Re: [RE-wrenches] tubes versus flat surfaces
Tom, You mentioned 90% as best performance for flat glass. Do you have a corresponding number for tubes, in terms of losses due to reflectance? Anyone else have any data to share? Thanks, Jim Grundy NABCEP Certified Solar PV Installer Vermont Solar Specialist Plumber PS-279 Elemental Energy, Inc. 1750 Clark Rd E. Montpelier, VT 05651 802-476-3441 (p) 802-476-5680 (f ) 802-272-8933 (c) On Jul 22, 2009, at 6:15 PM, re-wrenches-requ...@lists.re- wrenches.org wrote: Message: 3 Date: Wed, 22 Jul 2009 14:29:29 -0400 From: "Tom Lane" Subject: [RE-wrenches] tubes versus flat surfaces To: Message-ID: <00e401ca0afa$5b06e240$1114a6...@com> Content-Type: text/plain; charset="us-ascii" Glazed collectors: i.e. evacuated tubes and flat plate collectors - the single one factor that effects the collectors efficiency is most is the Angle of Incidence of sunlight to the flat glass or curved glass cylinders. Typically in the best low iron glass at perfect orientation to the sun - only 90% of the sunlight gets through the glass while at least 10% gets reflected off the surface. No matter how efficient the absorber is in capturing the solar thermal energy - if only 90% get through - then 90% insolation x 90% efficiency means at a theoretically best is 81% efficient collector under optimal conditions. Evacuated tubes have an obvious distinct disadvantage to a flat surface - as the plane rotates away from the south. On east or west facing roofs, the back side of the tube curvature will typically be greater than a 40 degree angle of incidence from September 21st to March 21st above 40 degrees latitude. Rotating the absorber in the tube will not change the angle of incidence to the glass. In the summertime above 40 degree latitude the morning and/or afternoon sun will be north of a south facing absorber in the glass tube. IT IS IMPOSSIBLE for a tubular surface that covers the same area TO CAPTURE AS MUCH SUNLIGHT AS A FLAT SURFACE - as much of the surface on one side will always be curved AWAY from the sun. Even at direct 0 orientation at solar noon to a flat plate or evacuated tube facing south only the 10 o'clock to 2 o' clock position on a tube is in excellent orientation to the sun. TOTAL NONSENSE IS TUBULAR PEOPLE CLAIMING THE TUBES TRACK THE SUN! Please take a geometry class! PLEASE NOTE THIS IS TRUE FOR SOLAR ELECTRIC OR SOLAR THERMAL COLLECTORS THE ANGLE OF INCIDENCE TO THE GLASS IS CRITICAL. NOTE TO FOLLOW - IT IS ILLEGAL TO TO PUT ANNEALED GLASS ON A ROOF. Only tempered glass can legally be put on a roof. Gator tom Tom Lane Energy Conservation Services 6120 SW 13th ST, Gainesville, FL 32608 (352) 377-8866 F (352) 338-0056 Give Your Sun A Job <http://www.ecs-solar.com/> ___ 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] MC 4 connectors
Not sure if others have already answered this, but we have been getting MC4 connectors, tools set, USE-2 wire etc. from Framingham Winsupply 16 Everett St. Holliston, MA 01746 508-309-4437 i...@winsupplyre.com The fellow I spoke with was Kevin Price. They provided very fast and professional service. I can't say whether the price is comparable to other sources. And, this is a long way from the west coast or HI. Hope this helps, Jim Grundy NABCEP Certified Solar PV Installer™ Vermont Solar Specialist Plumber PS-279 Elemental Energy, Inc. 1750 Clark Rd E. Montpelier, VT 05651 802-476-3441 (p) 802-476-5680 (f ) www.elementalenergy.com On May 25, 2010, at 1:45 PM, re-wrenches-requ...@lists.re- wrenches.org wrote: Anyone have a good line on MC 4 locking connectors? Thanks, marco ___ 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] IE / Goldline TD-6 or equivalent
Thermal Wrenches, I am looking for a multi position temperature monitor that utilizes remote sensors with a distance capacity of 200' or more. This is for a combo wood boiler, solar thermal heating system supplying two buildings. The Goldline TD-6 would be adequate (if anyone has a leftover, please contact me off list). Since these have been out of production since 2005, I am looking for an equivalent. A single station monitor with a known, replicable sensor (10k thermistor preferred) could be made into a multi channel with a rotary switch. There are a multitude of digital thermometers with attached probe, but it seems hard to get info about the probe type or value. Any thoughts or experience is appreciated. Thanks, Jim Grundy NABCEP Certified Solar PV Installer Vermont Solar Specialist Plumber PS-279 Elemental Energy, Inc. 1750 Clark Rd E. Montpelier, VT 05651 j...@elementalenergy.com 802-476-3441 (p) 802-476-5680 (f ) 802-272-8933 (c) ___ 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] MPPT greater than 150V - Apollo T-80HV status
We received the following response from Daniel at Apollo after inquiring about them possibly scraping the high volt units. The statement is completely inaccurate. The T80HV has been running at beta test sites since November. It has passed all UL Certification Testing. We are now scheduled to receive the final paperwork on the UL Certification by Monday April 6, 2009, at which time we can release the unit for commercial sale. Thank you. Daniel Sounds like this may be a "real" product soon Jim Grundy NABCEP Certified Solar PV Installer Vermont Solar Specialist Plumber PS-279 Elemental Energy, Inc. 1750 Clark Rd E. Montpelier, VT 05651 802-476-3441 (p) 802-476-5680 (f ) 802-272-8933 (c) ___ 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
