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Super Soaker Inventor Hopes to Double Solar Efficiency
mattnyc99 writes "With top geeks saying photovoltaic cells are still four years away from costing as much as the grid, and the first U.S. thermal power plant just getting into production, there's plenty of solar hype without any practical solution that's efficient enough. Until Lonnie Johnson came along. The man who invented the Super Soaker water gun turns out to be a nuclear engineer who's developed a solid-state heat engine that converts the sun's heat to electricity at 60-percent efficiency—double the rate of the next most successful solar process. And his innovation, called the Johnson Thermoelectric Energy Conversion (JTEC) system, is getting funding from the National Science Foundation, so this is no toy. From the article: 'If it proves feasible, drastically reducing the cost of solar power would only be a start. JTEC could potentially harvest waste heat from internal combustion engines and combustion turbines, perhaps even the human body. And no moving parts means no friction and fewer mechanical failures.'"
Well, if he's oxidizing his hydrogen, I'd have to say he's all wet.
The higher the technology, the sharper that two-edged sword.
Energy efficient photovoltaic cells is fun and all, but clearly he's better qualified to invent nuclear powered Super Soakers.
And I think I speak for all of the geek fraternity when I say we'd prefer them over some poxy solar panels.
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The upside is that- like the Super Soaker- these panels will be far more efficient than their weedy predecessors.
The downside is that- like the Super Soaker- they'll only be available in eye-searingly garish combinations of purple, red and fluorescent green and yellow.
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It may be "oxidized" as in the opposite to "reduced". See also http://en.wikipedia.org/wiki/Redox
(I haven't RTFA to figure out for sure, but if they're talking "hydrogen" on one side of a reaction and "proton/electron" on the other, it seems plausible on first blush.)
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By that logic geothermal power plants wouldn't exist.
Literalism isn't a form of humor, it's you being irritating.
The article doesn't say the device is good for 60%, it states IF they are able to design it to work with with high-temperature ceramics, and IF it is able to reach 600C, then CARNOT efficiency is 60%, of which this device will obtain some fraction.
I didn't see any details on how this is any better than century-old heat engine ideas, unless the solid state design allows dirt cheap mass production, in which case he might be onto something...
Normally I would agree with you here and while IANAP (Physicist) I think you are not interpreting what he is saying properly.
He's not saying he found a more efficient solar cell (a doubling of that would be high on the BS scale). He is stating that he has created a new evolution of the Stirling Engine http://en.wikipedia.org/wiki/Stirling_engine.
From what I've read he looks to be on the up and up but again IANAP. Obviously since he has yet to have a production model we need to take it with a grain of salt but it looks very promising. *Crosses fingers*
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As I understand it, there's only a violation if that someone claims they can use ALL of the heat to do work (thermal efficiency of 1). If some heat is still being dispersed into a cooler temperature environment, it's still perfectly doable. After all, are you going to tell me you can't use waste heat from the ICE to heat up some water?
I'm not an expert in the subject (I'm an electrical engineer, so I've only gotten very basic freshman-level introductions to the laws of thermodynamics), but I think there's a well-known upper bound to how efficient recovery of heat to do work can be. Some googling led to wikipedia which tells me that upper bound is the efficiency of the Carnot Cycle. Apparently it's not quite possible to reach it, but you're not violating thermodynamics if you're below it.
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That's a nice theory, but it doesn't actually work in practice.
There is a limit to how much water is naturally evaporated from the ocean each year (far, far less than we're dumping into it) and rained down onto solid ground. There is a limit to how quickly water absorbed by the soil will leech down into the aquifers it was drawn from (it takes centuries) and that's where most of our water supplies comes from.
And as for location, there's no place on earth where the rainfall would possibly exceed the needs of a densely packed urban population, without conservation. The troubles Atlanta is having are just a start. Being located in the desert merely brings the problem to the forefront more quickly.
Look at the farm-packed interior of the US, and you'll find ridiculous quantities of water being used, all drawn from a gigantic aquifer, which is now being dramatically drawn down, with no sign of replenishment. You're welcome to go tell them they're just imagining it, when they run out of water supplies.
