How a NASA Engineer Turned a Toy Into Clean Energy

[00:00:00] Matt Farrell: Hot car engines, factory exhaust stacks, even power plants. When fuel gets used, there's heat left over, and unless you want to fry an egg on the hood of your Mazda after zipping around the block, that extra heat is waste, just gone, useless. But what if there was a way to channel it? Like literally? There's a new heat engine that transforms waste heat into electricity, even the low-grade stuff that today's best systems can't touch. It has no moving parts, none, and it could be on track to become as efficient as physically possible. But maybe the craziest thing about it, it was dreamed up by the same nuclear engineer who invented the super-soaker. His name is Dr. Lonnie Johnson, and the engine is called the Johnson Thermo-Electrochemical Converter, or JTEC. And while the JTEC is still in commercial development, it's an exciting enough project that I wanted to put it through its paces. Is this the engine that turns waste heat into something useful, and will the JTEC make an even bigger splash than the super-soaker? I'm Matt Farrell, welcome to Undecided. This video is brought to you by Jackery. First off, I gotta apologize for my voice, I'm getting over chest cold, so I'm sorry. Imagine being told that you're hot your whole existence. But when it comes time to make use of that hotness, suddenly you're just not the right kind of hot. It's tragic really. But that's the state of waste heat today. There's an incredible amount out there, but most of it isn't usable. Take industry. It uses a third of all the energy on the planet, and it wastes a huge chunk of that as heat. Up to half just drifting away. We're talking exhaust fumes, heat from cement kilns and steel mills, commercial bakeries, refrigeration and data centers. Most of this extra heat isn't even that hot. It's low temperature heat between 100 and 200 degrees Celsius, which is about 200 to 400 degrees Fahrenheit. That's hot enough to make a very dangerous cup of coffee, but not quite hot enough to turn an industrial steam turbine. Technologies do exist to generate electricity from low-grade heat like this, but the existing tech is expensive and it's not very efficient. That's why you don't see it everywhere. It's not just industrial heat that's not hot enough. A lot of geothermal sources aren't hot enough to efficiently generate electricity either. The JTEC offers a potential pathway to make use of all this excess, to make running on fumes an asset rather than liability. And right now it's promising enough that even energy companies are taking note. [00:02:13] Dr. Lonnie Johnson: Our major investor is an oil and gas company that came to us looking for technology because they could convert the low temperature heat and abandoned oil wells into power. About 20% of the abandoned oil wells in the country could supply all the US power needs. [00:02:28] Matt Farrell: There's a lot of wasted potential energy out there. So back to our question, is this finally the engine that turns waste heat into something other than waste? Well, to answer that, we need to know two things. How does JTEC actually work and how efficient can it really be? The JTEC works differently than traditional engines, a lot differently. First, it doesn't use fuel to create heat. It uses ready-made heat sources like industrial waste or geothermal. That means no emissions. That heat isn't turned into motion the way nuclear, coal, or even traditional geothermal power plants boil water into steam to spin a turbine to generate electricity. This middle step is cut out. Instead, the JTEC converts heat directly into electricity with no moving parts, none. That means less mechanical friction, less wear and tear, and potentially fewer maintenance headaches. The JTEC heat engine cycles hydrogen gas between a heat source and a cooler heat sink that can be at room temperature. As the hydrogen moves between the hot and cold, it isn't consumed like a fuel. It's split into protons and electrons, and then it's put back together into a hydrogen gas, again and again. Dr. Johnson's team explained to me how this wild process works, but we'll get to that in a second. First, I want to introduce the NASA engineer responsible for the JTEC. He's kind of a genius. Dr. Lonnie Johnson was an inventor decades before he came up with a super soaker. In high school, he built a robot named Linux. This was all the way back in 1968, and so it was powered by compressed air and controlled by jukebox switches. And for memory, it had reel-to-reel tape recorder. I mean, just look at this thing. It's absolutely awesome. [00:04:00] Dr. Lonnie Johnson: Back in the 60s, no one had robots back then, but I was watching robots on TV and nobody told me that those had people inside, so what the hell? I just have to try to build one. [00:04:12] Matt Farrell: Dr. Johnson trained as a mechanical and nuclear engineer, taking jobs at Oak Ridge National Laboratory in Tennessee and the Air Force Weapons Laboratory. And that was before working on the Galileo and Cassini missions at NASA's Jet Propulsion Laboratory in California. But that wasn't enough to occupy his mind, and so he'd go home and tinker. He was working on a new kind of refrigeration system using water instead of ozone-destroying CFCs