Alex Blumberg: Welcome to How to Save a Planet. I'm Alex Blumberg, and this is the show where we talk about what we need to do to address climate change, and how we make those things happen.

Alex: So we all know climate change is a big, complicated problem. And if there's one thing people hunger for when faced with a big, complicated problem, it's a big, simple solution—a technofix. And there are no shortage of candidates for the climate change technofix, the green silver bullet. I guess it would be just the green bullet. But here on this show, we are technofix skeptics. And that's because we've seen these solutions come and go for years. Like, next-generation nuclear that's been just around the corner but not quite here for decades.

Alex: And we've come to peace with the fact that there will not be one perfect solution, but many many different solutions, which for you listeners is probably a good thing. The podcast would get sort of boring if it was the same thing each week. Welcome back to episode 593 about the giant sunshade.

Alex: But that doesn't mean that technological solutions aren't part of the mix. Indeed, a big part of the transition underway right now in clean energy is due to pretty miraculous technology advances. Advances, for example, that made wind turbines and solar panels much much cheaper and much much more efficient. So this week, we are suspending our skepticism of technofixes. And in fact, we are going all in, we're hunting for the weirdest, wackiest ideas that might just actually have something to contribute to a climate-friendly future.

Alex: And to find those ideas, we asked you, our listeners, what are the most creative, out-there ways to generate electricity that you've ever heard of? The ideas that you kind of secretly want to know, could this actually work?

Alex: We asked, and you delivered.

[Listener: A weird way I heard about making electricity is by the art of simply dancing on top of a dance floor.]

[Listener: My creative idea to make electricity is to install small turbines in storm and sanitary pipes that run under roadways.]

[Listener: An interesting electricity-generating method called waste-to-energy. This, I'm understanding ...]

[Listener: Using gravity. For example, like ...]

[Listener: ... is a battery that ran solely on rhubarb juice.]

[Listener: I suggest potatoes.]

Alex: We got a lot a lot a lot of suggestions. So we did some research, and picked four of our favorites, four new technologies which are interesting ways of generating green power. But we thought, as long as we're looking at these new technologies, what if we just sort of game show-ed it up? Hey, sound engineer Peter Leonard, could I get some music?

[Music in]

Alex: [laughs] Great! Maybe some sound effects?

[Applause sound effect]

Alex: Perfect.

Alex: Welcome to Gimlet Studios in New York City. Welcome to the first-ever episode of Electrify This! I'm your host, Alex Blumberg. And today, we've got four alternative energy contestants going head-to-head. And to judge the final results, I've invited two special guests and brilliant climate journalists to help me out.

[Applause sound effect]

Alex: First of all, welcome. It's very nice to have you on the program.

Brian Kahn: Wonderful to be here.

Amelia Urry: Yeah, thank you.

Alex: Those are the voices ...

Alex: I'm not actually gonna do the announcer voice the whole time. Those are the voices of Brian Kahn, managing editor at the climate and environmental justice site Earther. And Amelia Urry, a writer and historian of climate science at the University of Cambridge.

Alex: So we're inviting you on because you guys both have sort of deep expertise and many years' experience sort of like, looking at all the different kinds of technologies, renewable technologies that have come down the pike. And Amelia, you're the historian here. You've probably seen more of these claims than either Brian or I have.

Amelia Urry: Right. I think anyone who's ever had, like, a journalist email contact has probably gotten 50 of these a day in your email inbox. The one thing you learn both in history and reporting is that it's really hard to revolutionize these industries. They're industries really set up to not be revolutionized. It's really hard for any new technologies to kind of catch up.

Alex: Right. We've got this entrenched fossil-fuel-based infrastructure that has been around for going on a century, and so yes, it's really hard to upend that with a new technology because these new technologies have to compete with what we already have, right? They have to be cost competitive, and they have to be able to operate at the same scale as our existing systems do to power cities and factories and, you know, the entire world. But, you know, hope springs eternal, people are always innovating, people are always inventing. That's one of the good things about us. And so what we want to do here is play the two of you the four ideas that we chose out of the just avalanche of ideas our listeners sent us, and we'd like to ask you both to rank each idea along two criteria, using a scale from one to five.

Brian Kahn: Mm-hmm.

