It seems like common sense: Solar panels in the northern hemisphere should face south in order to soak up maximum sunlight. In this case, common sense might be wrong.
A recent report from the Pecan Street Research Institute found that rooftop solar panels facing west actually generate 49% more energy during peak demand periods (the times of day when the power grid is most strained) than south-facing solar panels. At the same time, south-facing panels cut peak demand on the grid by just 54%, while west-facing panels cut demand by 65%.
Pecan Street’s data comes from a survey of 50 single-family homes in Austin, Texas. Almost half of all homes surveyed had south-facing panels, and the rest had panels facing west or a combination of west and south. Perhaps utilities should provide incentives to rooftop solar owners to go with west-facing panels–it will benefit everyone in the end, as long as Pecan’s research holds up when it starts surveying homes in other states.