payback

Going Green

Passivhaus Design

It started off as a super-energy-efficient residential design standard in Germany. Passivhaus Design is an extremely tight building standard, minimizing outside air infiltration at every possible opportunity.  Less outside air entering a structure means the […]
Going Green

Solar Water Heating

In the past, solar energy has been prohibitively expensive, with payback over 20 years for most applications. Photovoltaics are still quite expensive, while parabolic collectors and other concentrating means are not much better. The machinery […]