PV Watts does not account for shading / etc. The NREL SAM model does a better job but is complex (as are most of the good models).
We use PVSyst which has models for module level electronics. 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 From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of August Goers Sent: Tuesday, May 14, 2013 5:51 PM To: RE-wrenches Subject: Re: [RE-wrenches] SE or SW Does PVWatts really account for hourly weather data such as overcast conditions in the afternoon? I think it just accounts for average solar radiation for a particular location on a monthly basis but I could be wrong. Anyone care to chime in? -August August Goers VP, Engineering o: 415.641.4000 m: 415.559.1525 www.luminalt.com<http://www.luminalt.com> <http://www.luminalt.com/> Reliable solar. Done well. By good people.<http://www.luminalt.com/> <http://www.luminalt.com/> People love us on Yelp!<http://www.luminalt.com/> <http://www.luminalt.com/> On Tue, May 14, 2013 at 4:26 PM, Jesse Dahl <dahlso...@gmail.com> wrote:<http://www.luminalt.com/> We do tend towards clear mornings and clouding up in the middle of the day. Today was a good example of it. I did use PV watts and didnt see a big difference between the two. Thanks Benn Jesse Sent from my iPhone On May 14, 2013, at 6:10 PM, Benn At DayStarSolar <b...@daystarsolar.ca> wrote: > Jesse, > A good decision can be based on, among other site/load specific details, the > site's "micro-climate". > > Do they tend to have clear mornings and cloudier afternoons/evenings? > ...or cloudy/foggy mornings and clearer afternoons/evenings? > > Maybe throw the different directions into PVWatts and see what it says, since > it is based on weather history (isn't it?) > > Good luck. > benn > Sent from a 'smart' phone, with touch screen keys. Please excuse shortcuts > and typos. > > On 2013-05-14, at 4:34 PM, Jesse Dahl <dahlso...@gmail.com> wrote: > >> Hello, >> >> I was asked to look at a site today for a homeowner looking for a grid-tie >> with battery-back up. They are Doomsday Preppers for lack of a better term >> and want certain loads if and when the grid goes down for good. Aside from >> parts selection, they have two roof lines, one facing SE one facing SW. the >> SW is very low slope and is only accessible with a ladder and climbing on >> the roof, the other is SE, much steeper slope and accessible from the ground >> or deck. I mention the access because of snow removal. We had lots of snow >> last year and I spent lots of time on my roof removing 8" snow falls. Both >> have good solar access. >> >> I'm inclined to chose the SE roof line, but I am interested in arguments for >> the SW. >> >> Thanks! >> >> Jesse >> >> Sent from my iPhone >> _______________________________________________ >> List sponsored by Home Power magazine >> >> List Address: RE-wrenches@lists.re-wrenches.org >> >> Change email address & 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 > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Change email address & 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 > _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address & 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<http://www.luminalt.com/> <http://www.luminalt.com/> 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. If the reader of this e-mail is not the intended recipient, or the employee, agent, or representative responsible for delivering the e-mail to the intended recipient, you are hereby notified that any dissemination, distribution, copying, or other use of this e-mail is strictly prohibited. If you have received this e-mail in error, please reply immediately to the sender. P Please think of the environment before printing this email
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