On 11.03.19 10:48, Chris Albertson wrote: > Another option. Here in So Calif on the "west side" home prices start > at about $1M. So the math works differently from say Rural Oklahoma. > A $25,000 electrical system only adds 2.5% to the price of the home > and less percent to the more expensive homes. So if you are building > a new house that will sell for over $1M (every house here is like > that) Tesla's "solar roof" can "work" because you save the cost of a > tile roof. > https://www.tesla.com/solarroof > People are skeptical of these so Tesla offers a lifetime warranty. > They claim a "forever" warranty. Not many conventional roofers will > offer a "forever" warranty but these are made of tempered glass and > you would never need a new roof.
My brother is wildly keen on that technology, and it looks great for more polar climes, but I'm a bit dubious of its suitability for conditions here. If a panel reflects 7% of insolation, and converts 20%, then 73% of the 1 kW/m² summer sun is absorbed. On a 45°C (113°F) day¹, panels will be over 70°C (158°F), requiring a lot of roof insulation. The white roof I've chosen is 77% reflective, and the 200 mm recommended minimum under-array airgap allows convective cooling, especially with the 30° roof angle. Better a shade sail than an in-built solar roofspace heater, I figure. (Here we put most of the insulation on the ceiling, much less under the roof.) Mind you, it's no hotter than a tile roof, is cool technology, and looks splendid ... I'd only have to beef up the aircon. Erik ¹ OK, only had one of those here this summer, but I'm on the coolest end of the mainland. _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
