Our Solar Value Index is an indicator of the annual economic value of solar power. It's computed by multiplying the average utility rate in a state with the annual expected solar production from an average-sized (5 kW) residential solar photovoltaic system. The table below includes the top 100 biggest U.S. cities by population. Learn more.
Average utility rates in each state are published by the Energy Information Administration on a monthly basis. However, due to seasonal effects and other factors, month-to-month rates can change significantly. In order to account for this natural variation, we take a rolling-average of 12 months and use this figure as the average utility rate. The population data is provided by the United States Census Bureau (2014 figures).
Solar energy production is determined by many factors such as latitude, local climate and elevation. We provide the expected solar production values (in kWh) for an average-sized residential system with 5 kW installed capacity in the table below. These figures are based on the models and data from the National Renewable Energy Laboratory. Learn more.