Earth Sheltered Dome Home – passive annual heat storage?

Has anyone got one, seen one, what are your views of these differant style homes?

http://www.dailymotion.com/video/xhh16i_home-and-garden-show_news

We are planning to build an earth sheltered dome home in SE Minnesota per www.earthsheltertech.com. It will have two modules plus an underground garage. We visited two homes/owners and they like them very much, as did we. We will use seasonal thermal energy storage and include a wood cook stove/oven. Our high end greenhouse has seasonal thermal energy storage with ~2600 feet of 4″ drain pipe for the heat exchanger and about 325 sealed HDPE drums filled with water to enhance the energy storage capacity and energy transfer rate. It will be instrumented. The greenhouse will use a blower for circulation, the house will be closed loop and convective. Energy prices are going to go up rapidly. The earth sheltered house will have the cost paid by the energy savings!