This line shapefile contains tilted photovoltaic solar power resource levels of watt hours per meter squared (Wh/m2) in the contiguous United States using 50-meter interval contour lines. Tilted photovoltaic panels are those that are angled in order to maximize exposure to direct sunlight. Tilt angles are often equal to the site's latitude but may vary throughout the year. This layer is a part of a collection of GIS data containing renewable and electric energy information for the U.S., including data on transmission lines, power plants and electricity substations.This layer can be used for estimates of solar resource potential.