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<div dir="ltr"><font color="#000000" size="2" face="Tahoma">Drew,</font></div>
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<div dir="ltr"><font color="#000000" size="2" face="Tahoma">Aside from getting the weather data for weather-adjusted performance calcs, you might also note to your client that the excessive snowfall has skewed performance even further. One of our projects
just outside of NYC had a pyranometer that would be clear of snow the day after a storm and therefore showing say 400 or 500 watts/sq meter irradiance at the site. Meanwhile there was a foot of snow on the array! I suppose we should move the pyranometer
down to the module height so that it doesn't clear of snow any sooner than the modules.</font></div>
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<div dir="ltr"><font size="2" face="tahoma">It might also be comforting to point out that a 10 degree pitched system in Newark NJ could be down 100% in January and that's still only 5% for the year. If it starts snowing in July, then we have more problems
than lost PV production. </font></div>
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<div dir="ltr"><font size="2" face="tahoma">David Buckner</font></div>
<div dir="ltr"><font size="2" face="tahoma">Solar Energy Systems</font></div>
<div dir="ltr"><font size="2" face="tahoma"><a href="http://www.solaresystems.com">www.solaresystems.com</a></font></div>
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<font size="2" face="Tahoma"><b>From:</b> re-wrenches-bounces@lists.re-wrenches.org [re-wrenches-bounces@lists.re-wrenches.org] On Behalf Of Andrew Truitt [atruitt@gmail.com]<br>
<b>Sent:</b> Wednesday, March 03, 2010 10:35 AM<br>
<b>To:</b> RE-wrenches<br>
<b>Subject:</b> [RE-wrenches] Irradiance data<br>
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Is anyone aware of a resource for finding local historical irradiance data? We've had a cloudy winter around the DC Metro area and I would like to quantify how far down we are from the average for new customers concerned with production.<br>
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Thanks in advance,<br>
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Drew<br>
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<br>
-- <br>
"Don't get me wrong: I love nuclear energy! It's just that I prefer fusion to fission. And it just so happens that there's an enormous fusion reactor safely banked a few million miles from us. It delivers more than we could ever use in just about 8 minutes.
And it's wireless!"<br>
<br>
~William McDonough<br>
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