when he saw how fast and far a nozzle he'd machined could shoot water across the bathroom. [00:04:38] Dr. Lonnie Johnson: And I thought, you know, this is a lot of fun shooting this. Maybe I should, instead of having this thing hooked to the bathroom sink, what if I could make a toy gun that could hold a lot of water at high pressure and a little powerful stream coming out of it? So that was the genesis of the idea for the Super Soaker. [00:04:55] Matt Farrell: Dr. Johnson put together his first prototype from an empty soda bottle and PVC pipe with nylon tubing and homemade valves. These water guns use a pump action to compress air to drive a powerful stream, and they changed the game. The neighbor kid's Super Soaker blew away my dinky little water pistol I had back then. Over a billion dollars of Super Soakers have been sold since the 1990s. And Dr. Johnson's share of that money? Well, he's used it to advance other innovations like the JTEC. It's maybe the most clever crowdfunding campaign of all time. The JTEC has been in development a long time. Dr. Johnson thought up the idea in 2003, long before some of the materials that it uses even existed. And it wasn't until 2020 that he brought together a team of engineers at JTEC Energy in Atlanta, Georgia to make it happen. The question now is whether the JTEC is ready for liftoff. But we have to get to the question, how does it even work? And we'll get to that in just a second, but Johnson's engine is still years away from powering anything in your home. If you want a backup power that's ready today, that's where today's sponsor, Jackery, comes in. This is the new HomePower 3600 Pro Max, and I've got my entire office running off of it. Computer, monitors, speakers, and lights. Nothing flinched. This has its automatic backup kicking in under 10 milliseconds, faster than your eye can see. Inside is a 3.6 kilowatt hour lithium iron phosphate battery. It's built for 6,000 cycles, 4,000 watts of output, and handles both 120 and 240 volt circuits in one unit, which means it can power hydra stuff a regular portable battery can't, like a dryer, a well pump, even charge your EV. 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Now back to the engine that turns waste heat into power. So what's the secret for making electricity with no moving parts? Electricity is essentially electrons flowing through a circuit. The J-TECH gets those electrons from hydrogen gas, and unlike in a combustion process, hydrogen isn't a fuel, which means to say that it isn't used up. Hydrogen loans those electrons to the circuit, where they provide electrical current, and then hydrogen just takes them back. The genius of the J-TECH is forcing hydrogen gas to loan those electrons temporarily. And the part of the J-TECH that makes that happen is a proton exchange membrane. A membrane is like airport security. It sets the rules for how to get through. At J-TECH airport, hydrogen gas has to put its electrons through the baggage scanner and pass through the metal detector, which is the membrane, and it passes through separately as two protons. And that conveyor belt? That's the electric circuit. That's the electrons making their journey. That's the electricity. From the other side of the metal detector, protons pick electrons back up and become hydrogen gas again. So you've got a membrane that splits hydrogen, lends the electrons to an electrical circuit, and then brings everybody back together again. If this is airport security, where is hydrogen flying? Someplace cooler, because all that waste heat is driving hydrogen through the membrane. With enough heat, gases expand, and that puts pressure against the membrane. Think of a plastic bottle with soda left in a hot car. It's rock hard when you return to it, since the heat drives up the pressure of the gases. The only way to relieve that pressure is for the hydrogen to pass through the membrane to the low pressure zone on the other side. Like 100 pounds per square inch dropping to just 0.01 pounds per square inch. The pressure is off. These hydrogen atoms are on vacation moving towards that cooler zone. The trouble is, they still have to get to work next Monday. And to fly home, they've got to pass through another security checkpoint, which is another membrane. And that, as we all know from dragging ourselves home from vacation, is a lot of hard work. These hydrogens have to move from their cooler, low pressure vacation back to the high pressure work environment and back to the heat. The good news is, the vacation pays off. The energy gained from going on vacation is more than enough energy to get back to work. Our hydrogen returns from its trip relaxed, ready to work, and with a couple of stories for the water cooler. Or in JTEC terms, the voltage produced on the hot side is more than enough to drive the reverse reaction on the cold side, with plenty left over as free electricity. Of course, the bigger lesson as we head into summer is we all need some vacation, even if it's just cooling off at the pool. That's Matt's fifth law of thermodynamics. The JTEC isn't impressive just because it has no moving parts, or because it splits hydrogen and then puts it back together again. It's impressive because of what it could mean for efficiency. And efficiency is the whole