this post was submitted on 08 Dec 2025
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Nuclear engineer Lonnie Johnson worked on NASA's Galileo mission, has more than 140 patents, and invented the Super Soaker water gun. But now he's working on "a potential key to unlock a huge power source that's rarely utilized today," reports the Atlanta Journal-Constitution.

Waste heat... The Johnson Thermo-Electrochemical Converter, or JTEC, has few moving parts, no combustion and no exhaust. All the work to generate electricity is done by hydrogen, the most abundant element in the universe. Inside the device, pressurized hydrogen gas is separated by a thin, filmlike membrane, with low pressure gas on one side and high pressure gas on the other. The difference in pressure in this "stack" is what drives the hydrogen to compress and expand, creating electricity as it circulates. And unlike a fuel cell, it does not need to be refueled with more hydrogen. All that's needed to keep the process going and electricity flowing is a heat source.

As it turns out, there are enormous amounts of energy vented or otherwise lost from industrial facilities like power plants, factories, breweries and more. Between 20% and 50% of all energy used for industrial processes is dumped into the atmosphere and lost as waste heat, according to the U.S. Department of Energy. The JTEC works with high temperatures, but the device's ability to generate electricity efficiently from low-grade heat sources is what company executives are most excited about. Inside JTEC's headquarters, engineers show off a demonstration unit that can power lights and a sound system with water that's roughly 200 degrees Fahrenheit — below the boiling point and barely warm enough to brew a cup of tea, said Julian Bell, JTEC's vice president of engineering. Comas Haynes, a research engineer at the Georgia Tech Research Institute specializing in thermal and hydrogen system designs, agrees the company could "hit a sweet spot" if it can capitalize on lower temperature heat...

For Johnson, the potential application he's most excited about lies beneath our feet. Geothermal energy exists naturally in rocks and water beneath the Earth's surface at various depths. Tapping into that resource through abandoned oil and gas wells — a well-known access point for underground heat — offers another opportunity. "You don't need batteries and you can draw power when you need it from just about anywhere," Johnson said. Right now, the company is building its first commercial JTEC unit, which is set to be deployed early next year. Mike McQuary, JTEC's CEO and the former president of the pioneering internet service provider MindSpring, said he couldn't reveal the customer, but said it's a "major Southeast utility company." "Crossing that bridge where you have commercial customers that believe in it and will pay for it is important," McQuary said...

On top of some initial seed money, the company brought in $30 million in a Series A funding in 2022 — money that allowed the company to move to its Lee + White headquarters and hire more than 30 engineers. McQuary said it expects to begin another round of fundraising soon.

"Johnson, meanwhile, hasn't stopped working on new inventions," the article points out. "He continues to refine the design for his solid-state battery..."

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Y'all poopooing on this think about the amount of waste heat generated by industrial processes. This captures that and uses it to reduce the overall demand on the grid.

[–] kilgore_trout@feddit.it 9 points 6 days ago (2 children)

Earth needs more energy

…does it?

[–] SpaceMan9000@lemmy.world 16 points 6 days ago (2 children)

Yes, even without ai it's better for people to move away from gas. Electric cars, heating and cooking dinner is all moving to electricity.

[–] phutatorius@lemmy.zip 1 points 5 days ago

And there's no reason for widespread adoption of AI besides a massive hype cycle driving a speculative bubble.

[–] loonsun@sh.itjust.works 1 points 6 days ago

Yeah, having an abundance of nuclear power is good regardless of the economic system as long as it's done safely.

[–] jj4211@lemmy.world 3 points 6 days ago

Hypothetically, any energy harvested from a zero-emission strategy might at least displace combusting some hydrocarbons.

[–] agent_nycto@lemmy.world 7 points 5 days ago

This dude rules and is a freakin hero. Also love that the greatest invention was pressurized water device and this is pressurized hydrogen device.

[–] palmtrees2309@lemmy.world 4 points 5 days ago

Sun is distributing free energy maybe gathering that will help us. But problem is big petro and coal cant let that happen as there is no monopoly on sun.

