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.'"

Not sure about this...

As an excerpt from his web page states;

"On the high-pressure side of the MEA, hydrogen gas is oxidized resulting in the creation of protons and electrons"

Shouldn't that be ionized?

Re:Not sure about this...

Well, if he's oxidizing his hydrogen, I'd have to say he's all wet.

probably meant in a more narrow technical sense

It may be "oxidized" as in the opposite to "reduced". See also http://en.wikipedia.org/wiki/Redox [wikipedia.org]

(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.)

not exactly :)

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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From TFA

The engine does not require oxygen or a continuous fuel supply, only heat.

This might just mean that oxygen is not consumed, while it could also mean the system contains no oxygen.
But also...

On the high-pressure side of the MEA, hydrogen gas is oxi

Re:

It's equivalent, but more precise -- something that you might want and expect in a nuclear engineer. Some atoms oxidize to form ions, and others reduce to form ions. He's just specifying the particular direction.

Re:Not sure about this...

My snake oil sensors are going off. To be blunt, I don't believe. Theoretical Carnot cycle limits on efficiency due to temperature differences (such as human body to air) are very low. This is what limited the ocean thermal energy systems, as the efficiencies were low and the amounts of matter you had to move past your heat exchanger were very large. The 60% number came from a high concentrator temperature. The reason we don't get such efficiencies with our power plants is material imitations, similar limitations will limit other approaches as well. We are going to have sizable energy losses going through the membranes and be very susceptible to cracking, pitting, and holes. Note that high temperature hydrogen is a rather chemically active environment. Current thermoelectric elements are not yet efficient enough to compete with closed cycle refrigeration systems. Why should I believe that he has a system that can get ~ 50% more efficiency than we can in highly optimized power plants? Note, reasonable increases in efficiency will be very valuable and are worth funding, but the spinmeister publicity is counter productive. Incidentally, I did my Ph.D in solid state thermodynamics some 25 years ago.

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He claims that this is equivalent to the Carnot cycle...specifically it is an Ericsson cycle. It still has the same (low) fundamental efficiency for small temperature differences. This is unlike a fuel cell which is not a heat engine and the Carnot limit

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If you right-click on the animation and choose "zoom in", you can make out the blobs as being H(sub)2 (hydrogen gas) when floating between green areas and H+ (positive hydrogen ions) in the green areas. The description below is pretty good at getting acros

Nuclear Super Soakers..

The man who invented the Super Soaker water gun turns out to be a nuclear engineer

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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... clearly he's better qualified to invent nuclear powered Super Soakers.

...and to put them in the hands of sexy women wearing only t-shirts and panties! Ah, Super Soaker, you rival x-ray vision in your powers of revealing and fun.

The same guy who invented the Super Soaker?

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.

Re:The same guy who invented the Super Soaker?

And, also like Super Soakers, this will spend all its time outside in the sun, and the colors will thankfully fade -but only on one side.

Anyone spot the danger?

This is probably going to dent my karma, but what the heck:

JTEC could potentially harvest waste heat from internal combustion engines and combustion turbines, perhaps even the human body.

With this we can find all the power we need, the plan is to harvest humans, makes the Matrix look almost almost prophetic :)

How about the waste heat from my CPU/GPU?

I want to know more about the principle on which these work, but if they work and can me made inexpensively, they will be found absolutely everywhere where there is waste heat. Couldn't the go under photovoltaic cells - since they convert heat and not light, they could just use the temperature differential between the hot black cells and the surroundings?

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First thing I thought of, what with that article about $1/watt solar cells from a week or so back. CPU/GPU wouldn't be that great a source, I shouldn't think; best you could hope for is a slight offset of the power consumed. However, if they have a decen

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R-value is a measure of the speed of heat flow right?
Insulation works by slowing the heat down enough that at some point the temperture reverses and so does the heat flow.

So if they turn heat into Elec, that then gets used in the house, and generating wast

Another misleading summary

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...

What about Carnot Efficiency?

I hope that it was an under-educated writer talking about harvesting waste human-body heat, and not the NSF or the inventor.

