A large part of my collection is CA. native species- legally collected/aquired animals only. I do have a few odds and ends that are not native as well. It is my goal to have 1 of each species that I can legally have, apart from the very few that I may not be able to provide a steady captive diet for. I like to do presentations with them occasionally.
I tried to keep a Sharp tail in the past- I did not do well with it. According to books, they eat slugs and slender salamanders- but in my personal experience- they just eat slender salamanders(nearest slender habitat is 1.5 hours away).
I have not looked into solar power. I would love to hook my entire house up to solar- but the initial cost will need to come down some first- or my bank account balance will need to rise.
I did put quite a bit of work into the insulation of the room, so that helps with power useage. I also cover the windows with 2 inch thick foam panels- rated at R-13. The ceiling has 6" deep blow-in insulation that I spread by hand. The walls have R-13 under the sheetrock. The prehung steel door insulates great too.

For me, having a separate building is great- not all house visitors want the "reptile experience" and sometimes, like if an insurance man comes or something- it is best that they dont see them. This keeps the animals safe and out of site for all but those who want or need to see them.