[–] lowspeedchase@lemmy.dbzer0.com 5 points 6 days ago* (last edited 6 days ago) (2 children)

with water that’s roughly 200 degrees Fahrenheit

barely warm enough to brew a cup of tea

That is scalding hot water brother LOL

[–] jj4211@lemmy.world 7 points 6 days ago (1 children)

It is scalding hot, but I think the key takeaway is that it's not hot enough to boil into steam, which is our current go-to for harvesting energy from heat.

So after you do your steam turbine and you are left with not-quite boiling water, by today's standards it is useless for further harvesting for electricity. If this article is as-advertised (a big if), then we can harvest more, adding efficiency to any process that boils water to turn a turbine.

[–] lowspeedchase@lemmy.dbzer0.com 1 points 5 days ago (1 children)

Yup I get it, just don’t like marketing speak and downplaying what we are talking about - it takes a ton of joules to get water that hot and it’s dangerous.

[–] HertzDentalBar@lemmy.blahaj.zone 1 points 5 days ago (1 children)

The water in this case is not being heated up for this, it's waste heat man. It's already going to be hot.

Everything is dangerous. That's why we have certification and training.

[–] lowspeedchase@lemmy.dbzer0.com 1 points 5 days ago (1 children)

Where did I say the opposite of anything you are talking about?

The concern for how much energy it takes to heat up the water.

[–] deHaga@feddit.uk -1 points 5 days ago (1 children)

It's 95 Deg C. That's not hot enough for a proper cup of tea you add milk to. It should be boiling.

[–] logi@lemmy.world -1 points 5 days ago (1 children)

And yet it's too hot for a proper cup of green tea.

[–] deHaga@feddit.uk 2 points 5 days ago* (last edited 5 days ago) (1 children)

It's still below boiling point, which is the literal point. It's not using super heated steam to turn a turbine

[–] logi@lemmy.world -2 points 5 days ago* (last edited 5 days ago) (1 children)

If that's the literal point, and worth getting aggro about, then why on God's green earth are you talking about tea? And milk?!?

[–] deHaga@feddit.uk 1 points 5 days ago (1 children)

Maybe read the fucking article?

[–] logi@lemmy.world -3 points 5 days ago* (last edited 5 days ago) (3 children)

It's probably time to put the kettle on and stay away from the Internet, and perhaps other people in general, until you're feeling better.

[–] alphabethunter@lemmy.world 2 points 5 days ago

Nah, you have interpretation problems and a little cursing on the internet is quite inoffensive.

[–] deHaga@feddit.uk 1 points 5 days ago

Lol, I'm not mad, I just like using the Anglo Saxon vernacular.

The point OP was making is that 95 degrees is scalding hot. For energy purposes this is very low, steam turbines operate at much much higher temps, from 300-600 Deg C

[–] JackbyDev@programming.dev 0 points 5 days ago

You should take your own advice.

[–] phutatorius@lemmy.zip 1 points 5 days ago (1 children)

The Earth doesn't need a fucking thing it doesn't already have, except for a cleanup of human-generated pollution.

Most of the new demand for energy is to run LLMs that nobody actually needs.

[–] alphabethunter@lemmy.world 1 points 5 days ago

I hate this shit as well. People use "The Earth" to make it sound good for the environment, but it's actually just human greed we're always talking about. Take sustainability for example, you ask teens about it, and a lot of them will say it's about saving the environment. It's not. It's about trying to sustain capitalism and our consumerist lifestyle to go on forever while pretending to give a fuck about the environment.

I always thought there was more to be extracted from waste heat. Similarly I wonder if modern techniques could extract more from mine waste instead of opening more mines.

[–] Nindelofocho@lemmy.world 0 points 6 days ago (3 children)

So like a little removed from this but I always wondered why cant we harvest energy from busy buildings where people are closing and opening doors all the time? The doors typically already even have a motor on them to be handicap accessible and need to slow close anyways. If anything it could generate enough electricity for at least a couple lights or office computers

[–] frongt@lemmy.zip 10 points 6 days ago (1 children)

The cost of installing the generator and wiring is far higher than the energy recouped.