Harvesting waste heat from a 98-degree human operating in even a 30 degree environment is only 13% efficient, at maximum. I just don't see it being real useful to try and harvest waste heat from an ICE or turbine. If a power-plant turbine had useful exhaust steam, they would already be using it to turn another turbine I expect.

The fact it has no moving parts is nice, but how high could the efficiency possibly go?

SirWired

Energy consumption is social justice

Because I am a liberal who is concerned about social justice, I get excited by technologies that could be used to increase energy consumption by folks who are lower on the socio-economic ladder. Increased use of energy consumption for things like refrigeration, home heating, and personal car transportation is something I don't think should be reserved for the upper classes. Inventions that lower the cost of personal energy consumption are worthy of attention and disproportionate investment from fair minded progressives.

Leapfrogging!

It's a popular concept in some circles: [worldchanging.com] 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.

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I'm not talking about the US. Have you ever traveled to a country with a low standard of living?

First?

the first U.S. thermal power plant just getting into production

Way to mis-quote. According to TFA, that's the first solar thermal MANUFACTURING plant... As in, they make the equipment. There are several U.S. solar thermal power plants, dating back to the 70s.

This will be of bigger uses elsewhere

In particular, with nuclear power plants AND geo-thermal. Our power plants dump loads of energy to the environment. This may possibly help with using more of that energy.

Perhaps more important would be geo-thermal. It does not say what the temp differences need to be, but if it can work on ~ 100 degree difference, then this is the answer for the large number of dried up oil wells that have loads of heat down there. The big problem for USA is that we have a large number of wells where the max temp is ~170F. We could hook up a solar heater to carry it up in temp, but if this works, then it will enable these old wells to be re-used and new ones to be drilled.

It's like geothermal... but different...

It uses a temperature differential to produce energy but in this case the differential is created by solar energy heating one end rather than burying one end in the earth and the energy seems to be converted directly into electricity rather than steam to turn a turbine to create electricity. Clever, if it works.

Where is the Hydrogen Coming From?

TFA Talks about pressurized hydrogen gas being diffused across a membrane(s) but it does not mention where the hydrogen gas is coming from. Now, I am NOT a physicist, but unless he has found a new and low cost way to obtain free hydrogen H2 gas then I doubt that his engine will be a substantial improvement over existing technologies since hydrogen gas is generally very energy intensive to separate from water or other reactions. Another problem is that hydrogen gas, particularly hydrogen gas under pressure, is extremely corrosive. It tends to want to diffuse through or undermine the integrity of any material that you attempt to contain it with. This is the reason why hydrogen gas, even though it is the most efficient known working fluid for Stirling Engines [wikipedia.org] is typically not used (Helium or Nitrogen is generally used instead or even just plain air). The difficulty and expense of separating and then containing the hydrogen gas within the engine is just not worth the trouble for the modest gain in efficiency over alternative working gases in Stirling engines. Perhaps someone with more background in physics can explain how the engine in TFA is different and solves these problems?

You cycle it

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.

Patent 7,160,639

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).

oozinator anyone?

May his efforts be more wholesome than the supersoaker oozinator [youtube.com]. Cuz that's just wrong.

Peer review at NSF - Too all with BS alarms

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.

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On the other hand, there aren't many solar processes that really qualify as "efficient" so he doesn't have to work all that hard to double them.

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Well, evidently you're not American or you'd understand where I'm coming from, and in any event you've succeeded in demonstrating the validity of my comment.

Wherever you're from, I hope it's raining.

Re:Hmmm....

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 [wikipedia.org].

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*

Re:Hmmm....

well your bs detector was good to be at high alert.

Currently he has a working prototype that operates at 200 degrees centigrade. the theory implies that at 600 degrees it would achieve 60% efficiencies, existing solar (parabolic mirror based solar electric plants) operate at 800 degrees. since he has a system that works at 200 centigrade, it is not a massive power plant sized unit, that would need to be stable and still work in the 600-800 degree range. if his invention only works at 200 degrees centigrade, then it will never replace convention solar power models. but there are still many potential uses for a 200 degree centigrade model, such as using 'waste heat' from existing power plants to create 'more electricity' with less fuel.

so yeah, i wouldn't hold my breath on this 'still working' at 600 degrees when the guy who invented it hasn't gotten to those temperatures yet.

