> but I think it's a pretty safe bet that the embedded energy > of the PV system loses against passive solar.
10 years ago yes. Now, not at all! Just google for "solar thermal is really,really dead"... Here is the article that comes up. https://www.greenbuildingadvisor.com/article/solar-thermal-is-really-reall y-dead Remember there has been a THIRTY-to-ONE cost effectiveness improvement in water heating with heatpumps and PV, because solar has gone down 10-to one in cost and HP efficiency improves heating by 300%. Stop clinging to long held misbeliefs about solar thermal. AND the cost of a solar system has gone down another 25% since even that article was written! He used $3.75/W for solar when it is now like $2.75 Plus he does not even mention the wasted assets in a thermal system when one does not use 100% of their solar water every single day. Whereas with PV/HP thermal grid-tie, you get 100% retail for every photon that falls on your roof whether you use it for water heating or not. (depending on yoru state's net-metering deal)... As he says, the economics of solar thermal water heating are dead, dead, dead. Bob -----Original Message----- From: EV <[email protected]> On Behalf Of Jan Steinman via EV Sent: Thursday, July 18, 2019 5:28 PM To: [email protected] Cc: Jan Steinman <[email protected]> Subject: Re: [EVDL] Solar off grid with an EV? (DC AC/heatpumps and waterheating) > From: Lee Hart <[email protected]> It's like the "ICE" solution > wins. When you treat oil supplies as "limitless", then extremely > inefficient ICEs are the popular choice, because it's cheaper. Thanks for that, Lee. I don't have numbers for a full-on "EMERGY" analysis of the two, and have no desire to get into a religious argument, but I think it's a pretty safe bet that the embedded energy of the PV system loses against passive solar. And then there's the whole complexity argument: boxes full of power electronics and microprocessors, rotating components, rare-earth materials, etc., versus the sheer simplicity of a drain-back system that only uses copper, aluminum, and some tubing. The entire "dollars and cents" argument doesn't make any sense in a world that is awash in fracked oil, produced at a loss, in our zeal to keep civilization humming along. But I can tell you which system I'd rather have if civilization crashes, and it won't be the one powered by a stream of diesel-powered UPS trucks, delivering replacement parts! I'm reminded of the Panarchy model, which posits that complexity is powered by energy. If you think energy is going into decline, you should be seeking simpler solutions, not more complex ones. Jan _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
