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Most efficient way of making electricity

  1. Aug 16, 2008 #1
    well im not sure if this is the right thread cuz im new, but i wanted to know. what are the most efficient ways of making electricity besides nuclear? Is there a way to create a lot of electricity from a relatively small source? Is there any new research or development of this topic?
     
  2. jcsd
  3. Aug 17, 2008 #2

    Defennder

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    What do you mean by "small source"?
     
  4. Aug 17, 2008 #3

    russ_watters

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    Efficiency is typically measured thermodynamically and using thermodynamics, nuclear power is the least efficient of the standard methods of power generation. A good combined-cycle gas turbine can be 60% efficient at converting the energy of the fuel to electricity. Nuclear power plant thermodynamic efficiency is on the order of 35%.

    But perhaps that isn't what you were asking...?
     
  5. Aug 17, 2008 #4
    well is there a way to create a lot of electricity from a small source? Like a really powerful fuel cell? or a super battery lol? as an example, would it be possible to power an entire house with something as small as a shoebox?
     
  6. Aug 17, 2008 #5

    russ_watters

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    So you're looking for an amount of power per a size. Sort of a power density. No, there isn't anything that exists or is on the horizon that would have a power density high enough to power a house from a shoebox-sized device.

    Why would this be important?
     
  7. Aug 18, 2008 #6
    i just thought it would be interesting to know thats all. thanks for the post
     
  8. Sep 24, 2008 #7
    Efficiency is rather academic.. Cost is the important thing.

    A fuel could have a high calorific energy content but the conversion to electricity is wasteful.

    Another fuel could have a low calorific energy content but the conversion to electricity is not so wasteful.

    Either is possible but the one which wins is the one where the overall cost is lower.
     
  9. Sep 24, 2008 #8
    What I would like to know is what has the best Cost to operate and build to energy output ratio
     
  10. Sep 24, 2008 #9

    russ_watters

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    Welcome to PF. That's two separate questions you asked there. The cheapest to build is a gas-turbine (jet engine) plant. The cheapest to operate is any kind of fuel-less power plant (wind, solar, hydro).
     
  11. Sep 25, 2008 #10

    Mech_Engineer

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    I would also say the best power-per-volume (or power per weight for that matter) power systems are gas turbines. Multiple-megawatt gas turbines are surprisingly small, some of their support equipment can take up 10 times the space that the turbine itself requires...
     
  12. Sep 25, 2008 #11
    I would like to know why waste to enegy plants are not more popular. During the early 90's I toured a powerplant just outside of Spokane, Washington that uses refuse exclusively as a fuel source, instead of sending it to a landfill. This seems like a better idea that dumping all that garbage in a big hole and hope that there aren't any pollutants in there.
     
  13. Sep 25, 2008 #12

    mgb_phys

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    NIMBY (not in my backyard) - it takes about as long to get planning permission for an incinerator as it does to build the pyramids.

    To ensure that all the toxins are completely destroyed you have to run the burn at a very high temerature, so you have to add a lot of fuel. Unless the costs of waste disposal is very high, or the waste is presorted to be mainly paper/card/compostable etc it's not worth it.

    It is worthwhile to burn garbage/waste oil etc in a cement kiln - these already run at a temeprature high enough to destroy dioxins. But then they get classified as incinerators and the planning problem starts.

    Extracting methane from old capped off landfill and burning that in a gas turbine isgenerally worthwhile.
     
  14. Sep 30, 2008 #13
    well,a battery made of matter-antimatter could do the trick...the only problem is,for every gram of antimatter you would need about 1 tone of electromagnets,so it isn't that volume eficient,unless you want all the energy consumed in 1 moment,not to mention,to produce 1 gram of antimatter is an incredebley hard job,would take years,mabey,but as a simple concept,this should do...
    here,have a quote from a book from reader's digest-the misteries of terra:
    "the amount of antimatter that the scientists have is enough to light a 100W light for 1 hour,and the antimatter left in the universe is enough for the light to function 100 hours"
    so to produce antimater as we know to produce is very ineficient!
     
