Based on the sun index level, Nebraska is ranked thirteenth among the states with the greatest energy potential from solar power, according to a sun index developed for the National Renewable Energy Laboratory (NREL) using data provided by NREL's Renewable Resource Data Center.
The sun index is defined as an index of the amount of direct sunlight received in each state and accounts for latitude and cloud cover. California is indexed at 1.0. The amount of direct sunlight was derived from numbers provided by the Renewable Resource Data Center. The sun index was calculated as the average number of hours of peak direct sunlight hours per year from 1960 to 1990.