Can This Simple Invention Convert Waste Heat Into Electricity? (ajc.com)
(Sunday December 07, 2025 @11:36PM (EditorDavid)
from the power-plays dept.)
- Reference: 0180327037
- News link: https://hardware.slashdot.org/story/25/12/08/0236259/can-this-simple-invention-convert-waste-heat-into-electricity
- Source link: https://www.ajc.com/business/2025/11/earth-needs-more-energy-atlantas-super-soaker-creator-may-have-a-solution/
Nuclear engineer Lonnie Johnson worked on NASA's Galileo mission, has more than 140 patents, and invented the [1]Super Soaker water gun. But now he's working on "a potential key to unlock a huge power source that's rarely utilized today," [2]reports the Atlanta Journal-Constitution . [3]Alternate URL here .]
[3]Alternate URL here .]
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, [4]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 [5]beneath the Earth's surface at various depths. Tapping into that resource through abandoned oil and gas wells — a well-known [6]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..."
[1] https://en.wikipedia.org/wiki/Super_Soaker
[2] https://www.ajc.com/business/2025/11/earth-needs-more-energy-atlantas-super-soaker-creator-may-have-a-solution/
[3] https://www.seattletimes.com/business/earth-needs-energy-atlantas-super-soaker-creator-may-have-a-solution/
[4] https://www.energy.gov/eere/iedo/waste-heat-recovery-basics
[5] https://www.energy.gov/eere/geothermal/geothermal-basics
[6] https://www.energy.gov/eere/geothermal/wells-opportunity
Another "miracle" machine (Score:2)
by gweihir ( 88907 )
I will be interested when they have a working prototype that comes close to the claimed efficiency. I predict that will not happen.
Can this simple device avoid all laws of physics? (Score:2)
by Mr. Dollar Ton ( 5495648 )
You betcha, it was developed by the new method of vibe engineering.
In Japan 20 years ago : Low-temperature turbines (Score:2)
by thesjaakspoiler ( 4782965 )
They had closed loop turbines filled some gas that were using hot water (100F / 40C) from hot springs to generate electricity for a whole town.
20 years ago ...
Normally I'd write most of that off as fluff (Score:2)
by 93 Escort Wagon ( 326346 )
Worked for NASA... *yawn*. Holds 140 patents... yeah, so what?
But this dude also invented the Super Soaker - now THAT's legit guy cred!
claims (Score:4, Interesting)
Johnson claims 40 - 60 % efficiency with large temperature spread of 600 degrees C.. and that's beautiful and wonderful.
Thus far experiments at lower temperature differences have been done, I see on net 180 degrees with 17 percent which actually is ok too. The theoretical max there would be 38 percent.
But, anything near the 40 to 60 percent theoretical value hasn't been demonstrated in repeatable experiment, he's working up to that. So, is Johnson just overhyped about the invention or can he (or anyone) deliver? for that matter, even 20 percent at lower temp differences might be good for a lot of things anyway.
Re: (Score:1)
I've seen tenth of a watt with 50 degree C temperature differential reported. So on a brisk winter day of -17 C you'd need 50 friends or johns or M type gimps to prostrate themselves in a circle with their exposed rumps in the air towards the center, and from your pivot man position in the center jam a silicone heat sink greased JTEC up each their asses to get the 5W to charge a smartphone.
Re: (Score:1)
I've just realized that with the M-type gimps in typical configuration you could use a modified ball gag to augment the anal collection and only need 25 of them. Proper gimpsuits for the outdoor temperature would ensure a longer collection period to avoid hypothermia before the phone is charged.
Re:claims (Score:4, Insightful)
For the example in TFS of 200F water and assuming room temperature exhaust, Mr. Carnot says that the max possible efficiency is less than 20%. Any real world engine, including this one, probably ends up at a low-to-mid single digit percent efficiency. IOW, the vast majority of the heat would still be wasted.
The operator of the facility generating the waste heat might get more energy savings at lower cost by tweaking their processes to be a few percent more efficient in the first place, instead of trying to recover this low-grade energy source with an elaborate engine and plumbing.
Re: claims (Score:1)
Playing devil's advocate, there may be some give on the "assuming room temperature" part. I recall reading about "negative thermocouples" a while back where they played tricks with materials and geometry to get a high view factor into cold space straight from the ground and used basically 2.7K of the sky as a heat sink.