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The larger the temperature difference, the more efficient a theoretically 'perfect' plant can be. This is also true for real world plants, though engineering limits often restrict how high of a temperature they can sustain and use.

Different technologies a

Re:And...

I can guarantee that the water wasted from super soakers is nowhere near the amount wasted by poorly aimed sprinklers watering cement.

Re:And...

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.

Re:And...

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.

I present to you Seattle, WA.

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What a naive comment.

I live in Melbourne, the 2nd largest city in Australia. Australia has incredibly low population density, yet where the number one issue on everyone - including the everyday mums and dads - is water.
For the last 3-4+ years we've b

I didn't know that

Most energy loss in an ICE is from Air Compression and valvetrain loss?

I would think that most of it would be because combustion is a woefully inefficient way of raising air pressure. Air compression should not be causing too much loss because that energy

Re:Second Law of Thermodynamics

By that logic geothermal power plants wouldn't exist.

Re:Second Law of Thermodynamics

Huh? Recycling waste heat from a internal combustion engine? That sounds like someone is trying to violate the Kevin-Planck statement of the second law of thermodynamics!

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 [wikipedia.org]. Apparently it's not quite possible to reach it, but you're not violating thermodynamics if you're below it.

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After all, are you going to tell me you can't use waste heat from the ICE to heat up some water?

Generally the waste heat from ice I use cools the water. Im interested in this use of ice to heat it up though ;)

srry, just had to do it

Tm

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Waste heat from an ICE might be easier to tap if you used a low pressure (as in near-vacuum) closed cycle medium. Easier to build steam from liquid in near-vacuum, and easier to liquify with an ambient heat sink.

The Kalina cycle [wikipedia.org] engine uses an ammonia+wa

Re:Second Law of Thermodynamics

The majority of wasted energy in an internal combustion engine is in the exhaust gas and in the coolant, which is continuously pumped to a radiator. In a conventional gasoline engine about 1/3 of the energy content of the fuel goes out the exhaust pipe, 1/3 gets radiated by the radiator, and only 1/3 actually ends up doing work on the input shaft of the transmission...

This is why turbochargers are often used on high performance engines - it extracts extra energy from the exhaust flow and thereby raises the thermodynamic efficiency of the whole package. Typical exhaust gas temperatures (at the exhaust manifold) are on the order of 1500 degrees F, which is hot enough to do lots of work.

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From TFA (the popSci URL that does explain it):

Here's how it works: One MEA stack is coupled to a high- temperature heat source (such as solar heat concentrated by mirrors), and the other to a low-temperature heat sink (ambient air). The low-temperature stack acts as the compressor stage while the high-temperature stack functions as the power stage. Once the cycle is started by the electrical jolt, the resulting pressure differential produces voltage across each of the MEA stacks. The higher voltage at the high-temperature stack forces the low-temperature stack to pump hydrogen from low pressure to high pressure, maintaining the pressure differential. Meanwhile hydrogen passing through the high-temperature stack generates power.

IOW, you still need a constant heat source. TFA mentions that they're working on a 200 degree C version, and managed to get their prototype going w/ 60% efficiency if the temp is at 600 degrees C... TFA al

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Ohh yeah, a guy that can hook up an air pump to a water reservoir, he's WELL QUALIFIED to beat the laws of thermodynamics.

Errr... the guy has degrees in mechanical and nuclear engineering and has worked for ORNL and JPL. In fact, some of his work has be

Re:sterling engine?

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.

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Your math is slightly off. Carnot's theorem [wikipedia.org] gives the max efficiency as (Th - Tc) / (Th), or (200 / 473) = 42%. That is, the fraction of the energy you can remove is exactly equal to the fraction of the temperature you can remove. Plugging in 873 for Th

Re:Carnot Efficiency is for Carnot Engine!

Carnot Efficiency is only a limit on a Carnot Cycle Engine!

Carnot Efficiency is a limit to any mechanism that converts heat to energy. Thus it applies to for example steam engines, internal combustion engines, and solar thermal power. Carnot Efficiency does not apply to for example solar cells (PV), although currently these typically have efficiencies of 20% of less so this new thermal method could still be a big improvement.