A particularly attractive use of insulating panels is to have them double as reflectors—during the day they bounce additional energy through the same window they will insulate at night. Often it is most cost-effective to have a movable reflector outside a south window or skylight that is changed seasonally... not daily.

[O]ur next concern in heating the building is what keeps the earth warm..? What supplies the United States with the energy to maintain an average temperature of 60 degrees Fahrenheit as it spins in empty space at absolute zero? This is a heating contract that no oil company would be quick to try and fill.

I want to build buildings and design systems that are beautiful and simple and that really work. ...It’s not ...exotic or earthshaking to fill 55-gallon drums with water, paint them black and place them in the walls of a home for use as solar collectors ...but it works.