Alex: So first, I would like you to rank them in terms of viability, which is essentially what we were just talking about: can we make them cheap enough and big enough to be competitive with what we already have? And second, would you please rank them in terms of just basic creativity? [laughs]

Amelia Urry: The cool factor.

Alex: Yeah. And, like, which one just like, makes you smile. All right?

Brian Kahn: I do want to smile with my energy choices, so this is—I'm very excited for that one.

Alex: All right. So coming up, our first contestant. Right after the break.

[00:05:59.08]***

Alex: Welcome back to the show. So again, Brian and Amelia, we have four contestants, four ideas for very different forms of renewable energy. Are you ready to hear about them?

Amelia Urry: Let's go.

Brian Kahn: So excited.

Alex: [laughs]

[Listener: Hi, How to Save a Planet. This is Andi Hammill from Nashville, Tennessee. I was wondering if exercise equipment like treadmills, bikes or a stair machine could generate electricity. If so, is it enough for gyms to use? Can we also use it to help power our home?]

Alex: All right. Can we use exercise equipment to power our homes? Basic idea behind this: generating power from people. You know, we have successfully done this on a small scale before, right? If you've ever ridden a bike with one of those little generators that's attached to the wheel that lights the light, you're generating power. People have used bikes to power a blender, for example, or charge a phone. So, you know, why not make the extra leap? Can we use exercise equipment to power our homes? So what do you guys think about that idea?

Brian Kahn: So I think it could certainly work as a general rule of thumb.

Alex: [laughs]

Amelia Urry: Yeah. Well, it feels like an easy win, doesn't it? It's like, "Well, I was gonna do this thing anyway, which just sort of feels silly and fruitless. Like, I'm gonna bike in place for an hour anyway." So it'd be nice if you got something out of that, that wasn't just, like, some sweat. [laughs]

Alex: Right. Make it feel less pointless and futile, riding in place. Okay. So we did find somebody who is actually trying to power a gym using the equipment inside and we called him up.

Adam Boesel: I knew it was possible. I don't really know why, you know? The more I thought about it, the more it sounded like something worth trying. And, you know, when I mentioned it to other people, it was something that made them excited.

Alex: So this is Adam Boesel. He's a former teacher and personal trainer. And he also founded the first green microgym, which is a small gym that uses solar power and electricity-generating equipment to offset its energy needs.

Adam Boesel: I Googled, you know, "make electricity by exercising" or whatever. And a couple things came up. One was this device called Pedal-A-Watt, which is still sold today in almost the exact same configuration, but the Pedal-a-Watt was not a good gym machine—too loud, rickety. So what I did was I took that motor and I put a rollerblade wheel on the motor so that it was quieter. Hooked that up to a spin bike flywheel.

Alex: So this guy is actually doing the thing our listener suggested—using his exercise equipment to generate electricity, building lots of his own machines for his microgym. But after he prototyped these exercise bikes and really put them in motion, he realized there was a problem: gyms require a lot of electricity—lights, AC, big TVs—and humans, we don't actually generate that much power.

Adam Boesel: Yeah. Just to give you an example. In 2020, I decided to see how many watt hours, you know, how much electricity I could make if I exercised every single day. And I literally did every day, except for, like, six days of the whole year, a 30-minute bike ride. I rode my bike every day, and I made about 15 kilowatt hours, something like that?

Alex: Working out 30 minutes a day every single day for a year got him 15 kilowatt hours. You guys are energy reporters. Is that a lot or a little?

Brian Kahn: That's pretty weak. I mean, I shouldn't say that. It was a very good effort that he made, but in terms of energy ratio, not so great.

Amelia Urry: Yeah. Well, how much is the light bulb? Like, a light bulb is 60 watts. So you could keep that on for, like—I can't do that math in my head right now, but ...

Alex: Our crack team of number crunchers is looking it up. It looks like that's enough power to power an incandescent light bulb for about 10 days, or to wash and dry, like, three loads of laundry.

Amelia Urry: Oh no! [laughs]

Alex: So one year on an exercise bike gets you 10 days of one light bulb or three loads of laundry.

Amelia Urry: I was hopeful about—yeah, I was hopeful about the gym idea, because it seems like as your demand increases, you'd also have more energy supply, but it turns out not very much energy supply, huh?

