Researchers in San Diego hung different messages on doors to see what would make people use less energy. The one that worked was telling people their neighbors were already doing it. A month later, those households had cut their energy use.
Behavioral science can be used to impact energy use decisions comes from a study that I did with some co workers in San Diego where we went door to door in certain neighborhoods and we put a door hanger, a different door hanger on houses and each door hanger said something different in an attempt to move them toward energy conservation for the month. A fourth sign that said merely the majority of your neighbors are undertaking efforts on a daily basis to reduce their energy consumption. That made a significant difference when we read their meters at the end of the month. Simply telling people what the social proof was, what the neighborhood norms were informed them about what they should do, and made a significant difference.