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Thread: Does solar power have a future?

  1. #1 Does sollar power have a future? 
    Forum Isotope (In)Sanity's Avatar
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    I forget what percentage of efficiency we are up to now on solar (photovoltaic) cells, I think it's around 35-38% or so. It may be higher by now I'm not 100% sure. Has anyone done any research into this area and if so do you see that solar electric power has a future, or will it always be kind of niche market?


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    I think it's going to be in a niche. Be a niche? I'm not sure how to say that. But yes, it will only be used where it can be used and will always need a backup source should the sun be blocked by clouds, etc. However, if you harnessed it by building something that could collect it above all clouds.. I really don't know enough about it. Either way you look at it, you get power half the time and no power half the time because of the earth's rotation.


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    I think if we spend more money on solar, we could improve it's efficiency. i mean c'mon all life is possible because of the sun, you mean to tell me we can't warm a friggin' house from it?
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  5. #4  
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    http://en.wikipedia.org/wiki/Solar_cell#Yield_data :

    The best efficiency of a bare solar cell as of April 2003 was 16.5% [Dr IM Dharmadasa, Sheffield Hallam University, UK]. Higher efficiencies (around 30%) can be obtained by using optics to concentrate the incident light.
    This is in reference to a silicon cell (monocrystaline I think) other types of silicon cells exist that are less efficient but cheaper. So called “thin film” technologies exist that are much cheaper but also less efficient. The early commercial thin film technologies suffered from a loss of efficiency as the photovolteics (PVs) aged. This has soured the market towards them somewhat. Thin film producers claim to have corrected the problems but the market has yet to rewarm to them.

    IIRC current comercial silicon PVs are about 10-15% efficient and thin film PVs are around 5-6% efficient.

    Electricity will have to become 2-3X more expensive for the PV market to take off unless government subsidies (probubly in the form of consumer tax credits) increase. Most of the electricity in the US is generated from coal and natural gas. Coal is expected to remain cheap for the foreseeable future. Although there is still lots of natural gas in the world, we are quickly burning through North America’s resources. It is quite likely that the price of natural gas could increase significantly in North America in a few years, as liquifying it and shipping it are not very energy efficient and will significantly add to its price.

    I think PVs will remain a niche market for the next 5-10 years, but as more evidence of global climate change accumulates, intrest will increase. Of course a lot of this depends upon the attitude of our government.
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  6. #5  
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    Hmm, I was way off. Kind of wish I wasn't. I know they talked about placing a collector in space and using microwaves to transfer the energy down the earth. Would be great unless your a bird
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    Sometimes I’m way off too.

    I read a book recently (I would sight it but I do not have it at hand) that reviewed the possibility of putting geosynchronous PV satellites in orbit. They would send the energy to earth in safe microwaves. Another plan was to build solar collectors on the moon to do the same. They concluded in all seriousness that it would be possible to do safely (even for birds) with today’s technology, but it would take more energy to launch all of the equipment into space than would be generated during the life of the satellites.
    Terrapin
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    Hmmm.. Why put a collector in space when you can put a nuclear power station in space and beam the energy from that down? You have to admit, in case of a nuclear meltdown, it would be a lot safer tossing it into outer space than into an urban area.

    I might be wrong, but would such a collector be money-efficient. Personally, I would much rather invest time and money in way to use cold fusion...

    Mr U
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    Interesting thought Mr. U. I suppose the answer is political. No one wants to put a reactor so far away where it would be hard to defend. Other countries might not be too happy about having a reactor overhead whose orbit could potentially be redirected to fall on them. And then there is always the international suspicion factor: “How do we know it is only a reactor and not a weapon?”

    Cold fusion, that would be something huh? The problems seem rather daunting (but they also said man would never fly). I think it would be a good topic for another thread.
    Terrapin
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    Quote Originally Posted by Terrapin
    Interesting thought Mr. U. I suppose the answer is political. No one wants to put a reactor so far away where it would be hard to defend. Other countries might not be too happy about having a reactor overhead whose orbit could potentially be redirected to fall on them. And then there is always the international suspicion factor: “How do we know it is only a reactor and not a weapon?”