Alex: Right. Doesn't seem that good. So ranking this idea, Amelia, what would your—give me the viability scale, and then give me the creativity scale.

Amelia Urry: Yeah. I feel like you could have tracked my viability rankings like the stock market over the last couple minutes, and you would have just seen it sort of plummet in a very precipitous way. That's a bit sad.

Alex: [laughs] A big selloff.

Amelia Urry: [laughs] Yeah. Yeah, I had really high hopes. Yeah, I guess—I mean, I don't think it's nothing, right? Like, in theory, if you could scale it, maybe it wouldn't be nothing. But right now, it seems like close to nothing. Maybe like a two on viability?

Alex: Right. Yeah.

Amelia Urry: Creativity's still high. That's a four- or five-star idea. It just didn't quite deliver.

Alex: Right. And then Brian, what was your number?

Brian Kahn: I feel bad, but I got to give it a one as far as a long-term solution, but I do think the creativity is a five. I'm on total polar opposites on this scale. But I love it, I love the effort.

Alex: [laughs] Excellent. And for our listeners at home, don't worry about keeping track of these numbers in your head—we're keeping track and we'll give you a tally of the final scores at the end of this episode so don't worry about doing the math in your head. All right, moving on. Are you ready for idea number two?

Brian Kahn: So ready.

Amelia Urry: Oh, yeah. Yeah.

Alex: All right. Let's do it.

[Listener: Hi there. My name is Kelly, and I'm 32 from Ann Arbor, Michigan. One of the most interesting ways of generating electricity that I've heard about is known as "poo power" at the Detroit Zoo. They anaerobically digest herbivore manure and other organic waste to power the zoo's onsite hospital.]

Alex: All right. So once again, we have talked to somebody who is actually active in this technology, but before we hear from them, have you guys heard of poo power?

Brian Kahn: I've heard of poo power and I feel somewhat bullish on poo power. So I'm excited to learn more.

Alex: [laughs] Amelia?

Amelia Urry: You're a poo power partisan. I don't know if I've heard it under that name. I love the name. I think it's got legs as far as branding goes. I haven't heard a lot about it.

Alex: All right. Well, let's hear a little bit more about it. We reached out to a guy named Matt Lapshan. He is the landscape manager for the Detroit Zoological Society. And the first thing he told us: they only use certain poop from certain animals.

Matt Lapshan: The idea is—and this is all, we're talking all about herbivore manure. So this is not, you know, large cats. This is not chimps, gorillas. This is, you know, zebras, rhinos, plant-eating animals.

Alex: Second thing Matt stresses? It's not just poop.

Matt Lapshan: It's a pile of manure, but it's mixed with bedding. It's mixed with straw and hay. Probably more than actual, like, rhino, you know, manure or zebra. You know, from a volume standpoint, it's a fair amount of straw and bedding and things that are mixed with it.

Alex: Third thing? Sure it smells, but maybe not as bad as you would think?

Matt Lapshan: I mean, you know, it doesn't smell like potpourri, but it's not the worst thing ever, either.

Alex: All right. So the way it works, every week, Matt loads this sort of smelly mix of herbivore poop and straw into something called a bio-digester.

Matt Lapshan: We'll go out there, go through our maintenance protocols and then heat it, spray liquid manure or leachate on it, and that's when the process of gas creation starts.

Alex: The gas creation. That is the key part here. That is the "power" in poop power. As this non-potpourri decomposes in the bio-digester, it releases methane gas, which is then captured and used to power a generator, which creates electricity for the zoo's animal hospital. At peak performance, that would be about 470,000 kilowatt hours a year—enough to power around 44 houses. So way better than a treadmill, although this bio-digester is still not quite that productive. Matt says they are working on it, though. All right. Amelia and Brian, what do you guys think? Brian, you wanna go first?

Brian Kahn: Yeah, it sounds like a better use than just letting the poop sit around. So if the poop is gonna be there, you may as well get something out of it.

Alex: And give us your ranking. Viability? What do you think?

