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Thread: Anti-solar AHJ's

  1. #1
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    Anti-solar AHJ's

    We have one that claims to grant rebates, but to qualify the array has to have an azimuth between 180 and 270 degrees and tilt between 45 and 80 degrees. That's not a typo and they have not confused tilt with elevation. That means that virtually no residences will qualify for rooftop systems; in ten years of designing solar in Texas I have seen roof tilts of 45 degrees only a handful of times and more than 45 degrees exactly never.

    These are the same guys that require all PV systems to be interconnected on the line side of the customer's meter. Yes, the meter, not the service disco.

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    I think these meters would allow such a connection:
    https://newenglandcleanenergy.com/en...ers-for-solar/
    At my age, I'm accustomed to restaurants asking me to pay in advance, but now my bank has started sending me their calendar one month at a time.

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    Isn't 30 degrees the ideal tilt for a fixed system? If I remember correctly, that's what we were setting them at in North Carolina when I did 1.35 Mwatts worth.

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    Quote Originally Posted by Coppersmith View Post
    Isn't 30 degrees the ideal tilt for a fixed system? If I remember correctly, that's what we were setting them at in North Carolina when I did 1.35 Mwatts worth.
    Yes, but that's not what they are going for. They did some research and found that PV arrays at between 180 and 270 degrees azimuth and between 45 and 80 degrees tilt will produce the most energy between 3PM and 7PM when their demand is the highest.

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    Quote Originally Posted by augie47 View Post
    I think these meters would allow such a connection:
    https://newenglandcleanenergy.com/en...ers-for-solar/
    They won't do single metering here, because the paynback PV is 1/3 the normal poco KW $$$

    ~RJ~

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    Quote Originally Posted by ggunn View Post
    Yes, but that's not what they are going for. They did some research and found that PV arrays at between 180 and 270 degrees azimuth and between 45 and 80 degrees tilt will produce the most energy between 3PM and 7PM when their demand is the highest.
    But that doesn't make any sense. One gets the feeling they've defined tilt for the vertical instead of the horizontal, opposite from everyone else.

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    Quote Originally Posted by Coppersmith View Post
    Isn't 30 degrees the ideal tilt for a fixed system? If I remember correctly, that's what we were setting them at in North Carolina when I did 1.35 Mwatts worth.
    Ideal tilt is basically latitude, perhaps adjusted for weather, but also on whether you want to adjust for economic considerations. For example if you have a rate schedule that pays back higher rates in summer, you'd want a shallower tilt. Or it might be more cost effective to squeeze more panels in the space you have at less than optimum tilt so they don't shade each other. Or if you are off grid you might want to maximize winter production. It all depends.

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    Quote Originally Posted by jaggedben View Post
    Ideal tilt is basically latitude, perhaps adjusted for weather, but also on whether you want to adjust for economic considerations. For example if you have a rate schedule that pays back higher rates in summer, you'd want a shallower tilt. Or it might be more cost effective to squeeze more panels in the space you have at less than optimum tilt so they don't shade each other. Or if you are off grid you might want to maximize winter production. It all depends.
    Actually for the nitpickers among us, ideal theoretical year round tilt is about 6-7 degrees less than latitude for most of the 48.

    https://www.solarpaneltilt.com/
    Ethan Brush - East West Electric. NY, WA. MA

    "You can't generalize"

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    Quote Originally Posted by jaggedben View Post
    But that doesn't make any sense. One gets the feeling they've defined tilt for the vertical instead of the horizontal, opposite from everyone else.
    That's what I thought initially as well, but we've exchanged several emails with their engineer, and he has stated unequivocally that 45 to 80 degrees off the horizontal is what they mean. The center of their "ideal" time window is 5PM in the summer months, not noon. He sent us demand curves and graphs from NREL to illustrate it. 45 to 80 degrees tilt and 180 to 270 degrees azimuth is what they mean.

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    Quote Originally Posted by ggunn View Post
    That's what I thought initially as well, but we've exchanged several emails with their engineer, and he has stated unequivocally that 45 to 80 degrees off the horizontal is what they mean. The center of their "ideal" time window is 5PM in the summer months, not noon. He sent us demand curves and graphs from NREL to illustrate it. 45 to 80 degrees tilt and 180 to 270 degrees azimuth is what they mean.
    Yeah, but while 80 tilt at 270az might be a reasonable range for that, 80deg at 180az is totally not. So it still makes no sense at all. I think your subject line is more insightful.

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