...but when the fuel's free and available where you need it, who cares if you can only convert a small percentage of the potential energy into electricity?

I don't think you can dismiss the claim that solar would become more efficient than coal or gas just because they too could use the technology.

There is the key difference that coal and gas require the fuel to be transported to the power station through systems that are relatively labour intensive when you include all the lorries, pipe maintainance, off shore platforms, tankers etc. Also include in this the moving parts and maintance required to keep the furnace maintained, clean, and full of fuel.

Solar on the other hand has the advantage that the fuel (light) has zero transport costs and (presumably) the system purely lies on the light being focused on the solid state device. There may be some moving parts as mirrors and lenses adjust angles, and there is probably some cleaning involved. But I could well believe that these things would be perodic operations as opposed to the continual monitoring needed by a fuel burning station.

I can quite believe that solar power could become much cheaper and efficient that carbon producing methods. Of course the key factor is how efficient the technology is and how big a temperature differential it requires. If it requires the electricity to be produced in a desert and run all the way across Europe to provide wet cloudy Britain with power then the net efficiency is likely to be less

The Popular Science article says "Johnson, a nuclear engineer who holds more than 100 patents, calls his invention the Johnson Thermoelectric Energy Conversion System, ..."

How come the U.S. Patent Office only lists 9 patents for the guy?

Could pave the way for body heat powered tech...

Not to mention the possiblities of low power consumption PCs - the heat my box at home generates would probably generate enough to power a small lightbulb at the very least...

What's a bit depressing, is those that have the oil also have the sunlight (what's the % cloud cover in Saudi?).

OPEC for sunlight anyone.

What I can't see on their site is any mention of how great the temperature differential needs to be to generate at a good efficiency.

As the article points out, almost all serious electricity generation directly uses a heat differential (*), but they rely on a high differential, superheated steam or sodium vs. atmospheric temp.

What would be really good is if this could use a much smaller differential. Imagine roads/roofs with this as a 'layer' between them and the subsurface, where you get power generated on a warm day. If it could work with a differential of just a few degrees, then the possibilities are endless, even in a cold climate there are often differences of several degrees between sea and sky, soil and bedrock.

Solar collecting becomes easier since the biggest problem most solar furnaces seem to face is that they have to be, err, furnaces. Using lots of high-maintenance moving parts to focus the sun to a fixed point so a high temperature difference can be created. Now imagine if they simply had a heat absorbant plate, connected through this to cooler bedrock underneath. All solid state and low maintenance..

Of course, if it's as expensive (environmentally and economically) as solar panels per sq. meter then it would suffer the same fate..

Owen.

(*) In fact even wind/wave power indirectly utilises heat differentials; they help power the weather. As far as I know only solar panels and tidal power are not reliant on some form of heat difference.

And have it power my desk lamp or something

Firstly, this is the second time in recent weeks an idea I had years ago has come to fruition in technology. Not happy about that.

Secondly, assuming this technology is far more efficient than solar, then it stands to reason that the idea of having a car driven by a "solar" engine, working from converting the electromagnetic energy of burning hydrogen/methane/etc, could rear it's head as an option again.

slap one on the side of my boiler flue and I'll have some of that 'waste' heat do me some good while keeping warm.

So essentially it’s an electrochemical external combustion engine? A cross between a Stirling engine and a fuel cell? Very interesting. The ability to combine the high efficiency of a fuel cell with the ability to run reliably on any fuel/heat source of a Stirling would be very valuable. Not the least because it would negate the need for all the expensive scrubbers/filters you need to run a fuel cell on anything other than pure hydrogen.

With a good boiler design, it would give flex-fuel a whole new meaning. Return of the steam car, anyone?

Crumbling digestive biscuits into a yoghurt..... Years later, along came muller, and scuppered my plans

Anyone remember these?

http://news.bbc.co.uk/1/hi/programmes/working_lunch/3231549.stm

Whack one of these on your boiler instead of those old sterling engine and think of the grid power generation possibilities.

Bear in mind that Popular Mechanics (source of the referenced article) treats truth and accuracy about as carefully as the average tabloid.

Go and look at http://www.johnsonems.com/ to see his related ideas (lower temperature systems than JTEC, heat pipes). If the JTEC system is viable it will be immensely useful because its potentially 50% more efficient than the best

steam generation sets and can be added to any thermal system to boost its efficiency by using waste heat.

I'd expect to see these in co-generation plants first. Besides, anyone who invented the Super Soaker probably knows how to get his tech out into the real world.

