A while back (3 years)I installed a system (bid spec) for a school that used 215W RECs and D380s on a dual axis tracker. With the ability to monitor the array, I see constant clipping. The modules will usually produce 199Ws regularly. A few days ago we had temps of -34F and clear skies. My array at home had one of its best days this winter. I have Tigos on so I can monitor watts, current, temp and voltage. I was seeing anywhere from 215W to 223W from my modules between 11:30am and 1pm. The modules on the tracker were still producing 199W. I didn't get an irradiance reading that day but my Tigos showed above IMP readings and way above VMP reading that day.
I've only been doing this for 6 years, so I don't have the experience that some people on this list have, but it seems foolish to me to waste that production. It's kinda site specific, but where I live the cold temps and snow reflection seem like something we should be utilizing. I'm interested in the thoughts of others. Jesse Sent from my iPad!!! On Jan 27, 2013, at 5:00 PM, "Marco Mangelsdorf" <ma...@pvthawaii.com> wrote: > I have had a concern for a long time that as PV modules have gone up in > output that there is inevitably going to be more and more clipping taking > place as they’re paired with comparatively lower output inverters. In > effect, matching, say. a 260-watt module with a micro inverter with a max > output of 225 watts reduces that 260-watt mod to 225 watts. It’s not a > matter of if clipping will take place, but how much and how much actual > harvestable energy will be lost. > > Out here in the tropics, even in January with the lower sun angle, we see > irradiance levels well above 1,000 watts/square meter range. Take a look at > what I copied today from a weather station that we installed at nearby > installation. > > Given the clipping issue inherent in using undersized inverters, it seems to > me that moving to larger output micros makes a whole lotta sense. I’ve got > one of the first installs using the Power-One 250-watt and 300-watt micros > and am so far quite impressed. Why use a 225-watt rated micro with a > 225-watt or higher output mod when larger micros are now readily available? > > What are the views out there regarding this clipping issue? Is it as minimal > as our Enphase friends suggest in their latest white paper or more of an > issue as I conclude? > > marco > > > Environmentals from Weather Station at a Hilo, Hawaii installation > > Sunday, January 27th 2013, 12:40:00 pm > <image001.png> > > Ambient Temp. 25.30 °C > Cell Temp. 41.70 °C > > <image002.png> > > Insolation 127.81 kWh/m² > Irradiance 1,175.00 W/m² > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org >
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