Author Topic: Energy From Sun  (Read 5634 times)

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Offline McDonough

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Energy From Sun
« on: May 25, 2009, 11:02:46 pm »
The energy from Sun can empower the whole world for a long period of time. The usage of solar energy produces no pollution and is therefore environment friendly. Sun’s energy can be tapped by collecting its heat or by collecting its light and converting it into electricity. The sun’s radiation can be converted into electricity by using the solar power plants or photovoltaic devices, also known as Solar Cells.

In solar power plant, mirrors are used to reflect the heat energy from a large area onto a small space, such as a pipe filled with a fluid. As the fluid's temperature gets raised to hundreds of degrees, it is used to boil water and produce steam for a conventional generator. PV or Solar cells, on the other hand, change sunlight directly into electricity. A PV cell is a non-mechanical device usually made from silicon alloys that absorb photons emitted from the sun. The photons hit the silicon atoms in the PV cells, transferring their energy and releasing the electrons from their orbit around the nucleus, thereby generating electricity.

The promise shown by the solar energy technology has made investments into solar sector, worthwhile. It is a growing industry with increasing demand and better production capability. All this indicate that it is wise to make solar power investments.

Offline Jackson Holly

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Re: Energy From Sun
« Reply #1 on: May 25, 2009, 11:30:05 pm »

Converting CO2 to fuel



http://www.youtube.com/watch?v=GJ5mpQqmZaM&feature=related

Wow! Check out this short video ... petroleum created from CO2 and H2O, with sunlight as an energy source.

These guys are from out here in New Mexico, my location ... the guy in the ponytail is Rich Diver, a friend of a friend.

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Let it loose; it will defend itself.-

Offline freeflying

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Re: Energy From Sun
« Reply #2 on: May 26, 2009, 06:25:18 pm »
I did a huge photo project that included solar energy. Through talking to all the experts that make the panels and install them it became clear that we will never be free of fossil fuel power as the amount of panels and storage needed would bankrupt the world. Panels also don't last much beyond 20 years which is the point which they have paid for themselves.

I did a interview with a company last year that created a new type of panel that cost 1/4 of conventional panels and lasted longer and the government got involved and will not allow them to build the panels. I believe they are closed now after the owner invested his life saving into it only to be denied by the government.

Offline Jackson Holly

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Re: Energy From Sun
« Reply #3 on: May 26, 2009, 10:13:11 pm »
freeflying


Quote
I did a interview with a company last year that created a new type of panel that cost 1/4 of conventional panels and lasted longer and the government got involved and will not allow them to build the panels. I believe they are closed now after the owner invested his life saving into it only to be denied by the government.


THAT is big news! Do you have a link on that case?

But I am not surprised ... TPTB making truly advanced, nearly-free energy tech TABOO, to protect their cash cow industry.

Reminds me of the discussion we are having here about magnetic motors:


http://forum.prisonplanet.com/index.php?topic=97516.0

St. Augustine: -The truth is like a lion; you don't have to defend it.
Let it loose; it will defend itself.-

Offline freeflying

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Re: Energy From Sun
« Reply #4 on: May 27, 2009, 01:32:37 am »
freeflying



THAT is big news! Do you have a link on that case?

But I am not surprised ... TPTB making truly advanced, nearly-free energy tech TABOO, to protect their cash cow industry.

Reminds me of the discussion we are having here about magnetic motors:


http://forum.prisonplanet.com/index.php?topic=97516.0



Not going to get into it because I have been told not to but the panels are so simple it is stupid. There was one reference to them a couple years ago and myself and a writer did a story on them and it got buried. There is no mention of the company anywhere period and they seem to have been erased completely from the web. I ordered a copy of the program I saw them on that started the story idea and it was edited out. It is so simple it is a coating on glass plates of a material that creates electricity from the sun or any light source. Even the patent is gone it is so far ahead of the other panels. The most expensive part was the glass panels. There were no cells that were soldered together like conventional panels, just a coating and a pair of leads. They want this shit so expensive that nobody will be able to afford it.

I left something on the magnetic motors thread as well. That will never come out either and it works well and is self sustaining and the only maintenance is bearings and brushes but I know of one that was brushless.

Offline fred.greek

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Re: Energy From Sun
« Reply #5 on: May 28, 2009, 12:19:12 am »
THE SOLAR ENERGY LIMIT

Our readily available source of sustainable energy is solar.  There is logically a maximum amount of solar energy that would be available to an Earthbound human society.  Imagine we covered the entire surface of the Earth with solar panels (think Trantor in Asimov's stories, or Courasant (spelling) in Star Wars).

