY.

BOB: Oh, thank you very much. Talk about energy, or abundant, cheap, and young women in energy. What can you tell me about energy storage? I see Danielle Fong, I think it is, from LightSail doing stuff with compressed air for energy storage. Are we doing much work on that?

MARTIN: You certainly - you bring up a good point. There's a lot of ways to think about storage. There's traditional batteries. There's flywheels that we just talked about and compressed air energy storage. So you'll see it, CAES. And there's a number of groups out there, LightSail is one of them, General Compression. Again, the trick is you basically take air, and you can compress it, you know, for example, into an underground cavern. You capture the energy, and then when you release it, you get it back. And the trick is, you know, how do you that without losing the energy? Just like in batteries and flywheels. And so we are continuing to look at all those options.

FLATOW: Mm-hmm. Thanks for calling, Bob.

BOB: You're welcome.

FLATOW: Is the drop in price of photos - of photo panels, solar cell panels, is that a good thing? I mean, it's almost like saying, well, they're very cheap now. Everybody you can use them. But on the other hand, you might say, well, we're not making a profit on selling any of these.

MARTIN: You know, I think any type of technology goes through these periods where something's very expensive. It reaches a tipping point. It becomes much cheaper. So it gets more adoption, as you said earlier, right? It's on a lot of people's roofs right now. It gives us the, you know, the people, the experts in installation and all those things who are out there, there's an industry developing. Well, now the next generations of technology can come along and use those channels to market, to bring more improved and better technology. So I think, ultimately, it's a good thing.

FLATOW: How do you at ARPA-E know when something is a hit, when you have something that's a success?

MARTIN: Well, since we're four, and DARPA's 50, I figure that all we need is the Internet of energy, and we can declare victory and go home. But until then, you know, I think we're going to have to - the path of commercialization in energy's a longer time. But we look at, in the three years that we nominally have projects, what happens at month 37? Are they moving on to spin out a company? Are they moving on to a partnership with a bigger company? Are they in a test bed with the military? The military's a very big user of energy. And so that's how we know if things are moving forward.

FLATOW: You compare yourself with DARPA, which is a good comparison. But DARPA has a huge advantage over you in that they have the D in their name. They're the defense, right? And you would see, these days, that the Pentagon can get anything it wanted if it just ask Congress, because they throw things at it that it doesn't want. And if you just say we're going to make it for the military, you can get funding.

MARTIN: Well, the thing for, you know, yes, DARPA has a D. But the military has a big E called energy that's a very big expense for them. And so, certainly, we spend a lot of time working with the military on their needs. They have needs, you know, far afield. They have isolated bases. They have lots and lots of challenges, right?

FLATOW: Mm-hmm. We've had the secretary of the Navy on here and...

MARTIN: Oh, outstanding.

FLATOW: ...(unintelligible) scientist, and then he seems to be the greenest guy anywhere, trying to save energy to save lives in the military.

MARTIN: Well, absolutely, right? You have a system where you're out in the field. You're isolated from your supply chains, or they could potentially be dangerous. And so you want to make sure that you're using as little energy as possible for everything that you do. You want to make sure, if you had a chance to generate your own electricity, that you can. Subtle things - running a, you know, a generator is not as cheap as running a - as silent as running a solar panel.

FLATOW: Yeah, and it takes men and material to bring that fuel to run that generator, which puts people's lives in jeopardy.

MARTIN: Yeah, exactly. And so that's why they're very, very interested in energy, as well, which is great because the interests are very well aligned with the everyday consumer.

FLATOW: Dr. Martin, we've run out of time. Would love to have you back. Thank you very much for taking to be with us today.

MARTIN: Thank you so much.

FLATOW: Cheryl Martin is deputy director of the Advanced Research Projects Agency-Energy, or ARPA-E, in Washington, D.C. I'm Ira Flatow, and this is SCIENCE FRIDAY, from NPR. Transcript provided by NPR, Copyright NPR.