<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div><span>Ray,</span></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: 'times new roman', 'new york', times, serif; background-color: transparent; font-style: normal; "><span><br></span></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: 'times new roman', 'new york', times, serif; background-color: transparent; font-style: normal; "><span>The "solar constant" -- the average irradiance value at the edge of the Earth's atmosphere -- is about 1360 W/m2. See the wikipedia article:</span></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: 'times new roman', 'new york', times, serif; background-color: transparent; font-style: normal; "><span><br></span></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: 'times new roman', 'new york', times, serif; background-color:
transparent; font-style: normal; "><span>http://en.wikipedia.org/wiki/Solar_constant<br></span></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: 'times new roman', 'new york', times, serif; background-color: transparent; font-style: normal; "><span><br></span></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: 'times new roman', 'new york', times, serif; background-color: transparent; font-style: normal; "><span>You're pushing the edge of what's possible if you're getting 1400 W/m2. There could be a slight calibration problem. The 1800 W/m2 must be the edge-of-could effect, or something is definitely going on with your pyranometer.<br></span></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: 'times new roman', 'new york', times, serif; background-color: transparent; font-style: normal; "><span><br></span></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: 'times new roman', 'new
york', times, serif; background-color: transparent; font-style: normal; "><span>Jeffrey Quackenbush</span></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: 'times new roman', 'new york', times, serif; background-color: transparent; font-style: normal; "><span><br></span></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: 'times new roman', 'new york', times, serif; background-color: transparent; font-style: normal; "><br></div><div><br></div> <div style="font-size: 12pt; font-family: 'times new roman', 'new york', times, serif; "> <div style="font-size: 12pt; font-family: 'times new roman', 'new york', times, serif; "> <div dir="ltr"> <font size="2" face="Arial"> <hr size="1"> <b><span style="font-weight:bold;">From:</span></b> R Ray Walters <ray@solarray.com><br> <b><span style="font-weight: bold;">To:</span></b> RE-wrenches <re-wrenches@lists.re-wrenches.org> <br> <b><span style="font-weight:
bold;">Sent:</span></b> Wednesday, August 29, 2012 1:26 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> [RE-wrenches] Max Insolation<br> </font> </div> <br>Hi All;<br><br>I was recently at a mountain top solar site (11,000 ft), doing some testing, and I measured insolation values that were averaging 1400w/m2, with a temporary peak (edge of cloud effect) that hit 1800w/m2.<br>Do I need to my meter recalibrated? Its the Daystar, and seems to be accurate, when we got some cloud cover, insolation dropped to 200-300 w/m2 as expected.<br><br>Interstingly the aging Photowatt 1000 modules were running at only about 60% of rated output current into a Blue Sky 3048 MPPT controller. So I'm also wondering if I have faulty modules. Back of module temps were about 95 deg F.<br> Any help on both the high insolation reading or Photowatt troubles would be great.<br><br>Thanks in Advance,<br><br>Ray
Walters<br><br>_______________________________________________<br>List sponsored by Home Power magazine<br><br>List Address: <a ymailto="mailto:RE-wrenches@lists.re-wrenches.org" href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a><br><br>Options & settings:<br><a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org" target="_blank">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br><br>List-Archive: <a href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org" target="_blank">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a><br><br>List rules & etiquette:<br>www.re-wrenches.org/etiquette.htm<br><br>Check out participant bios:<br>www.members.re-wrenches.org<br><br><br><br> </div> </div> </div></body></html>