In the past, most home solar installations have been placed facing the south. This was based on the calculation that the panels receive the most sun overall throughout the day when oriented in that direction. However, several recent studies indicate that we may have been orienting our solar panels in the wrong direction for environmental efficiency all along. West-facing panels are now considered to be the better choice for home solar production.
This shift in ideas was brought on by the realization that solar panels were not providing the majority of their energy during the hours of the day when it was most needed. Southern-facing panels generate the majority of their energy at midday, when the sun is highest, but this is actually the time of least demand, since many people work during the day and leave the lights off in their homes. The more effective time for solar panels to draw their maximum amount of energy is during the peak after-work hours, when people come home, turn on their lights and entertainment systems, and cook meals. West-facing panels produce 49 percent more electricity than south-facing ones during these peak hours, according to a study by the Pecan Street Research Institute.
Utility companies are beginning to implement changes in their compensation programs for solar panel owners in accordance with these new findings. Previously, owners of solar panels were paid a flat rate for each unit of energy throughout the day, but now some companies are considering paying according to demand or offering bonus rebates for installation of west-facing panels.