This map shows the amount of solar energy in hours, received
each day on an optimally tilted surface during the worst
month of the year.
(Based on accumulated worldwide solar insolation data.)
US Solar Insolation Map (Wrost Case - January)
This map shows the amount of solar energy in hours, received each day on an
optimally tilted surface during the worst month of the year for the United
States of America. Source: NREL.