ballgame. If waste heat is going to stop being waste, the JTEC has to convert it better than anything we already have. So how does it stack up? Well, on paper, the JTEC could convert heat into electricity with less wasted energy than the traditional route of burning fuel, boiling water into steam, and spinning turbines to generate electricity. [00:10:18] Dr. Lonnie Johnson: So instead of pistons and turbines, I use electrochemistry to do the compression and expansion process, and instead of steam, I'm using hydrogen. [00:10:27] Matt Farrell: In 2020, a laboratory version of JTEC reached 17.1% thermal efficiency, with a heat source at 200 degrees Celsius, or about 400 degrees Fahrenheit. For those operating temperatures, that's nearly half of Carnot. And Carnot is the maximum theoretical efficiency for a heat engine turning heat into electricity. For comparison, the most popular low temp heat to electricity technology around achieves around 12-13% efficiency at these temperatures, which is around one-third of the Carnot ceiling. Johnson's goal for JTEC is to reach about two-thirds of Carnot, and he says his team now has test data indicating that it's achievable. Not only is the JTEC an efficient heat engine, it's a heat engine that can run backwards or forwards, and when the JTEC runs in reverse, it cools. It uses electricity and becomes a refrigeration system. The ability to run in both directions is pretty cool, but what I want to know is whether we need to cool our expectations for the JTEC in the near term. Because it won't matter if the heat engine works technically if it can't compete economically. Tech is cool, but price is king. When working with high temperature heat around 500 to 600 degrees Celsius, the JTEC works with a ceramic membrane. With low temperature heat, like for waste heat or geothermal, the JTEC uses a thin, flexible membrane that's sandwiched between support layers. These membranes have to be strong enough to hold that pressurized hydrogen gas. The higher the pressure, the better – that's a lot of pressure for just a little membrane. Still, Dr. Johnson is optimistic about the JTEC's cost per megawatt-hour of electricity. [00:12:03] Dr. Lonnie Johnson: In about five years, we'll be competitive with other systems, but 10 years from now, our projection is that we'll be the lowest cost energy system in the world. [00:12:12] Matt Farrell: There is a scale-up challenge. Waste heat isn't always easy to gather and shoot towards a membrane. There are a lot of barriers to collecting that 20 to 50% of industrial energy that's lost as heat. Sometimes the waste heat is from batch processes, so you're not getting a round-the-clock source to power the JTEC. Other times, waste steam has chemicals that need to be filtered out, so the system gets more complex. And just capturing heat off the surfaces of industrial equipment isn't necessarily an easy challenge to overcome. Do you know how to collect heat radiating from an abandoned oil well? I sure don't. Right now, the company is targeting 250 kilowatt units, a size that competes with generators. The first commercial unit is being built right now for a major southeast utility company. [00:12:51] Dr. Lonnie Johnson: But our initial markets will be waste heat from existing engines, particularly turbines and things like that, gas turbines. [00:12:58] Matt Farrell: That makes sense. Many natural gas power plants already send their hot exhaust through a second heat engine designed to generate electricity at a slightly lower temperature. With a device like the JTEC, another cycle working with cooler leftover heat could squeeze a bit more electricity out of the same initial fuel. So back to where we started. Is this finally the engine that turns waste heat into something valuable? Well, here's my take. The physics is real. The efficiency claims hold up in the lab. The question is whether membranes can be made cheaply enough at scale. If Johnson hits his cost targets in five years, this is the most important heat engine since the steam turbine. It might just be the ticket to salvaging industrial waste heat and even capturing geothermal energy from abandoned oil wells. Johnson has been working to commercialize the JTEC for almost a quarter century. But where he could just mill a nozzle and some valves in his workshop to demonstrate the super soaker, the technology needed for the JTEC has required significantly more effort. He's had to persevere. [00:13:53] Dr. Lonnie Johnson: I often ask myself, would I have started this if I had known all the obstacles and challenges? Probably because I would have been bored otherwise. [00:14:02] Matt Farrell: But what do you think? Is this the invention that finally turns low temp waste heat into a hot commodity? Or is it all hot air or hydrogen? If you're interested, I'm going to be releasing my full conversation with Dr. Johnson on my Still To Be Determined podcast, and you can also check out extended cuts of many of my videos over on Patreon, like a deeper look at how JTEC works. If human-written and research videos matter to you, Patreon support helps a ton. The link's in the description if you'd like to join, but just watching, subscribing, and turning on notifications is awesome. Keep your mind open, stay curious, and I'll see you in the next one.