Using the Google Earth file, one can easily determine the optimum tilt and azimuth angles for any site in California, as well as the average annual increase in radiation at the optimum tilt and azimuth versus horizontally flat. These maps were created using the SUNY 10km Gridded Dataset and an algorithm described by J. Page (in Practical Handbook of Photovoltaics: Fundamentals and Applications) for transforming horizontal global and diffuse radiation into radiation on an inclined surface.
California Maps in Google Earth
USA Maps in Google Earth
by Matt Lave