    Cold fusion, that would be something huh? The problems seem rather daunting (but they also said man would never fly). I think it would be a good topic for another thread.
    Well, I believe the same can be said for other orbital stations. How can you be sure that someone is not creating a "Friggin' Laserbeam". Sure, they can be turned into weapons, but so can Nuclear Power plants. Just shut down the reactor, and you have a big boom-boom. In fact, I would think that knocking a satellite out of orbit would be a lot more challenging to terrorists. Blowing up that security door and killing the security guards in a nuclear power plant seems easier than building and launching a space-shuttle, docking and sending the satellite out orbit, all of the three processes have to be done with incredible mathemetical precision and require highly-trained professionals. Now, it is not my intention to discredit terrorists, but they are, mostly at least, not highly-trained people.

    I am confident that we will eventually find the technical solution to containing and transforming the energy released with cold fusion. It's like not knowing how to properly align the wings to create a drift. Eventually, we will hit the right combo and get the bird into the air. Eventually, who will care about all the plane crashes?

    Mr U
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    Your points are valid Mr U but we both know that laser beams do not have the devastating potential of a nuclear power plant.

    Since:
    1) Human generated satellites have a tendency to sooner or later fall to earth.
    2) The mass of a nuclear power plant would be such that it would survive reentry into our atmosphere.
    3) Toxic nuclear byproducts have half lives measured in hundreds of thousands of years.
    4) It would not necessarily have to be terrorists (as we think of them today) who might bring the station down.
    5) Murphy’s Law states……

    I imagine that you are only continuing to take your side of this discussion for purpose of debate. :wink:
    Terrapin
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    Well, I was not specifically referring to nuclear plants, since Cold fusion plants, when (not if ) they get them to work, will also be able to be put in outer space.

    1) Perfection of satellites. If we are going to rely on Satellites for supporting our communications, these elemental flaws will have to be corrected sooner or later. Whether it is a spy, nuclear or 'solar power beam' -satellite.

    2) So? We can send it for another run! :P If the satellite should go out of orbit, we could detonate it, or we could just let it drop. A shut down generator won't just blow up, not even when it's outer temperature is heated. Hell, we can even put those heat-absorbing tiles on the side just for makin' sure.

    3) More of a general problem of Nuclear plants, and a problem I am well aware of. I hope we can soon switch to Cold fusion, but I would rather breath oxygen and have some concrete on the bottom of the ocean filled with nuclear waste, than choking on CO2, if we use fossil fuels instead.

    4) I agree that 'crackers' could hack into the satellite and bring it down, but they can also hack into a normal nuclear plant. Nations can bring down the satellite, but they can also nuke another nation. It's not like the UN won't see when someone launches a rocket heading into space. Does this make the space station less safe than a ground-based station?

    5) He. My Discordian principles make me disbelief Murphy's Law, so there! :P

    Oh, you have no idea how much I love debate. Besides, it's not like any taxpayer would give their money, well voluntarily at least, for a nuclear space-station, now would they .

    Mr U
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    Mr U-

    It has been a pleasure. I’ll catch you later.
    Terrapin
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    I think a first step would be to install solar heating in as many houses as possible. It can give you 25% of your energy consumtion even up north. If I was building my own house I would absolutly consider it. Better yet, design houses soo they make the most out of the suns energy. Big windows south, thick heat preserving walls. A well design house will heat itself in the winter and cool itself in the summer. If you live in California solar energy must be a a good option at least for a protion of your energy needs. Alternative energy looks best on a local scale I think.
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  15. #14  
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    Now we just need solar Air Conditioning, Living in Phoenix we get about 83-85% sun coverage year round, the problem is the coldest temperature I've seen here in the last 5 years is 33 and that was in the winter time late at night. Heating is not a problem The sun is also much more intense then it is in the northern states, I guess being closer to the equator.

    I do have to agree that solar heat would save a ton of money for those that need heat.
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    Yeah I can see that. How watts does your AC draw on average?
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    Quote Originally Posted by daijo
    Yeah I can see that. How watts does your AC draw on average?
    That I don't know.

    I found a link to the unit, it's only about 3 years old. We have the 36,000 BTU model.

    http://www.trane.com/Residential/Pro...its/XL1400.asp

    Switching to this unit saved us about $150 a month in the summer time and about $50-$60 a month in the winter time when we actually do need a little bit of heat. It's actually cheaper to use this heat pump then it is to just run the pilot light on the old gas heater we have. Needless to say the gas heater is now turned off completely.
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    Wow that's 10.5 kW (quite similar in power to what is needed to heat a home here in winter. So I see your problem trying to run that by solar or wind power.
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    Quote Originally Posted by daijo
    Wow that's 10.5 kW (quite similar in power to what is needed to heat a home here in winter. So I see your problem trying to run that by solar or wind power.
    Wind would be totally out of the question, AZ has very little wind most of the year. I think solar hot water would work really well here. Solar electric appears to be too expensive for the average family to even get a basic setup. Phoenix has a ton of sun and also a lot of lower income imagrants. The people who can afford solar electric often don't bother as they have no shortage of cash. Kind of a backwards problem.
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  20. #19  
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    Hi there:

    Solar energy through PV can help generate hydrogen.

