For the record - Sept. 20, 2007

Energy sources: An editorial Monday on renewable energy said that costs for solar panels remain high because the world is running out of silicon. In fact, there is a shortage of polysilicon, a manufactured material of which silicon is the basic component. The editorial also said that a “100-square-mile” area of Nevada, if equipped with solar devices, could meet all of the United States’ power needs. It should have said a “100-mile-square” area.