Have you looked into this:
http://sirewall.com/
There's a company in New Mexico that does similar work.
I'm familiar with rammed-earth construction, the Sire wall looks interesting... makes me wonder how it would hold up after many years.
Our house here in NC has solar and a windmill feeding a 12V battery bank, so that's an option. The builder (previous owner) ran power from the battery bank to one aux receptacle in each room, but more importantly to light fixtures in the bathrooms and closets. There are also some "mood lights" in the living room and kitchen that we use 99% of the time. It's free power! The battery bank is also hooked up to an inverter to change it to 120V. That is hooked directly to a small section of breakers in the fuse box in case of power outage. Our (120V) power bill has never been above $50. Not sure if it's because the 12V lighting helps or if we're just cheap.
Relying 100% on solar is a bit daunting, but there are options... And a well/septic are the way to go. If you have enough land there's no reason to pay for water/sewer.
My wife has a friend here in Colorado that has a massive, offgrid home with solar. It's an amazing building, but the cost all together is about 5x what I can afford...
I agree with having enough land, the problem out here is that there are places where drilling a well isn't an option, either too much alkali in the water and it's so bad it cannot be treated, or there simply isn't enough water. The price of land worth building is steep, too.