Re: [RE-wrenches] Bifacial modules
Remember that Silicon Energies modules are not bifacial. Jesse Sent from my iPhone On Nov 1, 2011, at 4:13 PM, "Hans Frederickson" wrote: > For the Sanyo and Silicon Energy modules I’ve worked with, it is a very small > amount of light that actually passes through in the gaps between the cells. > You could do a simple ratio calculation by measuring the area of the gaps and > the area of the cells. Just guessing, I would say about 3-4%, if that. I > wouldn’t count on getting much daylight under the array except for what > bounces in from underneath. Depending on the height of the array and > reflectivity of nearby surfaces, the reflected light under the array can be > significant. Hope this helps. > > > > -Hans > > > > From: re-wrenches-boun...@lists.re-wrenches.org > [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Keith Cronin > Sent: Tuesday, November 01, 2011 1:04 PM > To: RE-Wrenches > Subject: [RE-wrenches] Bifacial modules > > > > Hi > > > > Was wondering if any of you have installed bifacial modules and know what the > % of light that comes through to a surface below the modules? > > > > Looking for a canopy type of installation/ application and wondered if you > have any #'s? > > > > Thank you~ > > > > Aloha, > > Keith > > ___ > 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 > ___ 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
Re: [RE-wrenches] Bifacial modules
Keith, This is easy to test. Simple take an irradiance sensor, turn it upside-down and test the irradiance on the bottom surface of any PV array. It will vary greatly based on exposure to reflected light and so on, but it will rarely be above 100 W/m^2. 10% improvement is an absolute maximum for any bifacial technology, and that is on the high side. Any claims above 10% are ignoring the physics of sunlight, reflectance of typical materials, and PV. Nothing wrong with bi-facials. They are beautiful to look at. I would buy them based on aesthetics, not on performance. Bill. From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Keith Cronin Sent: Tuesday, November 01, 2011 1:04 PM To: RE-Wrenches Subject: [RE-wrenches] Bifacial modules Hi Was wondering if any of you have installed bifacial modules and know what the % of light that comes through to a surface below the modules? Looking for a canopy type of installation/ application and wondered if you have any #'s? Thank you~ Aloha, Keith ___ 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
Re: [RE-wrenches] Bifacial modules
For the Sanyo and Silicon Energy modules I've worked with, it is a very small amount of light that actually passes through in the gaps between the cells. You could do a simple ratio calculation by measuring the area of the gaps and the area of the cells. Just guessing, I would say about 3-4%, if that. I wouldn't count on getting much daylight under the array except for what bounces in from underneath. Depending on the height of the array and reflectivity of nearby surfaces, the reflected light under the array can be significant. Hope this helps. -Hans From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Keith Cronin Sent: Tuesday, November 01, 2011 1:04 PM To: RE-Wrenches Subject: [RE-wrenches] Bifacial modules Hi Was wondering if any of you have installed bifacial modules and know what the % of light that comes through to a surface below the modules? Looking for a canopy type of installation/ application and wondered if you have any #'s? Thank you~ Aloha, Keith ___ 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
[RE-wrenches] Bifacial modules
Hi Was wondering if any of you have installed bifacial modules and know what the % of light that comes through to a surface below the modules? Looking for a canopy type of installation/ application and wondered if you have any #'s? Thank you~ Aloha, Keith___ 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
Re: [RE-wrenches] RE; ARCO Solar and Carrizo Plain
Hi gang. If you have any questions about this, please contact me OFF list. While this thread is interesting, and certainly a failed utility-scale PV facility's modules being dumped on the market could affect your business, this is off-topic for this list because it's really about politics of energy. Please, let's move it to the RE-bitching list, or maybe RE-markets. But let's keep this list on-target. Thanks. ___ 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
[RE-wrenches] treasury grant expiration and safe harbor rule
Hi, Could someone please point me to info on the details of how these rules work? Does construction start of the system(or 5% of system costs paid) have to be documented with the feds before the end of the year for safe harbor? Thanks. Kirk Herander VT Solar, LLC dba Vermont Solar Engineering NABCEPTM Certified installer Charter Member NYSERDA-eligible Installer VT RE Incentive Program Partner ___ 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
[RE-wrenches] RE; ARCO Solar and Carrizo Plain
ARCO built the place in the early 80s because of the late 70s energy crisis... *** The response to the '70s energy crisis, though it was about oil, included the formation of PURPA: The Public Utility Regulatory Policies Act (PURPA) is a law, passed in 1978 by the United States Congress as part of the National Energy Act. It is meant to promote greater use of domestic renewable energy. The law forced regulated, natural monopoly electric utilities to buy power from other more efficient producers, if that cost was less than the utility's own "avoided cost" rate to the consumer; the avoided cost rate was the additional costs that the electric utility would incur if it generated the required power itself, or if available, could purchase its demand requirements from another source. At the time generally, where demand was growing, this was considered to be the construction and fossil fuel costs incurred in the operation of another thermal power plant. This free market approach presented investment opportunity and government encouragement [$$$] for more development of environment-friendly, renewable energy projects and technologies; the law created a market in which non-utility Independent Power Producers developed, and some energy market players failed. http://www.ask.com/wiki/Public_Utility_Regulatory_Policies_Act So when the govt funds ran out [the utilities didn't do this out of the goodness of their hearts] the big RE displays were dismantled and it was back to business as usual. The lesson learned by the utilities was that, with a significantly lower cost, RE could be profitable. We have witnessed this around the world thx first to the wind industry and now to China for the collapse of the PV market. The key to the weak success of the PV industry was largely due to the definition of "avoided cost" which only includes the cost in dollars to generate the electricity. The definition clearly avoids references to any other secondary financial benefits like no emissions from burning dirty stuff to generate electric power. I recall a recent California legislative battle to redefine avoided cost to include something to do with geothermal [?] where the utilities lost the battle but the final outcome is still up in the air. ___ 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
