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For owners of solar panels, is their own roof the best location for those panels?

Discussion in 'Environmental Discussion' started by burritos, Feb 1, 2010.

  1. icarus

    icarus Senior Member

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    In the solar consulting business, what I tell my clients that long before they consider any PV, the first thing to do is conservation, do everything they can do to save total energy. After that, we encourage them to do more conservation, and then followed by a bit more! Then and only then should they consider installing PV.

    The equation we used to use was that every dollar spent on conservation would save about ten dollars in PV costs. That equation is not quite correc anymore as the price o PV has come down, and the price of many conservation regimes have gone up, but the priciple is still the same.
    ttt
    I hear all the time about people with huge houses, huge (wasteful) loads and t hey want to "go solar". IMHO putting 10 kw of PV on your house to power waste is not really a scenario that makes much sense.

    Icarus
     
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  2. xs650

    xs650 Senior Member

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    The community I live in has quite a few homes with PV arrays on the roof. A few years back our community association arranged for several of them to hold an open house so other residents could go see the installations. Most of the ones I saw were heavy electricity consumers, frequently with a large water feature and pump or other power suckers.:eek:
     
  3. tripp

    tripp Which it's a 'ybrid, ain't it?

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    well, at least they felt guilty about their waste of energy. That's about all you can really say, however. Clearly they have money to burn.
     
  4. xs650

    xs650 Senior Member

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    But do the taxpayers that have heavily subsidized their installations have money to burn?:eek:

    I don't have any big objections though because they are getting PV systems out in public view showing Joe Sixpack that PV can work. They are also funding getting an industry in place to start serious home and small business PV installations when they make true economic sense.
     
  5. drees

    drees Senior Member

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    Money spent on conservation and efficiency will nearly always be best (which is why programs like "cash-for-caulkers" are highly beneficial), but in the end, it doesn't really matter if the PV subsidy is put on a high consumption house or a "passive-house" - the grid doesn't care.

    If you're looking to maximize return on investment, you'd build the subsidy more like the California program where the rebate is either based on the estimated system output or per kWh of generation instead of a flat percentage based on installation cost.

    Perhaps you'd also want to adjust the rebate based on how clean or dirty the grid is in the area as well - as you'd also want to encourage more development in areas of dirty coal plants (like Virginia) rather than areas which are very clean (like the northwest which gets most of their power from hydro.
     
  6. austingreen

    austingreen Senior Member

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    The rebate here is $2.50/watt and is maxed out at 6KW systems for residential. The cap is about the taking from the poor rate payers and giving to the people in huge wasteful houses. I'm not sure how that compares to California.
     
  7. drees

    drees Senior Member

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    Most of CA is $0.35 / watt (not DC watt, but calculated based on estimated system output - for example, my 3.24 kW system counted as 2.7 kW which matches real life peak output), SC Edison customers are still at $1.10 / watt.

    http://csi-trigger.com/

    $2.50 / watt cuts the price in half around here - not even counting the federal 30% tax credit.

    Not quite sure what you're saying here - are you referring to the 6 kW cap? Either way - wasteful houses pollute extra - and those people still need to pony up for the rest of the PV system.

    Community solar projects where anyone is able to buy into a larger system and have it's production deducted from your bill is still the best way to address the inequality issue for people who can't afford a full system or don't have the land to build one. For example, I would love to be able to buy into another 1-2 kW of solar to completely offset my electricity usage - adding another 1-2 kW is still not cost effective (primarily due to permitting fees - $350!) - typically about 3 kW is needed to get decent economies of scale.
     
  8. austingreen

    austingreen Senior Member

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    Yes the 6KW cap. These are heavily subsidiesed systems by the rate payers and it was done to address the issue icarus brought up above. Then again we are not subsidizing these at anywhere near the rate they are in germany. It is a city owned utility and there is much politics involved. Some people want as much reusable as possible no matter what it costs. Solar installations also have low interest loans available.

    We have green choice here, and my wind is 9.5 cents a kwh. New wind customers are 11.5 cents locked in for 5 years. Current price of non-green choice is around 10 cents. Brightsource building a 30MW solar system on city land and it will be offered by green choice but as it is much more expensive than wind they don't expect that it will be sold. It is likely that cost will be passed along to all rate payers as are these solar rebates as a surcharge on the bill.
     
  9. Dave7

    Dave7 Junior Member

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    PV on roofs is economical because there is already a mounting structure. Ground mounts tend to be more expensive with trenching, concrete foundations and supporting structures. Some times it is worth it, for optimization of tilt, sunlight access and azimuth. Some folks roofs just won't work.

    Community solar in CO just got a big boost with some new legislation. It would be nice to be able to offer that option to people that have objections or no space on their property.