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A Solar Power Breakthrough....

Posted: Mon Oct 18, 2010 1:48 pm
by sirwilliam
A Solar Power Breakthrough, Courtesy of the Guy Who Invented the Super Soaker

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Lonnie Johnson did risk assessment for the Atlantis space shuttle. He helped get the B-2 stealth bomber off the ground. He gave us the Super Soaker. And now, with his latest invention, he might just make solar power viable.

Johnson, a "self-invented inventor," is profiled in the November issue of the Atlantic, and while his Super Soaker revolutionized backyard shenanigans, his latest project, a unique heat engine called the Johnson Thermoelectric Energy Converter or JTEC, could revolutionize the energy industry. And that's got some important people very excited.

Today's run-of-the-mill solar cells convert around 20% of the solar energy they gather into electricity. The best solar systems we have can do about 30%. The JTEC, which has no moving parts and produces no waste, could double that efficiency, making it competitive with coal. Paul Werbos, director of the National Science Foundation, says "It has a darn good chance of being the best thing on Earth."

So how does the JTEC do what it does? A very elegant design and the second law of themodynamics:
Simply put, the law says that temperature differences tend to even out-for instance, when a hot mug of coffee disperses its heat into the cool air of a room. As the heat levels of the mug and the room come into balance, there is a transfer of energy.

Work can be extracted from that transfer. The most common way of doing this is with some form of heat engine...

...Johnson's latest JTEC prototype, which looks like a desktop model for a next-generation moonshine still, features two fuel-cell-like stacks, or chambers, filled with hydrogen gas and connected by steel tubes with round pressure gauges. Where a steam engine uses the heat generated by burning coal to create steam pressure and move mechanical elements, the JTEC uses heat (from the sun, for instance) to expand hydrogen atoms in one stack. The expanding atoms, each made up of a proton and an electron, split apart, and the freed electrons travel through an external circuit as electric current, charging a battery or performing some other useful work. Meanwhile the positively charged protons, also known as ions, squeeze through a specially designed proton-exchange membrane (one of the JTEC elements borrowed from fuel cells) and combine with the electrons on the other side, reconstituting the hydrogen, which is compressed and pumped back into the hot stack. As long as heat is supplied, the cycle continues indefinitely.
Johnson's currently wading through the swamp of bullshit that surrounds the act of inventing—getting research grants, filing patents, trudging through peer review, etc.—but energy experts familiar with the JTEC agree that's definitely something to get excited about. Read more about the JTEC and the man who invented it at the Atlantic.

Re: A Solar Power Breakthrough....

Posted: Mon Oct 18, 2010 4:10 pm
by Sabre
Wow, great to see some alternatives to the usual ideas! This seems pretty viable and not too expensive to build. I do wonder how well larger prototypes will scale though.

Re: A Solar Power Breakthrough....

Posted: Mon Oct 18, 2010 9:26 pm
by complacent
Sabre wrote:Wow, great to see some alternatives to the usual ideas! This seems pretty viable and not too expensive to build. I do wonder how well larger prototypes will scale though.
what he said plus :popcorn:

Re: A Solar Power Breakthrough....

Posted: Mon Oct 18, 2010 10:10 pm
by Mr Kleen
if we can harness solar power on a large scale, very very cool things will be possible.

:popcorn:

Re: A Solar Power Breakthrough....

Posted: Tue Oct 19, 2010 8:24 am
by sirwilliam
Mr Kleen wrote:if we can harness solar power on a large scale, very very cool things will be possible.
This.

When I think of solar power, I always think of Pitch Black, though... :lol:

Re: A Solar Power Breakthrough....

Posted: Tue Oct 19, 2010 9:19 am
by Cereb Daithi
JTEC just kicked in, yo.

Re: A Solar Power Breakthrough....

Posted: Tue Oct 19, 2010 10:14 am
by Sabre
Cereb Daithi wrote:JTEC just kicked in, yo.
:rolllaugh:

Re: A Solar Power Breakthrough....

Posted: Wed Oct 20, 2010 8:47 am
by TRANS4M
Cereb Daithi wrote:JTEC just kicked in, yo.
This came to mind.

Re: A Solar Power Breakthrough....

Posted: Wed Oct 20, 2010 9:15 am
by Cereb Daithi
I couldn't resist. In all honesty though this really is cool stuff though. Major kudos to someone that can invent both iconic toys and apparently make significant scientific progress.

Re: A Solar Power Breakthrough....

Posted: Wed Oct 20, 2010 1:58 pm
by drwrx
I still see some of the problems that are present with existing solar power. How large a unit would it require to heat a home in winter or cool a home in summer? If it takes the entire area of your roof to capture the rays required, and a heat engine the size of a small shed, with an up-front cost of $10k+ there will not be a lot of takers. And that is on the small scale. If you plan on building solar farms hundreds of miles away from your users with the current level of loss it still won't be economical.

I'm actually an advocate for this sort of "green" energy and I don't want to be a come off as a nay-sayer, but I still have my doubts.

Re: A Solar Power Breakthrough....

Posted: Thu Oct 21, 2010 2:30 am
by zaxrex
You and me both.
Just for fun, I took the little information available in the article and did some crunching. Here is what I found.

For calculation purposes, we will assume 22 L of H (which is pretty funny since almost all of our hydrogen we can get our hands on is H2, which ionizes more easily, but does not leave a simple individual proton as a result of ionization per the article).

As we all know :rolllaugh: it takes about 1300 kilo Joules to ionize that amount of hydrogen into free electrons and protons. Not only that, but we have to get to 1 Mbar (that is mega bar) in pressure and 1700 deg. F in temp. Not something that simple pipes and gauges are able to withstand.

I would like to know how that temperature and pressure is generated by the 700-1000 W/m^2 solar incident energy. That is one hell of a solar collector. Tow a basketball court sized solar array with you for your JTEC?

I need more data.

Re: A Solar Power Breakthrough....

Posted: Fri Oct 22, 2010 9:13 am
by Sabre
You and your scientific approach.... :rolllaugh: