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Solar energy after the sun sets

I am a new member but I did not see this idea proposed yet. Using a highly efficient air compressor to compress ambient air which also compresses the solar heat which is in turn used to heat a sterling engine. The sterling engine turns the compressor (initially this process will need a jump start) and then the compressed air is used to spin an electric generator. But because the heat has been removed from the compresses air it is used to absorb heat from the other side of the sterling engine thus improving its efficiency. The output would be free electricity and water that fell out of the air when compressed. The energy that powers this process is pure solar so nothing magic is going on. Any thoughts?

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    Mar 20 2013: The amount of solar energy per square metre is approximately 100watts average. It doesn't matter how it is collected or how it is stored. PVs aren't all that efficient (25%) at collection but current storage methods allow 90% recovery.

    The electricity produced by the generator being spun by the compressed air would be equal to the electricity used to power the compressor minus the amount of energy the sterling engine converts into work, minus the efficiency losses in the compressor, the generator and the stirling engine. The energy recovered from the ambient air would be tiny as ambient air isn't very hot or very dense. I doubt that you would be able to harvest enough energy to make up for that lost in the mechanisms.
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    Mar 19 2013: I don't think a sterling engine will be powerful enough but compressed air has been used as a mass storage of energy before. Typically they use a large geological formation as a tank to store the air. I believe the example I read was a coal powered electrical plant that wanted to run at peak efficiency. Instead of lowering its power during low load time it would compress the air the old unused underground coal mine and then use that air to drive generators at peak load. Other examples use salt domes as a storage tank.

    The loss of power comes from the fact that compressing gases causes them to heat up which can dissipate as an energy loss. Also, when gases decompress they get cold and this can cause mechanical problems with the turbines that drive the generators. To deal with this systems have been designed to use heat exchangers to capture and store some of the heat to reintroduce into the compressed air when it is released. Of course, there is always energy loss. As I understand, these systems are less efficient, but cheaper than batteries.

    If you want to do some research into what has been done in this area, Wikipedia is a good place to start.
    http://en.wikipedia.org/wiki/Compressed_air_energy_storage
  • Mar 18 2013: i don't want to use a url because you are proposing using unbelievably efficient machines (which we are nowhere near to making) to use a source of energy that is very very tiny
  • Mar 18 2013: well i could but i really don't need to your idea would use more energy in creating the energy it violates many scientific laws
    • Mar 18 2013: I am concentrating solar energy not creating it so I do not see where the law of thermodynamics applies. Maybe you should read my idea again before you flippantly copy an URL as your only explanation.
  • Mar 15 2013: no this would be highly inefficient
    • Mar 17 2013: It does not have to be efficient. If it runs on ambient air it would change the world. No more petroleum nor photovoltaics nor wind power needed. Please give science or physics explanations versus unsupported opinions. Thanks
  • Mar 14 2013: There is probably some law of physics that I am violating by thinking that there is enough energy in the air to run a sterling engine with enough power to run the air compressor that is creating the heat (and cold) that powers the sterling engine but I can't find it. I am thinking that I just need a very efficient air compressor. Can some one point out what I am missing? Thanks
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    Mar 14 2013: Ignorance. If you knew better, you would not harm self or others.
  • Mar 14 2013: I've read the idea of pumping water upward where the energy can be extracted by letting it run downhill. Kate's point is doubtlessly used and useful, but how clean is it to use batteries for storage? Again everything seems to be how do we choose the better or least bad solution. Maybe the bad guys are the fertility cult. Once America had ZPG then the business porkers decided to grow poverty, lower wages, etc. seeking their thirty pieces of silver.
    Oh yes, they don't want to pay more taxes to deal with the problems they have created. Pigs will be pigs.
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    • Mar 14 2013: My idea has no need for night time storage since it would run 24x7x365 even if the temp was below freezing.
  • Mar 13 2013: So you have an air compressor which is powered by a solar panel? Sounds like an indirect way of simply collecting solar light. The process between compressing the air and then using the heat from it to run a generator will be more likely to waste energy than conserve it.
    I see where you think the excess energy would come from: the atmosphere's heat, but there is an energy cost to extract that heat via compression, so it wouldn't have a net positive energy production.

    Correct me if I misinterpreted your design. It is easy to get lost in your description.
    • Mar 14 2013: No photovoltaics. The compressor is powered by the sterling engine. Why would the heat extracted not be enough energy to power the the sterling engine which runs the compressor?