Description : What is used at the Solar One facility in California to concentrate the sun and sun rays?
Last Answer : Heliostats, movable mirrors, were used to concentrate the sun'srays on a central tower of initially water, and later, salt.Solar One and Solar Two were test sites, and neither operatesanymore. The ... during 15 hours ofdarkness. During the summer of 2013 the plant ran 24/7 for 36consecutive days.