Every square yard of the surface of the Earth exposed perpendicular to full sun receives around 1kw of energy.  A square mile contains roughly 3 million square yards.  Using 10% efficient panels is represents AT BEST 300 megawatt of generation.

The Earth presents an 8,000 mile diameter disk to the sun.  But remember, the world is not flat, is tilted relative to its orbit, and rotates.  The further you are from the equator, the less sunlight per square meter of surface, therefore covering polar regions with solar panels would be impractical.   To provide continued collection in the non-polar regions, the entire earth would need to be belted with panels.  At any given moment though, probably a circle of 5,000 mile diameter or less would face the sun adequately for solar collection.  Area = Pi x radius squared.  With present solar panels (say 10% efficient), how much power could we intercept?

It's an area of 19,634,954 square miles exposed to the sun.  It is 60,821,233,704,000 square yards, each intercepting, when not shaded by clouds, an average of something under 1 kilowatt.  (For design/building purposes, remember the curve of the Earth.  To expose a 5,000 wide area probably requires 7,500 mile wide be covered on the surface of the Earth.)

Assume half are shaded by clouds at any given time, so it's intercepting something under 30,410,616,852,000 kw.  Readily available p/v panels are around 10% efficient, so we could expect to have 30,410,616,852 kw.

Let's compare the energy to our oil use.

Recent annual oil use was 30 billion barrels, or 126 billion gallons.

A gallon of fuel has 144,000 BTU, equal to around 36.7 kwh.

If we use the array and the electrolysis process to obtain hydrogen from water, the best efficiency rate discussed is 50%, or that we must put in twice as much power as we gain back when we use the fuel.

Every hour the array operates is could produce hydrogen fuel equal in BTU's to around 414,313,581 gallons.

Operating 24 hours a day, say for 360 days a year on the average, it could produce 3,579,669,339,840 gallons. 

The good news is that such a global solar array could provide electrical energy and convert it to hydrogen fuel roughly equal to 28 times our recent annual oil use. 

Remember though, the bad news is that the surface of the planet is covered with solar panels, with essentially no open exposure to the sky, on land or on the sea.   And of course, there's all the silicon for the panels, wire, metal, etc., exponentially beyond any supply of such materials we dream may be available to us.  As touched on in an earlier comment on China and  copper demand, there is probably not enough copper left to mine on Earth for this type of project.

To replace "just" our recent 30 billion barrels per year is an array constantly in the sun of 701,248 square miles.  To have a five thousand mile wide swatch of constant sun at the equator equal this area, we would need a solid band of photovoltaic cells around the earth at least 140 miles wide, across oceans, mountains, etc. 

The "real world" power per facility footprint is of course NOT as good as the above.  In 2005 Stirling Energy Systems started planning on a solar thermal generating facility for the desert in southern California. 

The facility, to generate 500 megawatt, will have a footprint of 6.25 square miles.  (Roughly 19 million square yards.)  This planned facility tops-out at 80 megawatt per square mile, vs the 300 of theoretical top using 10% panels.  In a quick estimate, to expand this real-world facility to be large enough to replace our annual oil use would require a continuous band built around the equator of the Earth around 540 miles wide.
Retired but still working in the garden...

Offline Jackson Holly

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Re: Energy From Sun
« Reply #6 on: May 28, 2009, 07:53:17 am »
Looks like we need to increase that sorry 10% efficiency rate ...

and new/cheaper collection methods as described by freeflying ..

and ways to cut demand ...

and combined with other alternative sources ... and magnetic motors / etc ...

maybe we might be able to continue an advanced society when the day comes when

extracting oil and burning it is no longer feasible.




St. Augustine: -The truth is like a lion; you don't have to defend it.
Let it loose; it will defend itself.-

Offline Mr.Me

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Re: Energy From Sun
« Reply #7 on: June 04, 2009, 05:37:16 pm »
http://en.wikipedia.org/wiki/Solar_chimney

Works better than PV cells, as overnight the ground gives up it's heat.

I've only seen one video of it, of which I can't remember the name, but heat exchangers for me sound the most reliable form of solar energy.

You extra heat, say from the sea, and use that heat to generate steam to turn turbines. It always works, as long as the thing you're extrating heat from (the ocean) remains above the freezing temperature of your refridgerant, which could be as low tech as ethanol.