I built a passive solar house in the sixties that actually looked like a normal house....cedar siding, cedar shakes and such. Lots of south facing glazing, thermal curtains, super insulation, thermal mass and a water source heat pump. Got it good and efficient, then promptly sold it and moved south. /forums/images/graemlins/tongue.gif
I too am researching and here is my .02. Dan put his finger on the essentials....unless you are out to make a social or political statement, it boils down to payback timeframe.
Most efficient of all is hydro...a couple hundred GPM with a hundred or so foot of fall can generate all the juice needed. I figure by doing most work myself, using the grid as a virtual battery, I should get in for under 12K with a ten to twelve year payback...after that with exception of maint costs, the power is free. /forums/images/graemlins/grin.gif ...but, as with all of life, easier to talk about than do it....I'll let you know when I flip the switch. /forums/images/graemlins/smirk.gif
IMHO, if we wait about three years, stationary fuel cell systems will be availaible...the lead mfgr as far as I know is a company called Plug Power....in an exclusive marketing agreement with GE. These things are already being sold commercially here in the states and for residential use in Japan. (Maybe their emergence is why the power companies were so anxious to sell the California power grid infrastructure to taxpayers /forums/images/graemlins/shocked.gif /forums/images/graemlins/grin.gif)