The only thing that concerns me is: high heat + high pressure hydrogen gas = Hindenburg? As many folks (I can't tell if they're anti-green or just anti-hydrogen) have pointed out hydrogen is just a medium of energy storage. Where do you store the hydrogen when the sun isn't shining? If you keep it in the heat engine, it will slowly leak out.

OK, I'm sure better minds than mine have tackled the hydrogen gas storage/inflammability problem. Maybe combine it with carbon to form methane...the lesser of two evils? Just throwing out random ideas here.

Also, Saudi Arabia may have loads of desert sand to play with, but so do multiple other countries. Nobody has a monopoly on sunlight (unless you're talking about Mr. Burns in the SunBlocker episode of the Simpsons). Also, you aren't going to run out of sunlight in the next 100,000 (give or take 5 million) years or so. I don't think even the non-peak-oil people believe that oil will last forever.

Darn...I was hoping that anti-matter would save/kill us all. I'd better get to the asteroids first.

When I was at Uni 18 years ago, one of our professors was developing solid state thermocouples .

This is some of the later work that looks very similar

http://www.iop.org/EJ/article/0022-3727/32/6/002/jd32006l2.html

Sounds like another Colossus, the americans "inventing" something after it's already been done.

Do a search for stoves and fan, and you will see a small windmill that uses the heat from a wood burning stove to make electricity to turn the blades, thus blowing more heat into the room.

I have one and its neat to watch it run only when it gets hot.

..The world needs it now, whatever your stance.

So unless I've read things terribly wrong, this thing still has to follow the laws of Thermodynamics. Well everything has to, but this seems to be a standard thermal cycle, and thus cannot break Carnot efficiency. That would be 1-Tc/Th (Tc = cold reservoir temperature, Th = hot reservoir, absolute temperatures!), so the temperature differential limits the efficiency, which is why people go to a lot of effort to gain another 10 degrees of operating temperature for turbines by doing all sorts of complex things with materials and fluid dynamics.

As it stands modern heat-based power plants get pretty extremely close to Carnot efficiency, which is around 40%. Unless this device can run at higher temperatures than the turbines, it is guaranteed to be less efficient. And how many membranes can you think of that will last very long at 880K?

I doubt that this sort of thing would be able to help out real power plants, but it might be able to pull some energy out of places where it would otherwise be wasted.

But it wouldn't work on a CPU - it would likely interfer with the thermal conduction enough to cause your cpu to overheat. And it wouldn't work on the flue of any modern furnace, because those things leave only enough heat in the exhaust to convince the stuff to rise up the chimney. Pull much more heat out of that and new air to combust won't get to the fuel, and then all sorts of awful happens. Modern gas heaters run at something like 97% efficiency anyway.

In most cases it'd be cheaper and more effective to replace an inefficent device than attach some sort of energy conversion device to it. Especially since these JTEC things aren't really very possible right now.

And from what I've seen, solar thermal probably is the way to go.

[The article goes on to say that "solar [is] more expensive than burning coal or oil. That will change if Lonnie Johnson’s invention works..."

That's untrue, of course, as coal- or oil-burning generators also convert heat into electricity, with the same sort of low efficiency as solar-thermal does

]

Wow, so they "convert heat into electricity, with the same sort of low efficiency as solar-thermal does". Must be the same then! Do you understand how they do this? Solar and fuel burning generators are two entirely different beasts, and other than the fact they both produce electricity have no similarities.

There's no point retrofitting fuel burning stations with JTEC. That would be silly. One it's expensive to rip out the turnbines, generators and excitors etc, and secondly steam powered generators need super heated steam for safety reasons* which seems a bit of a waste in a JTEC system.

You could of course bolt JTEC onto the end of the LP stage, harvesting some more of the heat from the spent steam before you shove it through the cooling towers. That's where the massive efficiency losses lie in fuel burning plants so there are gains to be made there. You then have the problem of either matching the JTEC output to your steam generator, or building another national grid interface for it which won't come cheap.

Or, you could build new fuel burning stations specifically designed to drive JTEC generators.

Trouble is you also have the issue with the fact that FOSSIL FUELS ARE EXTREMELY FINITE.

Ergo substantially improving the viability of solar energy is a good thing and we should be very happy.

In the efficiency maths you should also remember that fuel burning generators are a bitch to get up to speed from cold, so unless you intend to take a generator off line for maintenance etc you need to keep them running (not at full bore mind) so they still use fuel even when the grid says "no ta, we're just taking the nukes power at the mo". Who cares if we're using up some extra sun light compared to coal? There's a few billion years more of that to come - you reckon coal's gonna last another 50?

