U.S. houses are more energy efficient ... or are they? In this video, Tyler Crowe explains how modern houses are more energy efficient on a square foot basis, but since newer houses are bigger, they consume more energy on a per home basis. Utility companies will not be hurt by this trend. However, how utilities generate electricity is important.  NRG Energy (NRG -0.20%) and TransCanada are better-positioned to exploit cheap natural gas than Exelon (EXC 0.27%) or Duke (DUK 0.48%).  Also, new EPA regulations may significantly impact utilities that rely on coal or nuclear for electricity generation.