Kent, Nick,Great feedback on this utility line shading topic. So, what i understand from this is, yes there is a noticeable effect (loss of energy production) at the time of shading, but because of the short time period of shading, there is little reduction in overall daily output. Thanks to Enphase's slick per/module monitoring, issues like this can more easily be investigated and accurately noted.Any other remarks on utility lines shading arrays? Thanks to everyone else who commented on the 'solar resource tool' options. I think i'll pass on the ASSET and even hold off on the SunEye for a bit. I have been fairly satisfied with the Pathfinder myself, i was just putting out feelers as the ASSET was offered to me at a good price. cheers,benn DayStar Renewable Energy Inc. [email protected] HAVE A SUNNY DAY
Date: Thu, 9 Sep 2010 11:07:28 -0700 From: [email protected] To: [email protected] Subject: Re: [RE-wrenches] Wiley Asset Hi Kent: At my site, the wire is directly above the module, and the module is oriented with a 210 deg. AZ, and the shadow is there most of the day. It is a very clear, visible shadow and has had no effect on output. Strangely, that module has produced more power than any other module on the roof. So maybe it helps the output, I doubt that, though. Nick Soleil Project Manager Advanced Alternative Energy Solutions, LLC PO Box 657 Petaluma, CA 94953 Cell: 707-321-2937 Office: 707-789-9537 Fax: 707-769-9037 From: Kent Osterberg <[email protected]> To: RE-wrenches <[email protected]> Sent: Thu, September 9, 2010 10:50:38 AM Subject: Re: [RE-wrenches] Wiley Asset Nick, Depending on the hours that the shadow is on the module, that indeed may be the case. I have a similar circumstance with a recent Enphase installation too: the shadow of a triplex service cable about 6 feet away shadows the lower half of the array from sunrise until 7:00 am (in the summer it won't last as long but in the winter it'll last longer). During the time in question, the power output is reduced by nearly 20%, yet the energy output for the day is only reduced by 0.2% because the shadow doesn't last long and it occurs at a time when the power output is low. The effect on energy production depends on how large the shadow is, how long it lasts, and what hours it occurs. Kent Osterberg Blue Mountain Solar Nick Soleil wrote: Hi Kent: I am sure that aerial wires have very little impact on system outputs. I just checked the Enphase Enlighten data for a system I recently installed, which had a 1-2" to 3/4" wire bundle running just 5' above a solar modules. The wire cast a distinct shadow on the module in question, but upon reviewing the output of that module, compared with all other modules at the same orientation, I have found that there is absolutely no effect on the production. I am surprised that I can not even see any difference. That module has always produced within 99% of the other modules on that roof, and the total output of that module is as high or higher than the other modules! Nick Soleil Project Manager Advanced Alternative Energy Solutions, LLC PO Box 657 Petaluma, CA 94953 Cell: 707-321-2937 Office: 707-789-9537 Fax: 707-769-9037 From: Kent Osterberg <[email protected]> To: RE-wrenches <[email protected]> Sent: Thu, September 9, 2010 9:38:55 AM Subject: Re: [RE-wrenches] Wiley Asset Benn, At 25 ft a 1-inch power line subtends an angle of 0.2 degree. The sun subtends an angle of 0.5 degree, so the power line will not make a dark shadow on the modules - only 50% of the light can be blocked. Depending on the distance from the module to the wire, along the ray to the sun, the wire will probably block a little less light. But a 50% reduction in the light on a few cells will probably reduce the entire module output by 50%. A shadow every day for the hours you are talking about sounds like a pretty serious issue. Kent Osterberg Blue Mountain Solar benn kilburn wrote: Thanks for the feed back guys, much appreciated! Now, how would you calculate for power/phone lines running thru the Pathfinder's reflection. There are about 6 of them (the largest being at least 1") at least 25-30 ft away directly east of the proposed array location, and they are running straight north-south. On the Pathfinder they run btwn 9 and 11am in June and btwn 10:30 and 11:30 in December. Would the pathfinder software, suneye or asset pick up on utility lines at that distance? How much effect do they have on available sun output? And while i'm at it, how much do the 'software' tools pick up on the tips of leafless tree branches at say 25ft, 50ft? i'll try out that spreadsheet idea, nice one! cheers, benn DayStar Renewable Energy Inc. [email protected] 780-906-7807 HAVE A SUNNY DAY Date: Wed, 8 Sep 2010 20:05:08 -0700 To: [email protected] From: [email protected] Subject: Re: [RE-wrenches] Wiley Asset Benn: A colleague has used the Wiley took and calls it 'marginal.' I use the Pathfinder and I like the features Ray described. I wrote a very simple spreadsheet using the teeny numbers on the month lines to create 100% of any month. I highlight and delete any of the numbers that are shaded and the remainder is the percent of exposure for a given month. You can multiply the output of PV watts or any other production result for a complete production prediction. Easy and free. William Miller At 05:38 PM 9/8/2010, you wrote: I've used the Pathfinder for decades, so I'm partial to them. Great for on-site discussions of shading issues with the customer, as multiple people can see the shading at the same time on the spot. I've also used their Assistant software, and it works pretty well. You take a photo of the actual pathfinder from above, and then download the photo into their software. You can then calculate total annual impact of any shading in Kwh, or percentage of annual production. I've been quite happy with the system, and the price for a Pathfinder, and the software is much less than the Suneye, I believe. R. Walters [email protected] Solar Engineer On Sep 8, 2010, at 3:46 PM, benn kilburn wrote: Wrenches, I'm looking at trying out another 'solar site evaluation tool', the ASSET (Acme Solar Site Evaluation Tool) from Wiley Electronics. I'm looking for feedback on its performance and user-ability. I have been using the pathfinder which is great, but not the pathfinder software. Any comments on the ASSET or Pathfinder software would be greatly appreciated. Cheers, benn DayStar Renewable Energy Inc. [email protected] 780-906-7807 HAVE A SUNNY DAY _______________________________________________ List sponsored by Home Power magazine List Address: [email protected] 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 _______________________________________________ List sponsored by Home Power magazine List Address: [email protected] 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 No virus found in this incoming message. 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