I'd gamble that, over the next decade, cities all across the US will have to begin copying the water conservation measures that have long been in-use in the southwest. And if they don't, the cost of water is going to go through the roof, as the expense for finding new supplies, and building new recycling facilities, goes through the roof.
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No, I was merely pointing out that "oxidized" doesn't have to mean "oxygen" or "that crud you think of on old metal", that in fact there is a technical meaning to the term the average software engineer who took one freshman level science course a decade ago -- which may not have even been chemistry -- might not connect with. Ionization and oxidation/reduction are in fact closely related terms, which the wikipedia link was meant to illustrate. If you compare the two entries ("Redox" and "Ionization"), I think you'll see the connection. Describing the process as oxidation and the effect as ionization is not a priori incorrect.
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As I read it, the hydrogen is cycled between the hot and cold sides of the cell. You don't need any more than the initial charge, just like the refrigerant in an air conditioner.
What actually happens is the hydrogen is ionized, meaning the protons which make up the nucleus of hydrogen are separated from the electrons. The protons pass through a proton-permeable membrane and flow to the cold side through a tube. The electrons are collected by anodes and forced to travel through an electrical load to the other side in order to recombine with the protons.
I'm honestly not sure of the specific details beyond that. I suspect hydrogen is used because it consists of only a proton and an electron. No pesky neutrons getting in the way and sapping energy with their mass without contributing a charge. I have no idea how they deal with hydrogen embrittlement or anything like that, because I suspect it would be a worse problem dealing with ionized hydrogen, but it may be a surmountable one.
Based on how little information there is on the webpage, I'm guessing this project isn't very far along. At face value it sounds technically feasible, but I'll wait until they start reporting actual performance data to get excited about it.
This device runs on the same principle as a Stirling engine and it shares the same theoretical efficiency: (Hot temp) / (Hot + Cold temp), all in Kelvins.
According to TFA, their first prototype is limited to 200*c because of material concerns. If they were to draw ice-cold water from the deep ocean as the cold side, it could theoretically acheive 473 / (473 + 273) or 63% efficiency. They talk about future materials allowing a hot side of 600*c, which despite being nearly twice the absolute temperature would only raise theoretical efficiency to 76%. Some sort of exotic oxide ceramic that could run at 1500 or 2000K would only add another 10% or so.
What fraction of that efficiency this or other engines acheive depends on the design. I believe the most efficient toy stirling engines can reach 90-96% of Carnot efficiency.
Issued 1 year ago, this patent describes this system in great detail. I am doubtful it can work. The electric current out of the hot end of the device is less than or equal to the current in to the cold end (since the H circulates and each passage thru either side consumes or generates one electron). To create more electric power out than goes in, the proton exchange membrane would have to create significantly higher voltages at high temperature than at low temperature. But I believe the membrane voltage is pretty much limited to the ionization potential of H, and that is not going to change significantly over temperature). Lonnie Johnson sort of weasel-words around this in column 4 lines 30-50 of the patent body. This glossing over of detail is, to me, the most damning evidence (I am a PhD physicist with 89 issued US patents).
It's a popular concept in some circles: Use affordable high-tech devices to let folks in the developing world have a better life.
An example are cell phones. They've brought connectivity to folks in even isolated villages who could not dream of getting a land line.
Or the "life straw," a simple, cheap, but high-tech gadget that filters the filth and germs from streams. It's literally a straw.
Or a simple solar-charged LED light. Hang it outside your hut in the day, bring it in at night so the kids can study or mom can make extra money doing piecework.
A sturdy, self-contained solar electrical generator could act as an adjunct for a decentralized high-tech low-budget infrastructure. You'd use it to charge cell phones, XO Laptops (and their adult equivalent), and so on.
If he is getting NSF funding then his stuff has survived an NSF peer review panel or more. I work at NSF and I can tell you that scientists that sit on NSF panels (BTW they don't work for NSF but are asked to come) don't have a habit of rubber stamping stuff they think is BS. The Ego's involved don't allow it. If it is truly worth funding then some serious people have looked at his proposal and the science behind it.