    This would be a huge step forward to getting hydrogen economy going.

    For more information on renewable energy and hydrogen production, check out the following URL: http://www.renewableenergyaccess.com

    Thanks,

    Gordan
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    Hi Gordon

    Welcome, and thanks for reviving an old thread that is near and dear to my heart.

    You are right; PV electricity (or electricity in general) can be used to produce hydrogen. Unfortunately electricity alone is extremely inefficient (some number around 50% comes to mind but I am too lazy to look it up) to use for producing hydrogen. As I understand it, the conversion factor can be increased by about 10% or so if the hydrogen is made from steam rather than water. This is why co-generating hydrogen at nuclear plant sites makes sense. It allows us to put the “waste steam” from the power plant’s cooling system to work.

    However: Hydrogen is extremely inefficient to transport. This is why local disseminated PV or otherwise electrically produced hydrogen makes sense. Unfortunately it would take acres of PV arrays to produce enough hydrogen to keep one moderately busy filling station supplied.

    I have some hope for hydrogen, but the problems that remain are daunting.
    Terrapin
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  22. #21  
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    Quote Originally Posted by Terrapin
    Hi Gordon

    Welcome, and thanks for reviving an old thread that is near and dear to my heart.

    You are right; PV electricity (or electricity in general) can be used to produce hydrogen. Unfortunately electricity alone is extremely inefficient (some number around 50% comes to mind but I am too lazy to look it up) to use for producing hydrogen. As I understand it, the conversion factor can be increased by about 10% or so if the hydrogen is made from steam rather than water. This is why co-generating hydrogen at nuclear plant sites makes sense. It allows us to put the “waste steam” from the power plant’s cooling system to work.

    However: Hydrogen is extremely inefficient to transport. This is why local disseminated PV or otherwise electrically produced hydrogen makes sense. Unfortunately it would take acres of PV arrays to produce enough hydrogen to keep one moderately busy filling station supplied.

    I have some hope for hydrogen, but the problems that remain are daunting.
    I really can't get why someone would ever want to use nuclear energy to produce hydrogen. It si far more efficent to use the electricity to move a electric vehicle!

    Hydrogen is only viable when it drains energy from a low-density source and piles it all the way up to high-density fuel. That is, let's say you have got a low-density energy source, too low density as to try to gather it into high density and be economical. If this source turns to be terribly cheap and abundant, then proficency is not all that a big deal.

    It is not the same to use, say, 10% of terribly costly generated nuclear electricity to manufacture hydrogen, than use a 0.01% of a energy which was a million times cheaper than nuclear energy.

    Now, all what we need are cheap and abundant low-density energy sources, which can be processed locally at minimal cost and specially with minimal usage of energy. Let's say, fermentation depots which turned organical waste into ethanol and methanol. then the alcohols could be distilled with thermal solar energy. This could provide fuel to places with a intensive generation of organic waste -waste dumps and farm lands.

    ITOH, it is unlikely that hydrogen, solar power or whatsoever wille ver supply us the same amount of energy we get from oil. A call for proficency and rationality should complement any "alternative" energy source, at least until we develop nuclear fussion AND find a way to deal with extra heat waste once we start turning water into heat.

    The days of wasting energy just to move from point A to point B are called to end, the same as the days of moving from point A to point B just for sake of not go walking to the shop next corner.

    All that "nuclear hydrogen" story just looks like giving a candy to all that owners of 3 tons monsters with 450 hp engines which do exactly, exactly, the same as 1.5 ton vehicles with 110 hp engines... has anyone calculated how many nuclear plants would be needed to supply the BTUs currently consumed by private vehicles in the USA, fai?
    “If the misery of the poor be caused not by the laws of nature, but by our institutions, great is our sin.” -Charles Darwin
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  23. #22  
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    Quote Originally Posted by Lucifer
    I really can't get why someone would ever want to use nuclear energy to produce hydrogen. It si far more efficent to use the electricity to move a electric vehicle!
    You need some way to store the electricity in the vehicle; a hydrogen/oxygen fuel cell is the best way to go about it. You could argue "Why not just use the electricity from a power plant to charge a battery in the car," but in that case you are usually just performing some analogous chemical process within the battery when you convert the electrical energy to chemical potential energy.

