For that particular site, no. As far as I know a database is not being maintained. That is, what you see at any given moment is what you get. But I will check. Once we get into Spring and Summer with higher sun angles, I will be able to see what kind of clipping would have taken place since I have 245-watt modules on 300-watt micros. (It's the one and only beta test site in the state for these micros.) Any time I see recorded outputs of 226 watts or higher, I will know that clipping would have taken place if I had used M215s instead.
For me this boils down to several fairly simple points: 1) Clipping is not good since that represents harvestable solar energy that does not make it to the end user. 2) So when the choice of clipping v. no clipping is presented, no clipping is always, in principle, going to be the best choice. 3) Larger inverters--whether micro or string--are going to typically cost more than smaller ones. 4) Does it make sense to pay more upfront for more inverter capacity and reap the benefits of more delivered kWhs over time? One can perform detailed equations until the ripe mangoes fall from the trees (at least out here). But from an intuitive perspective, spending marginally more money upfront to minimize if not eliminate clipping, especially in areas like the tropics which can have frequent and lingering edge-of-cloud effects, makes the most sense to me. And, really, pairing up a micro with a nameplate rating of 215 watts and max output of 225 watts with a 255, 260, 265 watt or higher rated mod? Does that really pass the sniff test when there are not higher output micros out there? Put the choice to the consumer, educate them just a wee bit and how do you think they will decide? marco @ Marco: does your weather data source have a database of insolation and temperature over the year ? Best Regards, John Berdner General Manager, North America SolarEdge Technologies, Inc. 3347 Gateway Boulevard, Fremont CA 94538 USA (*Please note of our new address.) T: 510.498.3200, X 747 M: 530.277.4894 -----Original Message----- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of William Miller Sent: Sunday, January 27, 2013 8:05 PM To: RE-wrenches Subject: Re: [RE-wrenches] high insolation value and inverter undersizing Jesse: Do you have any way to compare the total harvest for the day for a given module in a "clipping" scenario versus an unclipping? The question I want to answer is: Do we improve production enough on the shoulders of the clip to justify the loss on the peak? Thanks, William Miller At 06:25 PM 1/27/2013, you wrote: >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. _______________________________________________ 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 CONFIDENTIALITY NOTICE: This e-mail and its attachments are intended only for the use of the individual or entity who is the intended recipient and may contain information that is privileged, confidential and exempt from disclosure or any type of use under applicable law. 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