How can I supply my own electricity?

Discussion in 'Highly Technical' started by Bird222, Nov 11, 2012.

  1. Bird222

    Bird222 Platinum Member

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    Specifically, by using solar panels and a wind turbine. What would be needed to sustain for example a 2000 sq ft. house with 4 people in it? How much would it cost, etc?
     
  2. nismotigerwvu

    nismotigerwvu Golden Member

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    You've left far too many variables to give a solid answer here. Even if we made a leap of faith and assumed you were talking about doing this in the US, the production you would net from the various sources fluctuates wildly throughout the country (how sunny/windy the climate is...ect). Even then we would need to know about the house itself (modern well insulated with efficient appliances) and how it is to be used (natural gas to heat or is the house to be completely off the grid from any and all sources up to and including water/sewage). That said, in favorable conditions with a large enough solar array and geothermal assist on the heating/cooling and a windmill to pump water and a massive battery array it could be done. The dollar value depends on the situation and usage (and how big of an area you have to setup a massive solar array to support that usage).
     
  3. Bird222

    Bird222 Platinum Member

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    Yes in the US. The house would be pretty well insulated with modern appliances. Natural gas to heat the house. Climate is pretty sunny, with low to moderate wind. Let me know if you need more details.
     
  4. ElFenix

    ElFenix Elite Member<br> Super Moderator<br>Off Topic
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    Long/lat would be a start
     
  5. fralexandr

    fralexandr Golden Member

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    Objective details would be helpful.
    what does pretty well insulated mean? are we talking about a house built in 1970? 2010?
    likewise pretty sunny could mean ANYTHING. Do you live in Southern California? Arizona? in the middle of a forest? New York City?

    An easy way to calculate your intended power draw is to check your electricity bill, and then go with solar/wind that exceeds that, based on what solar panels/wind generators you use, and average insolation/wind in your area (based on sunlight strength and duration/based on avg wind speed and direction and duration).

    Furthermore, as nismo indicates, you'd potentially need batteries sufficient to cover at least a few days worth of energy if you're going off the power grid.
    if you're still going to be attached to the power grid, you won't need batteries.

    typical households might require solar panels/wind capable of a few to several KW
     
    #5 fralexandr, Nov 12, 2012
    Last edited: Nov 12, 2012
  6. Bird222

    Bird222 Platinum Member

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    Let's say house built in late 90's in TN. Will still be connected to the grid as a backup/to supplement power.
     
    #6 Bird222, Nov 12, 2012
    Last edited: Nov 12, 2012
  7. Hitman928

    Hitman928 Golden Member

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    For wind, it doesn't look too good, unless you live right on the SC border (I don't know Tennessee geography very well to know how the population is spread):
    http://windeis.anl.gov/guide/maps/map2.html

    Solar doesn't look great either, though better than wind:

    http://solarenergy-usa.com/about-solar-energy-solutions/u-s-map-of-photovoltaic-solar-resource/

    How much square footage do you have available on your roof/property? These types of energy sources typically need a large foot print. Will you connect the solar/wind to the grid? If you go solar, you also must convert it to clean AC power as photovoltaics produce DC.

    I'm from AZ and there are companies here that will install solar panels to your home for this type of thing. It's usually very expensive though and the break even point is usually somewhere between 5-10 years away, depending on how much area you have to use. This is in one of the best solar resource areas in the world. In TN, it would probably take a lot longer. You can save a bunch of money by doing it yourself, but then you have to know how to install everything.
     
  8. Red Squirrel

    Red Squirrel Lifer

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    You'll also want a decent bank of batteries. Probably want flooded acid, equivalent to car batteries. You don't want to run them down till they die, but they are designed to be under constant charge. If you use deep cycle marine batteries, they're not really designed to constantly being charged/drained. They're better for a standby system. The heart of the system is the charge controller. Basically the variable DC source (panels or wind) goes in, batteries connect to it, then inverter(s) connect to the batteries to power the house. For wind you also need a rectifier as the output will be AC, and again, very variable due to the different wind speed. I would imagine the frequency would be variable too, but if you put a bridge rectifier that's not really relevant once it's DC.
     
  9. greenhawk

    greenhawk Platinum Member

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    So going grid connected. Any feed in tarrifs from your energy provider?

    current power usage (average daily would be best).

    How much are you looking at generating? enough to not have a power bill, enough to keep the bills down?

    Currently in Australia where I am, to get a zero power bill (mostly thanks to the high access charge), on a 14KHW per day usage (one person, gas heating), using current feed in offers,I would need a solar setup of about 6KW worth of pannels, which would be about $15,000K AUD at last check. Works out to be about a 11 year cost/break even period (ie: 11 years before I start to save money).

    but my north facing roof (being in the southern 1/2 of the world) is not large enough for that number of pannels. I would need a support setup to hold the pannels, which increases setup costs.

    Best bet if after information is to call some of the local solar installers for your area and have a copy of your power bill on hand for working out the size you would need.
     
  10. sm625

    sm625 Diamond Member

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    Your best bet is to generate electricity from the natural gas. No other solution would even begin to compete with the price of natural gas. You're talking an order of magnitude higher cost to go with air or wind vs natural gas, even for electricity. Something like a Generac 5882 is only $2000 and there is a huge well established market. You can get the thing installed and integrated for a fraction of the cost of a solar/wind system. And it can run off tanked storage, for months. You can still be off grid with it to a degree. Maybe not years, but why would that really matteR?
     
  11. A5

    A5 Diamond Member

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    If you're willing to spend a lot of money for something that won't pay-back for 10 years and needs to be replaced in 20, you can try to add a bunch of solar panels to your roof. I'm not sure the insolation in TN is high enough for a net-zero power bill to be practical, but you could do a small group of panels (like $4K instead of $12-15K) to offset some of it if you wanted.

    Unless you live in the Smokies, wind power would be negligible and too variable to rely on.
     
  12. Red Squirrel

    Red Squirrel Lifer

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    I was reading up on generacs as I had actually thought of that given natural gas is so cheap, but even their FAQ says it would still end up being more expensive. Also it's not really green to be burning all that fossil fuel when you could just be using commercial AC that comes from hydro dams.

    Now what would be cool is to live near a big enough stream and use hydro electric. :cool:
     
  13. jagec

    jagec Lifer

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    Someone fed you a line. True, the payback can be long (usually not 10 years, though), but the panels last a good deal longer than 20 years.
     
  14. Charles Kozierok

    Charles Kozierok Elite Member

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    Rough ballpark if you are looking at alternative energy, you're talking low to mid five figures by the time all is said and done.
     
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