Without access to the grid, the Alonsos added photovoltaics and hydro power and worked to ensure the home wouldn't use much energy. The original position of the stable worked to their favor. The southern exposure allows for the sun to be the main source of heat during the winter.
The Alonsos also added large wooden shutters that slide closed like a second skin, covering the large windows at night to trap in most of the home's daily solar heat gain. — http://faircompanies.com