Brian Kahn: So viability? I mean, it sounds like it's doing a great job. I mean, it certainly is doing a lot better than the guy on the bike, you know, powering his light bulb for a few minutes. So I'm gonna give this a solid—I'm gonna give it a solid four. You know, what keeps me from going to a five is like, methane is a dangerous greenhouse gas, so, you know, you have to be aware of leakage and things like that. But I think viability-wise, like, it sounds like they're doing a good job, so I'm gonna give it a four.

Alex: If somebody had told you that, like, what is gonna generate more electricity: rhino poop or a guy running for a month on a treadmill? [laughs] I don't think I would've gone with the rhino poop.

Brian Kahn: I would have had a lot of faith in the guy on the treadmill. I mean, and I'm not much of a runner, but I would have had faith in him. But rhino poop? Who knew? Good work, rhinos.

Alex: So viability four. Creativity? What do you think?

Brian Kahn: I mean, I think it's a five. It's a very creative use of—I mean, like I said, if you got the poop, you may as well use it. And it sounds like they've found—I can't imagine what else you would be doing with poop otherwise. So I think it's a very creative process as well.

Alex: All right. Amelia, what do you think?

Amelia Urry: Yeah, I love this idea. It feels like the best kind of version of the "We were doing this thing anyway, and now we get more free stuff out of it." And ...

Alex: Pooping?

Amelia Urry: It's like—yeah, it's that children's book, right? Like, everybody poops. You can't get away from it. So, yeah. I think—I feel like in terms of viability, maybe the biggest challenge is just making this an attractive thing for lots of people. I don't think people are gonna be installing personal, you know, methane harvesters near their houses. But maybe.

Alex: Right. Well, we do have big landfills of organic waste, right? So ...

Amelia Urry: Well also, have any of you ever visited a wastewater treatment plant? Like, the stuff has to go and be smelly somewhere.

Alex: Right. Yeah. And in fact, there are places where this is being used in conjunction with, like, sewage processing. Right here in Brooklyn, there's a sewage treatment plant with bio-digesters attached. It processes more than 300 million gallons of food waste and sewage sludge every day, and it turns it into natural gas that heats houses throughout the city. It's not turning it into electricity like at the zoo, but the overarching poo power principle, if you will, is the same. And then there's other places where this is being put into use: you know, on farms all across the country. There's more than 300 farms with active bio-digesters that are being used to convert farm waste like cow poop into biogas.

Amelia Urry: That'd be pretty good. So yeah, I think in terms of viability, I'll give it a four.

Alex: Mm-hmm.

Amelia Urry: Yeah.

Alex: And what's your creativity score?

Amelia Urry: My creativity score? It's pretty good. Yeah, I'd say also four.

Alex: All right.

Amelia Urry: Yeah.

Alex: Okay. Excellent. All right. So are we ready to move on to the next one?

Amelia Urry: I'm excited and a little scared. What could be next?

Alex: [laughs] What could be next? We're gonna tell you right after this break.

[00:18:00.11]***

Alex: Welcome back. We're playing a special game show edition of How to Save a Planet today called "Electrify This," where we're listening to and ranking four weird, experimental technologies, new ideas about how to generate power. And we've now arrived at the third idea courtesy of this listener.

[Listener: Hello. My name is Brett. I'm 52 years old, and I live in Bend, Oregon. I'm interested in electricity generation from ocean swells. It seems that if ocean swell generation could be tied to offshore wind projects, then the ocean swell generation could simply piggyback onto those wind project platforms and transmission infrastructures to share the costs, improving its economic viability. I'm curious to hear what your experts have to say on this.]

Alex: All right. We are too. But before we get to the expert, just initial reactions. Have you guys heard of ocean wave power?

Brian Kahn: I've heard of wave power. I like this listener's idea of putting it next to wind turbines. Like, let's just, you know, maybe cover them in solar panels, right? Just do it all at once all together. Maximize that energy. But I've heard of it, yes. And I'm intrigued to hear more about it.

Alex: Well, perfect because more you shall hear from this expert.

Belinda Batten: My name's Belinda Batten. I'm a professor of mechanical engineering at Oregon State University.

Alex: Belinda is also the former director of the Marine Energy Center there, and her area of specialty is wave power. And most climate, I don't know, normies, don't know anything about wave power. For those of us who have heard something about generating power from the motion of the ocean, Belinda says, often as not, they're not thinking about wave power, they're thinking about tide power. Which is very different.