[–] Nindelofocho@lemmy.world -1 points 6 days ago* (last edited 6 days ago) (2 children)

That doesent make sense though because automatic doors and handicap accessible doors already have motors which also can be generators and are otherwise connected to power??

Like the only complexity I can think of would be smoothly and safely delivering the power back to the buildings grid but we definitely have overcome these complexities in other applications

Edit: has there been a study or at least some math done on how much force goes into opening and closing doors in commercial buildings?

[–] Corkyskog@sh.itjust.works 4 points 5 days ago (1 children)

Think about this... if it were profitable most white collar workers would be riding a stationary bike with a generator, much more energy than a door opening.

A stationary bike over an 8 hour workday would produce probably ~1kWh, so like 19 cents given the US average. That wouldn't even pay for maintenance and replacement parts for the devices.

[–] Nindelofocho@lemmy.world -1 points 5 days ago (1 children)

Its less about the profit and more about offsetting costs. Yes one door wouldnt be really worthwhile but in this circumstance you’re using parts you already need to maintain and run(door pistons and accessibility) and the complexity added to the system could be bypassed should it fail without impacting that core operation

[–] frongt@lemmy.zip 2 points 5 days ago

No costs will be offset by this. The device will be replaced multiple times before it ever breaks even on the implementation cost.

[–] jj4211@lemmy.world 1 points 6 days ago (1 children)

Well then you need to handle backfeeding all sorts of circuits, which is generally a pain to the extent it works. But it also would barely do anything.

[–] Nindelofocho@lemmy.world 0 points 5 days ago (2 children)

Yes as you typically do with most forms of generation. One door wouldnt do much but multiple doors opening and closing constantly all day surely has the potential to generate some amount of energy.

Ive been in places where the door basically doesent stop moving for hours at a time, even if the door doesent close fully its still moving by someone either opening it wider or it coasting back towards closed position. Compliant exterior doors are typically set to take about 8.5-10lbs of force to open. Im not super good at math but surely that much “weight” moving constantly could generate some electricity. There are small wind turbines that move with less force constantly

[–] jj4211@lemmy.world 4 points 5 days ago (1 children)

So assuming 10 lbs of force, as measured 1 meter away from the hinge, you have about 44.5 Nm of torque. Assuming each door opening was about 90 degrees, then you have about 70 Joules per door operating event.

Each door opening would have a physical theoretical max of 0.02 watt-hours.

Assuming you spent 8 hours opening a door every 10 seconds constantly, then you have 58 watt-hours of energy at the end of the day if you had 100% efficient generators. One typical solar panel would hit that in under 15 minutes in real-world energy collection, not theoretical.

[–] Nindelofocho@lemmy.world 0 points 5 days ago

Good soup thank you very much for doing the math. I was struggling

[–] Poojabber@lemmy.world 1 points 5 days ago (1 children)

Most doors that are controlled for handicap accessability are control using a hydraulic cylinder that costs hundreds of dollars, and not a motor. Any motorized doors cost way way more than that.

I had the same thought when I was younger about putting generators attached to a bouy in the ocean, which has waves constantly and would generate power all day. Just like your door idea, it would work and would make power, but it wouldnt turn a profit. Its too expensive for the output you would get in return. So.... yeah... we are gonna continue to burn fossil fuels for now cause its the cheapest.... once we deplete enough of them that it gets more expensive than something else, we will switch to that until we destroy the world, or skynet takes over and we become the next power source.

[–] Nindelofocho@lemmy.world 1 points 5 days ago (1 children)

Hey isint that buoy or at least power generated by waves idea something thats currently kinda being done though?

Kinda but it looks like a snake, it uses wave action between each segment to generate power. A single buoy going up and down can't do much, you're better off with solar which is what we do.

You'd probably generate less electricity then would be required to create the calories needed to cover opening the now slightly more resistant door.

[–] SocialMediaRefugee@lemmy.world 0 points 5 days ago (1 children)

You'd make it harder to open doors and slower to close, wasting heat in winter and ac in summer.

[–] Nindelofocho@lemmy.world 0 points 5 days ago (1 children)

Almost every commercial door has a door closer rhat does exactly this?

The benefit is trivial compared to the cost

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