  15. Nov 22, 2011 #14
    actually the plant in Spokane from earlier in the post is a RESCO plant and the only time that they use and fuel (natural gas) is after they clean a burner and turn it back on. Other than that the heat of the burning trash keeps the the fire burning. The burning ash heats water to steam to turn a turbine to make electricity and at least for the Baltimore one it also provides steam to the heat district for building warmth. The steam is then condensed back into liquid water circulated over the steam pipes using water from the surrounding waters. Then the ash is finally taken to a landfill. all the off gasses are "cleaned" with scrubbers, and electromagnets (for the mercury) and other filtration systems. they still let off lots of co2 so its not the best system but it works and ash takes up much less room in the landfill.

    origanaly posted mgb_phys by
    NIMBY (not in my backyard) - it takes about as long to get planning permission for an incinerator as it does to build the pyramids.

    To ensure that all the toxins are completely destroyed you have to run the burn at a very high temerature, so you have to add a lot of fuel. Unless the costs of waste disposal is very high, or the waste is presorted to be mainly paper/card/compostable etc it's not worth it.

    It is worthwhile to burn garbage/waste oil etc in a cement kiln - these already run at a temeprature high enough to destroy dioxins. But then they get classified as incinerators and the planning problem starts.

    Extracting methane from old capped off landfill and burning that in a gas turbine isgenerally worthwhile.
     
  16. Jul 8, 2012 #15
    As others have said, not sure if this is the correct place to post, but new to the site.
    I have created a solar panel from scratch, using a DIY manual. I am stuck on the conversion phase, as I follwed the DIY instructions to the letter & my inverter blew up when connected to the AC side of the circuit. The DIY support staff has not returned my requests x 3 weeks, so I guess I am on my own. Suggestions please... The panel produces between 15-18V. Circuit is good up to inverter as I have been able to charge a 12V battery with a direct connection from the panel.
     
  17. Jul 8, 2012 #16

    jim hardy

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    hmmmmm how is it synchronized?

    Ever drive a stick shift car and hear the gears grind?
    That's why newer ones (post 1963) have all forward speeds "synchronized" .
    Same thing applies to your inverter - if it's not matched speed and voltage to grid, it'll be violent when switch is closed. That matching procedure is called 'synchronize'.

    See this thread, second post.
    https://www.physicsforums.com/showthread.php?t=594556
     
  18. Jul 8, 2012 #17
    Good to know why... can you suggest something synchronized to get my system rolling?
    Thanks
     
  19. Jul 9, 2012 #18

    sophiecentaur

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    If you tried to connect directly to your mains supply then your supply company will not be very pleased with you. If you want them to allow you to do that then you will need a lot of experience and 'letters after your name' to prove you are competent. A lot of the cost to the consumer for Feed In Tarif schemes is to pay for that expertise.
    If you are just trying to connect an inverter to the DC you have produced, for feeding a local AC load, then that should be less of a problem. Did you connect the inverter correctly and is it for the correct voltage? (Sorry but the question needs to be asked). It would be best to test such a set up with no appreciable load on the inverter.
     
  20. Jul 9, 2012 #19

    psparky

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    I don't know if it's the most efficient, but many, many years ago someone was boiling water in a tea pot and they noticed steam being forced out of the tea pot.

    Most modern electric plants use high pressured steam to turn their generators. They often use 15 story high boilers (big tea pots) to create this massive pressure. They heat the water by nuclear heat or the more common coal.

    They now clean the air using scrubbers to clean the coal exhaust. It's a massive system but they essentially crush up limestone and spray it through the coal exhaust. Limestone is a base and it neutralizes the acid. Then, the used limestone gets scraped out and they turn it into drywall. I was lucky enough to visit the electric power plant on the Indiana, Ohio border, just south west of Cincinnati....I forget the name of the plant.

    The mighty Titanic ship was powered by coal....that heated steam that turned the propellers of the ship...and powered all the electric on the ship. However, that ship sunk....but that's another story.
     
  21. Jul 9, 2012 #20
    I never would have guessed nuclear power would be so inefficient. Where are all the losses or why is it the least efficient?

    I'm guessing nuclear fuel is one of the most efficient sources we have as energy/kg, but that's a different definition of efficiency.
     
    Last edited: Jul 9, 2012
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