This award winning house in Wisconsin gets 70-80% of its heat from the sun and earth with passive solar energy and geothermal radiant slab hydronic heating.
Plus, the price wasn’t substantially higher than a regular house. It was all in the design that allowed a house in quite cold Wisconsin to heat itself through solar, geothermal, and a brick fireplace that radiates heat.
Just fyi for anyone looking for affordable local solar panel installers in their area, this is a great resource: http://www.getsolar.com