Trading money for hassle. Hassle won. On Tue, Sep 22, 2015 at 9:25 AM, Chuck McCown <[email protected]> wrote:
> Yeah, their solar panel was a thin film rolled into a tube. They slid > that into a glass tube and injected some kind of oil in between. The > modules were arrays of tubes with a gap between tubes. > > They were better at constant out put, but they were really bad on watts > per square foot and dollars per watt. My son bought truckloads of them > when they went bankrupt. > > *From:* Cameron Crum <[email protected]> > *Sent:* Tuesday, September 22, 2015 8:01 AM > *To:* [email protected] > *Subject:* Re: [AFMUG] The dreaded annual "how to keep snow and ice off > my solar panels" thread > > Wasn't this sort of Solindra's idea? Tube shaped solar "panels" with a > white reflective surface underneath so that no matter the angle some part > of the panel was always getting light. It took more "tubes" but removed the > hassle of having to worry about angles and time of day. > > > > On Tue, Sep 22, 2015 at 8:23 AM, Chuck McCown <[email protected]> wrote: > >> Have you tried inverted panels? >> >> (Most on this list have probably heard this story before.) >> >> I had a mountain top site that lost about half of its power production >> after a big storm. Flew over it and found that one set of panels had come >> loose at the top and flopped over so they were facing the ground at an >> angle. Probably 30 degrees from horizontal. >> >> The snow on the ground was reflecting the sunlight up into the panels and >> they were actually putting out a surprising amount of power. Could always >> count on them being alive the day after the storm. I figured if I ever had >> to do an extreme high reliability site, I would build a white reflector on >> the ground and use inverted panels over it. Have to work on the geometry >> of the reflector and panels but it could be a useful emergency source of >> power in areas where snow and ice cause problems. You normally have the >> clearest skies and brightest sun the day after the storm. >> >> *From:* Steve D <[email protected]> >> *Sent:* Monday, September 21, 2015 10:37 PM >> *To:* af <[email protected]> >> *Subject:* Re: [AFMUG] The dreaded annual "how to keep snow and ice off >> my solar panels" thread >> >> Vertical panels is something we're experimenting with as well. Started >> ignoring "optimum" angles years ago and pushed the panels as steep as they >> would go with existing hardware (about 80-85) but it's amazing what will >> still stick. Last winter we had a freezing rain that built up ice on the >> bottom metal lip around the glass and the wet sticky snow that followed >> built up 4-5 inches on top of that, even at those angles. (Last year was >> honestly the worst year for our solar sites in the last few years.) >> >> We're in the process of beefing up and extending the angle brackets for >> the racks at two sites so that we can go all the way vertical. I think >> snow will be fine at one of the low elevation sites, but the high elevation >> I still half expect to see them covered in hoar frost. >> >> On Mon, Sep 21, 2015 at 1:17 PM, Eric Kuhnke < >> [email protected]> wrote: >> >>> If you're off grid and at latitude 35N or higher... The one thing you >>> should care about is cumulative kWh production in December and January. >>> >>> Try putting the panels at an 85 or 90 degree tilt (yes, really) facing >>> due south. You will produce a lot less in June/July but your winter >>> production will be maximized. This also has the effect of ameliorating snow >>> and ice buildup thanks to gravity. >>> >>> The US DoE NREL and other sources have a lot of research on latitude vs. >>> angle tilt of solar panels. Ignore everything intended for gridtie >>> applications and stuff like "tilt the solar panels at the same angle as >>> your latitude". There are some online calculators like pvwatts that will >>> show you your December and January production for a 45 degree tilt vs. an >>> 85 degree tilt. >>> >>> >>> >>> On 9/19/15 11:05 PM, Steve D wrote: >>> >>>> Maybe it's Saturday night exhaustion talking, but piping the exhaust >>>> from a standby generator toward the back of solar panels a bad idea? I'd >>>> expect it to not put heat on the panels in the summer except it's weekly >>>> exercise cycle but that shouldn't be too bad? LP too so shouldn't be any >>>> soot. Or would this just create one little hole of open panel and a pile >>>> of ice? Bad in general for the panels? >>>> >>>> If I did this again, I'd put the damn thing directly under the >>>> panels... these Onan's get stinking hot. My little "cool running", >>>> comparatively speaking, portable yamaha's will melt a two foot radius of >>>> snow around them if they run for a good length of time, all this heat going >>>> to waste! The Onan would probably clear the whole rack if it was sitting >>>> right below it. >>>> >>>> Grumble grumble... snow... something, something, curse words... >>>> >>>> Cheers, >>>> >>>> Steve D >>>> >>>> >>> >> > >
