Arizona Could be Persian Gulf of Solar Energy

Discussion in 'In the News' started by Chuck, Feb 24, 2008.

  1. Chuck

    Chuck just the messenger

    Power for 70,000 homes.

    [xfloat=left][/xfloat]Amanda Lee Myres - AP - Feb. 22, 2008

    Lots of sun available in the desert Southwest for solar - Ed

    PHOENIX — A Spanish company is planning to take 3 square miles of desert southwest of Phoenix and build one of the largest solar power plants in the world.

    Abengoa Solar, which has plants in Spain, northern Africa and other parts of the U.S., could begin construction as early as next year on the 280-megawatt plant in Gila Bend — a small town 50 miles southeast of Phoenix. The company said Thursday it could be producing solar energy by 2011.

    Abengoa would build, own and operate the $1 billion plant, named the Solana Generating Station…[rm][/rm]
    Last edited by a moderator: Feb 24, 2008
  2. Indigo

    Indigo Witch with wry sense of humor

    We *really* like the idea of clean energy for 70,000 homes. Once built, it should also take a huge load off the terrestrial (coal/gas/nuclear) power grid.
  3. southerncannuck

    southerncannuck Well-Known Member

    It's a shame that it won't be an American company
  4. Vooch

    Vooch Well-Known Member

    7% of germany's power now comes from wind & solar
  5. Bucko

    Bucko Well-Known Member

    I sure hope it doesn't really take all of the 3 square miles to only produce 280 megawatts. Not sure what the average home consumes in the desert southwest but 4Kw per home seems a bit on the light side.
  6. rweatherford

    rweatherford Times my Mileage by Six

    What else are they doing with those 3 square miles? Perhaps they can add some windmills too.
  7. Tochatihu

    Tochatihu Well-Known Member

  8. pdk

    pdk Beacon of Sanity

    Definitely not a hijack, as this is quite relevant, and hard data is quite appreciated.

    So, feel-free to double-check my numbers on this, but let's look at energy per square mile from this map:

    For Arizona (erring toward the conservative side of average) 6,500 Wh / sq m * 2,589,988 sq m / sq mi = 16,834,922,000 Wh / sq mi / day (sq meter to sq mile conversion provided by Google calculator).

    16.8 Gigawatt hours per day from one square mile of solar collectors? I'm thinking I've done something wrong here in my numbers. I checked them at least 3 times.

    While not all of that land will be used for just solar panels, and you'll certainly lose some energy in the conversion and transmission processes, you're probably still operating on the order of several GWh/day of actual usable energy if you can get a total of 1 square mile worth of solar panels from a number of sources. Holy s***.

    Also, for sake of comparison and context, 1 gigawatt hour is 3.6 trillion joules (per Google calculator), and coal has an energy density of 24 megajoules per kilogram (per wikipedia). So it theoretically takes 150,000 kg of coal to produce 1 GWh of energy, which is ~330,000 lbs, or 165 tons.

    Just for kicks, what would a home in Wisconsin generate (theoretically, keep in mind potential transmission and conversion losses)? I'm going to assume a "typical" semi-detached home, with a roof area of 72 sq m ( I'll also assume that due to conversion and transmission losses, as well as the fact that a roof can't follow the sun and not all of the roof will be exposed, that you'll only get 50% of the theoretical maximum.

    3,500 Wh / sq m (low side of average) * 72 sq m * .5 = 126,000 Wh / day = 126 KWh / day. That would help take quite a chunk out of my electric bill. Even at 1/3 total efficiency you're still talking about 84 KWh / day. Yikes.
    Last edited: Feb 26, 2008
  9. Tochatihu

    Tochatihu Well-Known Member

    It is pretty fantastic the amount of solar energy that falls on a square mile of sunny desert. I'll take a stab at some downgrades thereof.

    The watt hours map includes infrared that PV can't use. Maybe 50%
    Typical PV panels are 13% (20% cost much more)
    If you don't track the sun with them and just hang them at the latitude angle, 60%
    Areal coverage (gotta leave some space I guess) 75%
    Convert the DC to high voltage AC 80% (a real WAG)
    Transmission efficiency 95%

    Any of these could be revised up or down, but with all these efficiencies multiplied in series, I get 2.2%. If I am in the right ballpark, getting 2% of AZ sunshine out of the other end of a long wire should be doable. 3% might be pushing it.

    PV panels seem to be $5/watt; $55/sq. ft. retail. Maybe if you buy a square mile of them you could get $2/watt :) Writing the $400 million check is the problem; after that, 1 GWh of electricity per year from your chunk of desert.

  10. Right Lane Cruiser

    Right Lane Cruiser Penguin of Notagascar

    Actually, wasn't the article about generating electricity from solar heat? That should help boost the efficiency quite a bit over what PV can accomplish.
  11. Tochatihu

    Tochatihu Well-Known Member

    Right Lane, you are quite correct and now I feel dumb for not reading the initial linked article earlier. My only excuse is that PV panels were shown in the original post.

    I haven't any idea how to 'cost out" solar thermal. Probably Sandia Labs does.

  12. Right Lane Cruiser

    Right Lane Cruiser Penguin of Notagascar

    No worries, Tochatihu! I don't know where to look it up either...

    I wonder if this place could augment their facility with PV to capture lost energy? Most of the solar heat collection facilities use enormous banks of mirrors to direct all sunlight to a centralized area -- there is aways going to be some light that doesn't hit the designated area so I would think there would be some leakage they could capitalize on...

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