Belinda Batten: Tidal energy is getting energy from the way the tides come in and go out. And those tides going back and forth at tremendous speed, and that's where you get the tidal energy.

Alex: And tidal is nice because, like, as we know, time and tide wait for no man. And so the tide is always either coming in or going out. Even more than wind, it's probably a pretty regular source of energy. But Belinda says wave energy is a completely different thing. And it's more complicated, right? So the tide, it's either going in or out—two directions. Waves, they go all over the place. And there's different kinds of energy inside each wave.

Belinda Batten: So if you think about the waves coming up onto the shore and breaking, that's called surge. And then if you're out in the ocean, the waves go up and down. That's called heave. And then the particles in the water also go around in circles, and so that kind of motion is another way you could get energy from the ocean waves.

Alex: The operative word being, I guess, "Could." Because right now, we don't have one right way to get that wave energy and turn it into electricity. There are lots of prototypes out there. Belinda herself has been involved in making a few of them at Oregon State's test facility. Some of them float around on the surface like buoys, some are submerged deep in the water off the Oregon coast, but so far, they're all at the very beginning stages. There's nothing that we can just plug into the grid that makes power from waves.

Belinda Batten: We're probably about 30 years behind wind. If you wind the clock back into the '80s, I was too young to know, but I've had other people tell me that you would pass wind farms in California where you had two-bladed, three-bladed, single-bladed, ones that look like a wind turbine now, ones that spin around the vertical axis, because they were trying to figure out what's best. That's similar to what we're doing here with wave energy.

Alex: And if we could figure out a way to convert wave energy to electricity, there's a lot of potential there. Scientists estimate that the energy produced by waves off the coasts of the United States could be as much as 2.64 trillion kilowatt hours. That is more than half of the country's entire electricity generation for all of 2020. All right. Wanna rank it? Amelia, you go first this time. Viability?

Amelia Urry: Yeah, yeah. So it sounds like there's some—like, we're not close, but it seems to me like it's still a pretty good idea. So maybe it's not, like, viable tomorrow, but I think maybe like a three? Could be quite promising in the near future.

Alex: Got it. And what about creativity?

Amelia Urry: I mean, it's no poo power, but it's like [laughs]—it's pretty cool. And then, like, I feel like I'm giving them all too high a score, but I'd say it's also, I'll give it a four. Yeah.

Alex: Okay. Brian, what do you think?

Brian Kahn: So, you know, it's interesting. I feel like the viability, the comparison to wind turbines of yore in the '80s is very interesting in the sense that then it really was like the—I mean, it was the wild west in a lot of ways of wind turbine design and installation and everything. I've actually written about it. California was basically the wind energy hub of the US at that time, and it was let a thousand flowers bloom kind of idea as far as how they approached it.

Alex: Yeah.

Brian Kahn: So I feel like, you know, knowing that this wave energy is at that stage, knowing where we are now with wind energy, I think it's working towards something that could be cool. But, you know, given what we need right now, like, we need a lot of stuff to get installed for clean energy now. So, you know, viability as like a commercial thing, I'd say, you know, it's probably two, maybe a two and a half if I'm feeling generous, which I think I am. I'm gonna give it a two and a half.

Alex: Two and a half. All right. And creativity?

Brian Kahn: I think it's very creative. I mean, you know, again, it's kind of like poo. The waves are there. They're always there. You know, what else are they doing? I guess surfers are using them. So I should—you know, I don't want to take away the surfers' surf spots, but I think if there are ways to deploy this, you know, that didn't interrupt the natural flow of things, the natural world, surfers' favorite surf breaks, like, you know, I think it's a pretty creative solution. So I'm gonna—I think I'm also feeling a little middle of the road on it. I'm gonna give it a three.

Alex: Three. All right. Great. We have now arrived at our last idea, and it's a doozy. Are you ready? Let's hear it. [laughs]

[Listener: Hey, How to Save a Planet. I'm wondering if electric eels could provide some sort of energy. Like, say you had a big pool of eels, could it power anything? Thanks!]