* condensed water in a steam turbine is very, very bad news. The water droplets are like bullets and strip turbine blades like a farmer strips ears of corn. Then you have 2 issues - firstly white hot, razor sharp turbine blades flying out at random angles and great speed, and secondly, an unstable turbine weighing ~500 tonnes rotating at 3000 RPM. They balance them carefully for a reason you know.

The JOHNSON Thermoelectric Energy Conversation? I call shenanigans on that rather rude-sounding device!

I take anything in Popluar Mechanics or Popular Science with a grain of salt. Those magazines are mostly trash and don't readily vet their sources. They're always showing the next greatest amazing thing that never ever materializes.

If I see it in the Economist or Scientific American or similar publication, maybe I'll take it seriously.

They're tabloids, I tells ya....

Actually, it would be possible to make a Sterling cycle engine with no moving parts driving a pizeo crystal (something real close runs on a few space probes)

_The roads must roll_ was my first thought.

(and now, maybe, they will)

Economist maybe, but Scientific American has been down at the level of Omni for years now. Next you'll be saying Tufte could take lessons from Wired. :-)

and finally paris hilton has a chance to give something back to the world...

The secret is temperature variation, is it?

Well, that's the secret to the world's weather, too, so if temperature variation is good enough to create the world's weather (among other things), then I say it ought to at least have the opportunity to be used for whatever this inventor wants to use it for.

But hey, that's just my opium, uh, opinion.

A few years ago, I saw a semiconductor device that could be used as a heatsink for CPUs and the like. You apply a voltage to it and one side gets hot and the other gets cold. Also, keeping a temperature differential between both sides could generate electricity. The device was called a "Peltier Cooler".

Some websites have been predicting that Thermoelectric Generators will be the next big thing, putting all that waste heat from air conditioners and engines to good use.

One report from 2005 (search for "Free Power for Cars") suggests using the waste heat from a car's exhaust to help recharge its battery. It goes on to suggest replacing the car's engine with a device that turns the heat from the burning diesel/petrol fuel directly into electricity to turn the wheels.

Wouldn't it be great to be able to recharge your iPhone just by holding it under your armpit for a few hours....

The problem with using body heat, or waste heat from your PC etc is that any heat engine causes thermal resistance. This makes makes your body (or PCs) cooling path less efficient meaning that your body/PC will have to output at a higher temperture, or need a bigger fan etc, to get the same power dissipation.

http://www.theonion.com/2056-06-22/news/6/

I'm worried too, Matthew.

Yet another example of El Reg editorialising for the sake of a provocative subheader (hey, I like the *funny* subheaders).

As others have pointed out, this potential development is far from putting the kibosh on alternative energy generation sources. If you hadn't noticed, coal and oil both cost money as raw materials, and then there is the transportation cost. The raw material and transport costs for solar are zero.

Sure, retrofitting old-style generators is bound to be one of the outcomes if it comes to market, but building new power generators using old-style raw materials is going to be a heck of a lot less justifiable in terms of overall costs.

[Added Paris, since I'm sure the subheader is at about her level of comprehension]

You could mount the heat convertor on the back of a solar voltaic panel, provided it actually works of course.

And I'd agree.

I've seen engines that work on similar principles before. Is this guy the first to patent it? Maybe it's using some sorrt of novel membrane? Or this is more patent madness?

There's an engine (i forget it's name) which uses cycles in much the same way as this and was invented at least decades ago. I wish I could remember what it's called.

Here's a magazine article from 2 years ago that profiles some photovoltaic systems that were being combined with thermal energy capture (joint Japanese and Chinese collaboration). Mind you, not much seems to have happened since then....

http://www.enf.cn/magazine/issue4/hybrid.html

Remember folks: So far it's still just vaporware.

They could use this in a lot of hotels, with the heat from the radiators in the rooms (which can't be turned down) powering the air conditioning you have to use to get a comfortable temperature.

Is this what passes for journalism in the reg these days ?

It's becoming little more than an RSS feed for whatever websites the author happens to subscribe to. It's bad enough getting new scientist stories a day light. But popular mechanics ?

Oh - and just the slightest hint of the writer's personal bias completes the picture; "orthodox greens" indeed.

What's up with Black Light Power (http://www.blacklightpower.com/) and its claim to a new process for generating heat for heating and electric power generation?

I agree that Scientific American isn't what it used to be 10 years ago or so, but it's still better than Omni, IMHO. They still go pretty in depth on a lot of articles, though they can be superficial at times, and have gotten more populist with the current editor.

I hate Wired...