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Solar array positioning in Charleston, SC

surfkayakers | Posted in Green Building Techniques on

Our home builder positioned our solar arrays facing east and southeast, but the angle is pitched east on both. One bank of panels are partially blocked by a large oak tree to the east, the roof of the building to the south, and a 2 level garage which partially obstructs the array (12 in each bank) eastward. The other array is pitched east and catches a glimmer of southern exposure sun, but is partially blocked by other large live oak trees to the south,

I didn’t know anything about solar and the builder represented that they did and even said they do a sun study. Now that we live in the house, I see our production is about half of what it could be.

The panels are manufacturered by CertainTeed. Any suggestions on what our options might be to improve the result? A large cost for very little return to the environment or our investment.

Thank you.

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Replies

  1. GBA Editor
    Martin Holladay | | #1

    F. White,
    In general, a PV array should face south (if you live in the U.S.) to maximize annual electricity production. However, if your property does not allow for a south-facing array because of shading issues, an east-facing or west-facing array is sometimes the best solution (or compromise). Electrical output will be lower than it would have been with a south-facing array, but the investment may still make sense, depending on your expectations.

    It's impossible to know from the information you gave us whether your solar contractor misrepresented the output of your PV array. If the solar contractor provided promises in writing, and if your system is metered, you need to compare the annual electricity production of your PV array to your contractor's written promises to see whether there was a breach of contract. If you feel that the contractor engaged in fraud, you may want to pursue the issue in small claims court.

    If your contractor didn't provide any promises in writing, I doubt if you have a case.

  2. charlie_sullivan | | #2

    It seems that there are two questions--one is whether your contractor is responsible for remedying the situation, and the other is what can be done to remedy the situation independent of who is paying for it.

    Generally speaking, options might include:
    * Moving the solar panels.
    * Changing the angles of the mounts.
    * Changing the type of inverter system that connects them to the grid.

    It's hard to know whether the first two are are all feasible without seeing your system (maybe upload some pictures).

    On the options of changing the inverter system, there are three common types of configurations. One option is a single "central inverter" mounted on the wall someplace like your garage of basement that takes dc power from all the panels and inverts it to ac and feeds it into the grid. Another option is "microinverters" on each panel that convert to ac on a panel-by-panel basis. Systems with microinverters work better than systems with central inverters when there is sun on some panels but not all. A compromise approach is to use "optimizers" on each panel with a central inverter in order to get some of the advantages of microinverters.

    So if you have a central inverter system now, converting to one of the other approaches could significantly improve your energy yield without moving the panels.

    If you don't know which type of systems you have, pictures, brands, and model numbers of the equipment might give us enough clues.

    If you can find a reputable solar installer in your area, they might be willing to visit and estimate how much energy you should be getting from your system and quote you on options to change it.

  3. Expert Member
    Dana Dorsett | | #3

    The Certainteed solar product lineup isn't standard rack-mounted solar panels- it's roofing-integrated solar, which is usually more expensive, and probably harder to move:

    http://www.certainteed.com/SolarRoofing

    You may be able to built a shed or rigid awning in a location with more favorable shading factors to re-mount them on, but you also have to install roofing on the house where they were mounted, etc.

  4. charlie_sullivan | | #4

    And they say they have a 25-year power generation warranty:

    "...one of the most robust solar warranties in the industry:
    CertainTeed is the only company to back both the solar PV system and the professional
    installation of the system by our network of Credentialed Contractors. You don’t have to
    worry about product or installation problems, CertainTeed has you covered."

    That's not the legal contract language, but it sounds like CertainTeed might actually remedy the situation even if your contractor isn't responsive, assuming the contractor is in that program.

  5. surfkayakers | | #5

    I appreciate all the thoughts around this, thank you so much. I will contact CertainTeed. They probably won't be willing to remedy as the installation is solid - just not positioned appropriately for optimal usage. CertainTeed did not do the install. The builder will not address it as I have tried to raise this with him. Although it was their decision on the installation site (despite advise to the contrary not in writing and a sun study which seems to have been largely ignored). His contention is that the panels are 'working as they should'.

    You can see the loss of production from the attachment- it is quite evident. This is the majority of the year.

    Homeowners depend upon the implicit integrity and knowledge of those we contract who present themselves as experts. In the end, we emerge poorer and wiser sometimes. It would have been helpful if the energy industry was able to inspect/enforce 'doing it right' in addition to promoting energy conservation to help protect homeowners from situations like this.

    The ironic thing is our house is USGBC LEED certified and it still accrued LEED points for solar, despite being positioning. It appears there is no governing entity for this field to protect the innocent.

  6. STEPHEN SHEEHY | | #6

    A friendly letter from your lawyer to the GC, with a copy to CertainTeed, may get some attention. Just because there is no written specification doesn't mean that you have no recourse when something is improperly installed. You should have been advised that the installation would result in low performance, so you could have reconsidered the investment in PV.

  7. STEPHEN SHEEHY | | #7

    duplicate post

  8. surfkayakers | | #8

    I may try a letter to Certain Teed. I agree that we should have been advised his choice. The solar hot water was properly placed (perhaps because sufficient room remained in the same poor location.)

    There is an implicit expectation on the part of the consumer when their website states that all or almost all of your electrical can be covered. At this time, the builder is advertising a $15 monthly bill from a neighbor who was on vacation that month (but not revealing that fact). I think that probably speaks volumes in itself.

    I would love to encourage this fledgling industry to protect consumers more.

    Thank you again for your thoughts and research. As Mr. Holladay suggests, because he was astute enough to avoid commitments in writing, hoping the builder would do the right thing is more than likely akin to trying to wrestle a slippery eel.

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