[palmer]

Home insulation is great but passive solar is a quantum leap. It doesn't work well when it is cloudy without a large heat mass and supplemental heat. Many homes are poorly built and poorly sited and will be hard to fix.

We all agree on concentrated energy sources. I think a solar thermal plant would also need a natural gas option for a couple days of blizzard conditions (when you need the power the most).

[wolf78]

Home insulation is great but passive solar is a quantum leap.

Of course - but one doesn't exclude / contradict the other. And there have been real quantum leaps with home insulation, too, lately. Using nanotechnology / aerogels you can now have super-high-R-value panels that are thin enough to use in / on practically any building (ok, they are too expensive for shoddily built summer homes).

We all agree on concentrated energy sources. I think a solar thermal plant would also need a natural gas option for a couple days of blizzard conditions (when you need the power the most).

True. And while there is not enough biogas (from sewage, manure) to replace natural gas year-round, there might just be enough for a these few days (storage is not so much a problem, there are already huge natural gas storage caverns).