Forget about politically trendy liberals being influenced by their green credentials. The the single most important factor driving whether people instal solar is peer influence. That, at least, is what two researchers at Yale and the University of Connecticut have discovered. Their recently published paper Spatial patterns of solar photovoltaic system adoption: the influence of neighbors and the built environmentsays empirical estimation demonstrates a strong relationship between solar adoption and the number of nearby previously installed systems as well as built environment and policy variables.
“People have called it green envy before, where you want to be green so that you can show off your greenness effectively,” says Yale’s Kenneth Gillingham, a professor at the School of Forestry and one of the study authors. From an interview with the Washington Post:
In addition to initiatives like the Solarize program, Gillingham says the research suggests that it can be very important for houses who have just installed solar panels to let the installer put up a yard sign, especially if the installation is on the back of the house. “A common technique is to put a big sign in the front yard saying, ‘This house went solar,'” says Gillingham. That then rubs off on neighbors, proving that while there may be many good economic and policy reasons to support clean energy, in the end, humans are also social animals, and motivated by peer and group effects.
“You want to conserve, and be environmental, but you want to do it in a conspicuous way,” says Gillingham.