Brian Kahn: This sounds like a nightmare, to be honest. I mean, I'm sorry. I love this reader's passion, or this listener's passion, where they're coming from, but this sounds like an absolute nightmare to me.

Amelia Urry: My first thought is like, this is what the Bond villain has in their secret lair. Like this is ...

Alex: Well, let's see. Let's not judge too harshly. And to help us learn more, we're gonna hear about someone named Miguel Wattson. And Miguel Wattson is germane to our story, not because he is a scientist or a researcher, but because he is, in fact, an electric eel.

Kimberly Hurt: It was just a funny in-house name that we came up with. I believe it was actually one of our interns who picked it, and then it stuck.

Alex: This is Kimberly Hurt. She's an aquarist at the Tennessee Aquarium, where Miguel Wattson lives. And Wattson—that's with two Ts like "watt," the unit of measure for electricity. Get it? Anyway, Kimberly's main job is to take care of Miguel. And she says he's pretty popular because engineers from the local college actually built a system that detects when he produces a shock, and those engineers linked him to a light system in the aquarium, and also to a Twitter account. So every time Miguel produces a shock, his Twitter account says things like "POW" and "BAM!"

Kimberly Hurt: I think we've been coasting somewhere along, like, 30,000 followers on his Twitter account.

Alex: Actually, he's got more now. He's got, like, 58,000 followers on Twitter. The eel does. How many followers do you guys got?

Amelia Urry: [laughs]

Brian Kahn: I'm not on the level of the eel, apparently. I aspire to be.

Amelia Urry: It's a different order of magnitude.

Brian Kahn: Yeah, I aspire to be Miguel Wattson. That's what I'm gunning for now. We're in a competition.

Amelia Urry: I don't think it's a competition. I think Miguel just earned a few new followers. I think it's 58,001 now.

Alex: Right. So anyway, Kimberly told us that after hooking Miguel up to Twitter, they figured why stop there?

Kimberly Hurt: Some of our other AV guys in house got the idea, well, if he's connected to lights and he's connected to Twitter, why can't we connect him to a Christmas tree too? So then we added the Christmas tree on, so that as he produced electricity, that the lights on the Christmas tree would flicker as well.

Alex: [laughs]

Amelia Urry: This changes everything. This absolutely changes everything. It's no longer a supervillain lair. Like, you can have those Christmas displays that are synced to lights or to music. You know those? It's like now your lair is like the most festive place.

Brian Kahn: We need to get Miguel Wattson, to power, like, the Bellagio display in Vegas or something like that. Really just go all in.

Alex: Every time Miguel turns on his electricity, the fountains shoot up into the air, yeah. I mean, I guess also I should clarify something here: Kimberly said that he's not actually powering the tree, it's more like he's operating the light switch. So electric eels, they're not just producing electricity all the time. It turns out they mostly use it for two reasons: as a way of navigating, they produce these low-voltage shocks that travel through the water and tell them where they are. And then they also produce these high-voltage shocks for hunting or when they feel like they're under threat. And those high-voltage shocks are super powerful—eels can generate up to 600 to 800 volts at once. But they're not constant. They can't keep Christmas lights on all the time. So when Miguel sends out a shock, it basically flips this switch that makes the lights flicker a little bit. But we wanted to know: could he power those lights? Could we use electric eels to power our homes?

Kimberly Hurt: So I would want to say no. Even though the idea is kind of intriguing, they're not constantly producing electricity. So a lot of the eel's time is just resting. He's just kind of hanging out on the bottom of the tank not producing electricity.

Alex: Right.

Kimberly Hurt: It's gonna be more when he's moving around or trying to find food that he is producing electricity. So it's not constant electrical generation. If you had a whole tank full of eels, maybe you could get a little bit of constant electricity going, but I don't know that it would be worth the hassle.

Alex: Right. You'd have to have the tank, you'd have to feed the eels. [laughs]

Amelia Urry: What if you put them on a treadmill, though? Then what?

Alex: [laughs] Exactly. So yes. Like, electric eels are really cool. They're not very reliable. So it sounds like electricity from eels idea? DOA. They cannot power your house. But hold on. Before we submit our rankings, there's one more guy I want you to meet.

Tom Schroeder: Hello, my name is Tom Schroeder. I am a research associate at Harvard University, and my work seeks to develop electrical power sources out of synthetic materials that are inspired by electric eels.

