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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.'"
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?
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 can be largely recovered on the power stroke. (except for ring blow-by (minimal) and compression-related-heat soaking into the cyl. wall) Valvetrain loss should only be due to cam friction (which is reduced by oil), as the energy required to compress the valve springs should be mostly returned when the valves are released.
SirWired
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
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.
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.
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 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?
I'm really waiting for the nanotech implementation of these heat engines. The nanoscale mechanics will be higher efficiency, and embedded as materials into PV materials, will seem to be simply high-efficiency solar panels, not complex machines. Maybe more than 70% efficient. And I expect they'll be lower-energy to manufacture with chemical processes, rather than mechanical assembly, and last longer, so their overall lifetime efficiency will be several times greater than today's.
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make install -not war
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.
According to the diagram on the website, it seems that the low temperature stack is receiving electricity to "pump" the proton through the barrier and loose energy to heat dissipated.
On the hot side, heat is absorbed and electricity is produced.
Why would the electricity output be greater than the input.
Also, in a fuel cell, one chemical reaction is Hydrogen => Proton + Electron, the other side of the barrier is Proton + Oxygen + Electrons => Water.
How come this engine can regenerate Hydrogen on the other side of the barrier while the Fuel Cell has to use Oxygen to produce waste water ?
The Kalina cycle engine uses an ammonia+water mixture as its working fluid for that reason. Also, the reference in that article claims the mixture boils at a range of temperatures instead of at a specific point, but does not say why.
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.
> well your bs detector was good to be at high alert.
:)
[snip]
> 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.
How negative can you get?
This is not "fusion in a jam jar"; unlike that debacle, this guy's homepage explains the process in terms of well-understood theory. I haven't done any engineering thermodynamics since university, but it sounds believeable. No pretty cycle diagrams to help me, though; experts may say different.
Peer review pending, Mr Johnson seems to have discovered a phenomenon that harnesses known laws of physics in a new way, i.e. this is new *science*. Thermodynamic theory says that the the potential efficiency can only increase with temperature, so expanding the operating envelope (e.g. raising/lowering the temperature limits) is probably a "simple" matter of development, new materials, etc; i.e. technology, and time.
The potential to reclaim waste heat has enormous implications; but even where JTECs can't compete on efficiency, other factors such as low-zero maintenance and reduced costs could make this a desirable technology. For example, elimination of steam turbines would make even classic power generation cheaper, while simultaneously increasing the safety of nuclear power specifically. Nuclear fusion immediately becomes more viable, too.
Another beauty of this system is that it's viral - its introduction can be staggered, maximising the efficiency and useful life of existing capital investment. No need to replace your local power station, just stick a JTEC on the waste heat output line...and refit those ugly cooling towers for alternative duty, e.g. a warehouse (or simply sell off the real estate!).
JTECs could revolutionise space exploration, too; the extremely sharp differential between heat/cold outside our atmosphere is an environment that's ideal for any kind of heat pump. Increase the amount of power available to a space mission and you increase its capability proportionally. Moonbase Alpha, anyone?
Make no mistake; the possibilities of this are HUGE, much bigger than implied in TFA.
C