One thing we know we want to do is get off the grid, at least primarily, for our electricity. I've worked briefly in the wind power field, hydropower won't work on a small scale, geothermal requires a heck of a lot of earth-moving from what I can gather. So solar it is. And I have an acquaintance who did the engineering for a company in New Jersey to outfit a Whole Foods to run on solar power.
The garage/office that we want to build seems like its roof would be situated perfectly for solar panels across one slope.
Walking around the neighborhood I've noticed quite a few homes with solar panels, but usually just 2-4 panels. I'm guessing they're not running off them entirely.
I used to babysit at a home in Vermont that was entirely solar, as solar installation was the father's career. They had low-wattage everything, and the lighting was quite dimmed in the evenings, but otherwise it seemed pretty straightforward. So we might have to outfit the house with all new lighting fixtures and a few other items.
Here's some info I found that might be helpful:
For Massachusetts residents: http://www.masstech.org/SOLAR/res2009.html
Free financial assessment for solar in the home: http://freecleansolar.com/installer_loans.php
A company that supposedly 'does it all' and maintains the installed system for 18 years: http://www.sunrunhome.com/affordable-home-solar
Also, we want to add a small inground pool at some point. We'd like to heat it, and we have friends who have a solar-heated pool that is really cool. So I'm sure I'll be picking their brains about that!