    Also, it should be noted that you can make gasoline from coal, and we have so much coal in the U.S. that we will probably never run out. That's how South Africa got most of their gasoline when the rest of the world had embargoes against them. Supposedly the process is competitive once the price of oil rises above $60/barrel. I believe it's called the Fischer/Trops process (I probably spelled that wrong). It's not popular at the moment because a lot of companies got burned after investing tones of money in plants to make gasoline from coal back during the last energy scare in the 1970s, only to have the price of oil drop too low around the time the plants were supposed to come online. If oil prices ever stay high for a long time with little chance of dropping back down, you can bet that Fischer/Tropps plants will start popping up everywhere.
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    Here are a few numbers to consider:

    In 2003 the mean U.S. electrical power consumption was 4.4E11 watts. The mean solar flux on the surface of the U.S. is around 150 watts/m^2. This means that you would need about 3000 square kilometers of solar panels to provide the average power consumption for the U.S., assuming you could capture 100% of the energy. In reality the best cells only capture around 30% of the total solar flux, so with the best modern technology you would actually need about 10,000 square kilometer. It gets worse; the best solar cells are very expensive, difficult, and slow to fabricate. Solar cells that could actually be mass-produced with current technology only capture around 10-15% of the total solar flux.

    Note that this is just to replace all the electricity used in the U.S. with solar energy. If you want to replace all energy used (like energy produced by burning gasoline in cars, etc.) it gets substantially worse.
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  25. #24  
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    Time to Power Down.
    Terrapin
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  26. #25  
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    Quote Originally Posted by Scifor Refugee
    Quote Originally Posted by Lucifer
    I really can't get why someone would ever want to use nuclear energy to produce hydrogen. It si far more efficent to use the electricity to move a electric vehicle!
    You need some way to store the electricity in the vehicle; a hydrogen/oxygen fuel cell is the best way to go about it. You could argue "Why not just use the electricity from a power plant to charge a battery in the car," but in that case you are usually just performing some analogous chemical process within the battery when you convert the electrical energy to chemical potential energy.
    Well, that's one way to put it; I was thinking about transportation cost. Also there's a "third way" I just reminded: to use compressed air as storage mean. There's some small towns in France that use this technology in cabs, single-handedly developed and built by a french inventor and enterpriser. They have an engine of some 50 hp and a full air depot allows them to make some 300 kilometers. The advantage is that a compressed air engine is just a simplified version of a 2-strokes engine.


    Also, it should be noted that you can make gasoline from coal, and we have so much coal in the U.S. that we will probably never run out.
    Well, liquefaction of coal is a good last resource. Anyway, as far as I remember, it releases a huge heap of CO2, and so it would contribute to CO2 emissions. It also produces huge heaps of scoria and useless ashes; by all means, it is FAR more polluting than oil, and of course, once you're going to paoy the extra buck for fuel.... why not use hydrogen (as long as you don't burn all Uranium depots in the process.)

    (...)If oil prices ever stay high for a long time with little chance of dropping back down, you can bet that Fischer/Tropps plants will start popping up everywhere.
    Let's assume we'll be smarter than that...


    BTW, today I just heard in the News that there is estimated that in order to generate enough energy to make a relevant cut in cO2 emission, there would be needed 1,000 new nuclear plants... which, if ever built, would deplete all Uranium depots in about 20 years.

    I think the mood goes as: "Energy waste no longer can be a consumer product". :wink:
    “If the misery of the poor be caused not by the laws of nature, but by our institutions, great is our sin.” -Charles Darwin
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    Does anyone here now how much just one solar panel costs? A huge amount!! And it also costs big $$ to transfer it to electricity. I don't ever think solar power will take over as the main energy source, even though it is highly practical.
    You may think you're the best at everything, Mr. Anderson, but I am. I am you're opposite, you're better half. You've been a bad boy, Mr. Anderson.........
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  28. #27  
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    The cost of solar panels continues to fall. At some point a combination of improved manufacturing techniques, increases in conventional energy costs, and greater uptake of usage, perhaps complemented by government incentives, will make the cost economic.

    In situ energy production is inherently more efficient, since transmission losses are eliminated.
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  29. #28  
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    Even so, solar power only takes up 1.6 % of the energy that we use... It's going to take a lot of growing to get to at leastt 20%
    You may think you're the best at everything, Mr. Anderson, but I am. I am you're opposite, you're better half. You've been a bad boy, Mr. Anderson.........
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