Alex: [laughs] Okay. So to understand Tom's work, we have to know how the electric eel produces shocks. Eels have these specialized little cells in their body, and in these cells there's salty fluid on one side of the cell and less salty fluid on the other. And for some reason that I didn't study enough physics to understand, when you have salty fluid next to less salty fluid, the difference in the saltiness generates an electric charge. So each one of these cells is sort of like a little battery, and when the eel is resting, the charge is balanced. It's like if you put a line of batteries all together, but every other one is facing the wrong way. When the eel wants to produce a shock, though, it's kind of like stacking the batteries in a series, laying them in the right way. The charge accumulates, and voltage is produced. And that got Tom thinking. There's other times when salty water is coming into contact with less salty water.

Tom Schroeder: Basically, whenever a river flows into the ocean, there is an amount of energy that comes from just the mixing of saltwater with freshwater that is released as waste heat. And that amount of energy is equivalent to a 270-meter-high waterfall. [laughs]

Alex: And they call this blue energy. And multiple scientists are actually trying to work out how you can basically extract electricity from saltwater and freshwater coming into contact.

Tom Schroeder: The connection that we made that I think was really important was that in this kind of blue energy scheme that I had mentioned, basically what people do when they're engineering that kind of stack of membranes is building something that is functionally analogous to what is in the anatomy of the eel. It's different ions and at different concentrations, but it's the same overall idea.

Alex: Rivers dump around 37,000 cubic kilometers of fresh water into the oceans every year. If we could harness that power, setting up, I don't know, a big battery at the mouth of the Hudson, for example, that could help a lot. The scientists estimate there's about 2.6 terawatts of potential blue energy in rivers globally—that's roughly the same amount generated by 2,000 nuclear plants. But so far, that power is mostly theoretical. There was at least one plant that did get built in Norway, but it shut down in 2014 because it wasn't cost effective. Turns out the membranes that they needed to produce the power between the salty and the less salty water? Those membranes were just way too expensive. So commercial viability seems a little way off, but still it's possible, and scientists are actively researching new ways to collect blue energy that could be more stable and cost effective. All right, so there you have it: electricity from eels to the masses. [laughs] So I think it's Brian's turn to go first this time. What do you think, Brian? Viability?

Brian Kahn: I mean, this is a wild ride. I gotta say. Like, I hesitate to give it anything less than a five because I don't want Miguel Wattson's fans to come after me. I don't want to anger the Wattson stans. I don't know, I'm going to give this a one. It feels too hot to handle. I'm not ready for this.

Alex: Yeah.

Brian Kahn: I like your idea of putting, you know, a battery by the Hudson. It sounds like there are people working on that, so I wish them godspeed, good luck. But it sounds like this is a long ways from viability, so I'm gonna give it a one on the viability scale. You know, creativity wise? Very creative in an evil genius kind of way. So I feel like I gotta respect the game, evil genius game, and I'll give a four.

Alex: All right. And how about you, Amelia?

Amelia Urry: Yeah, I think this is the one on viability and a five on creativity. I think this is the split option.

Alex: Uh-huh.

Amelia Urry: If we were writing a movie, this is like the five idea that goes in there, but if we're writing our clean energy future, I don't know if this one's gonna make the cut. I think it's a one.

Alex: You don't want to wait on the eels?

Amelia Urry: Yeah. And let the eels go, you know, live their own lives. They don't have to work for us.

Alex: Exactly. All right. Now we've gone on a journey, we've heard four different ideas. Here's where the rubber meets the road. In terms of scoring, if you tally up all the scores—viability, creativity—exercise power got an 11, wave power got a 10.5, eel power got an 11, poo power got a 17.

Brian Kahn: Poo power's the future!

Alex: But I think that was because poo power had—was high both in viability and creativity. I think we were really excited about getting power from poop.

Amelia Urry: I feel like it has to be poo power. I think it has to be.

Alex: [laughs] Why does it have to be poo power?

Amelia Urry: It's just like, we already have all the pieces of that puzzle. They're already there, they're just waiting for someone to put them in the right order.

Alex: Right.

