re: daryl hannah - living off grid
26 sep 2005
>...covering the roof with solar collectors would be extremely expensive...
>same with heavy insulation...
how about a sunspace? my 14'x96' plastic film tomato greenhouse kits cost
about $700 each, standard labor to put one up in a field (including the
"foundation") is 3 people-1 day.
>unless your thermal mass is big enough to carry heat from the fall, you
>still have to deal with the fact that the solar collectors are basically
>useless for 2/3 of the day during january and less than that for the month
>due to cloudy days.
thermal mass (water :-) is cheap, and we don't need seasonal heat storage
below the arctic circle, just enough for a few cloudy days. cloudy days are
like coin flips. if a building can store enough heat for 1 cloudy day, it
can be 50% solar-heated... 2 days makes 75% max, 3 make 87%, 4 make 93, and
5 make 97% possible, with low-cost materials and serious engineering.