Amelia Urry: And I think, like, if you link it up with—I didn't know—he kept talking about the bedding. So if you, like, link that up with sort of, you know, yard waste. It's fall right now, the leaves have just dropped and everyone's been, like, raking them up like mad or, you know, all that stuff could go in there, all the food waste. Like, you could really just pile a lot of things that right now are just kind of waste for us into a system that would then turn into energy. That's kind of amazing. So yeah, as much as I think the other close contender for me is the waves, but I think poo is just closer.

Alex: And what about you, Brian? Now that you've heard all these ideas, are you also on team poo power?

Brian Kahn: I feel—the poo power, like, there's already a degree of viability, whereas the wave, I feel like it's a bit of an untapped market. So I think there's a lot of—there's growth potential. It might not be there yet, but with the right investors behind it, perhaps, you know, we could get somewhere with this.

Alex: The thing about the waves is that literally 70 percent of the Earth is water, right? If we can figure it out, there's a lot of energy there.

Brian Kahn: Yeah. And I also mean, you know, the fact that you have these—I mean, the Department of Energy, I know the Bureau of Ocean Management, there are major federal agencies putting money into this. And I mean, you know, they pick sometimes the wrong things, but I think the fact that they're willing to take a shot at wave power, I'll throw my lot in with them on the wave power and I'll leave Amelia the poo to hang out with.

Alex: And you all probably know better than most that all of these things that are now sort of like taking over the world, like, you know, sort of like super cheap solar and sort of super viable wind, all these things were in this place at one point, in the place that poo power and wave power are today. And so, you know, just because it doesn't exist now does not mean it couldn't exist in the next decade or two. Well, this has been quite a journey that we've gone on with you guys. I really appreciate you coming along with us.

Amelia Urry: Yeah. Thank you for inviting us on this truly wild journey. Your callers definitely get high creativity scores. They really came up with some things.

Alex: I know! They're the best.

Brian Kahn: Yeah, this is a lot to think about. [laughs]

Alex: So that wraps up our very first episode of "Electrify This." Thank you all for joining us. All right, and that brings us to our calls to action. If you want to learn more about any of the four alternative energy technologies we discussed in this episode, we'll link to some of the resources and organizations that our experts mentioned. And we'll do that in the show notes, so you can definitely check that out to learn more.

Alex: And then, you know, researching and investing in alternate energy technologies, it's important, but it is just one step in getting us on the path to renewables. Because even if you find a great new way of generating electricity, you still need to get that electricity to the people, and that requires us to rethink our electricity grid and how it works. We actually have a couple episodes about that—check out our "Party Like It's 2035" and also "How We Got Our Grid, And How We Get a Better One." Those two episodes talk all about the grid.

Alex: And that's not the only thing you can do to get electrification off on the right track. We also know multiple cities are already aiming to run on 100 percent renewable energy. The Sierra Club has a map of those cities, so you can see their action plans or even join a local campaign. And if you want to start right in your very own home, we will also link to a handy guide from the group Rewiring America on how to electrify everything in your house—from your light bulbs to your heat pump, everything. You could also check out organizations like Grid Alternatives, which works to get solar power to underserved communities, or the Footprint Project, which helps people affected by natural disasters access renewable energy sources as they recover.

Alex: And again, we'll link to all of these sites and resources in our show notes and in our newsletter. Our newsletter, you ask? Well, you can subscribe by going to our website at How2SaveaPlanet.show—that's How 2—the number 2—SaveaPlanet.show. And as always, you can follow us on social media. Our handle is how2saveaplanet on Instagram and Twitter.

Alex: How to Save a Planet is a Spotify original podcast and Gimlet production. It's hosted by me, Alex Blumberg. This episode was produced by Hannah Chinn. The rest of our reporting and producing team includes Kendra Pierre-Louis, Rachel Waldholz and Anna Ladd. Our supervising producer is Lauren Silverman with help from Katelyn Bogucki. Our editor is Caitlin Kenney. Our intern is Nicole Welch. Sound design and mixing by Peter Leonard, Lonnie Ro and Emma Munger, with original music by Peter Leonard, Emma Munger and Bobby Lord. Our fact checker for this episode is Claudia Geib. Thanks to all our listeners for your fun, creative energy generation ideas. Talk to you all next week!