Jeff Holland takes a picture of some of the 300,000 computer-controlled mirrors that reflect sunlight to boilers that sit on 459-foot towers Tuesday, Feb. 11, 2014 in Primm, Nev. (AP Photo/Chris Carlson) ( Worlds Largest Solar Plant )
A boilers sits on 459-foot towers vents steam Tuesday, Feb. 11, 2014 in Primm, Nev. The Ivanpah Solar Electric Generating System, sprawling across roughly 5 square miles of federal land near the California-Nevada border. (AP Photo/Chris Carlson) ( Worlds Largest Solar Plant )
Some of the 300,000 computer-controlled mirrors, each about 7 feet high and 10 feet wide, reflect sunlight to boilers that sit on 459-foot towers. The sun's power is used to heat water in the boilers' tubes and make steam, which in turn drives turbines to create electricity Tuesday, Feb. 11, 2014 in Primm, Nev. (AP Photo/Chris Carlson) ( Worlds Largest Solar Plant )
Jeff Holland, right, talks with Noel Hanson near a boilers that sit on 459-foot towers Tuesday, Feb. 11, 2014 in Primm, Nev. The Ivanpah Solar Electric Generating System, sprawling across roughly 5 square miles of federal land near the California-Nevada border. (AP Photo/Chris Carlson) ( Worlds Largest Solar Plant )
Some of the 300,000 computer-controlled mirrors, each about 7 feet high and 10 feet wide, reflect sunlight to boilers that sit on 459-foot towers. The sun's power is used to heat water in the boilers' tubes and make steam, which in turn drives turbines to create electricity Tuesday, Feb. 11, 2014 in Primm, Nev. (AP Photo/Chris Carlson) ( Worlds Largest Solar Plant )
Jeff Holland, right, talks with Noel Hanson near a boilers that sit on 459-foot towers Tuesday, Feb. 11, 2014 in Primm, Nev. The Ivanpah Solar Electric Generating System, sprawling across roughly 5 square miles of federal land near the California-Nevada border. (AP Photo/Chris Carlson) ( Worlds Largest Solar Plant )
A boilers sits on 459-foot towers vents steam Tuesday, Feb. 11, 2014 in Primm, Nev. The Ivanpah Solar Electric Generating System, sprawling across roughly 5 square miles of federal land near the California-Nevada border. (AP Photo/Chris Carlson) ( Worlds Largest Solar Plant )
Some of the 300,000 computer-controlled mirrors, each about 7 feet high and 10 feet wide, reflect sunlight to boilers that sit on 459-foot towers. The sun's power is used to heat water in the boilers' tubes and make steam, which in turn drives turbines to create electricity Tuesday, Feb. 11, 2014 in Primm, Nev. (AP Photo/Chris Carlson) ( Worlds Largest Solar Plant )
Workers monitor the 300,000 computer-controlled mirrors, each about 7 feet high and 10 feet wide, reflect sunlight into three boilers that sit on 459-foot towers. The sun's power is used to heat water in the boilers' tubes and make steam, which in turn drives turbines to create electricity Tuesday, Feb. 11, 2014 in Primm, Nev. (AP Photo/Chris Carlson) ( Worlds Largest Solar Plant )
Some of the 300,000 computer-controlled mirrors, each about 7 feet high and 10 feet wide, reflect sunlight to boilers that sit on 459-foot towers. The sun's power is used to heat water in the boilers' tubes and make steam, which in turn drives turbines to create electricity Tuesday, Feb. 11, 2014 in Primm, Nev. (AP Photo/Chris Carlson) ( Worlds Largest Solar Plant )
Some of the 300,000 computer-controlled mirrors, each about 7 feet high and 10 feet wide, reflect sunlight to boilers that sit on 459-foot towers. The sun's power is used to heat water in the boilers' tubes and make steam, which in turn drives turbines to create electricity Tuesday, Feb. 11, 2014 in Primm, Nev. (AP Photo/Chris Carlson) ( Worlds Largest Solar Plant )
Jeff Holland walks near some of 300,000 computer-controlled mirrors that reflect sunlight to boilers that sit on 459-foot towers Tuesday, Feb. 11, 2014 in Primm, Nev. (AP Photo/Chris Carlson) ( Worlds Largest Solar Plant )
Some of the 300,000 computer-controlled mirrors, each about 7 feet high and 10 feet wide, reflect sunlight to boilers that sit on 459-foot towers. The sun's power is used to heat water in the boilers' tubes and make steam, which in turn drives turbines to create electricity Tuesday, Feb. 11, 2014 in Primm, Nev. (AP Photo/Chris Carlson) ( Worlds Largest Solar Plant )
Some of the 300,000 computer-controlled mirrors, each about 7 feet high and 10 feet wide, reflect sunlight to boilers that sit on 459-foot towers. The sun's power is used to heat water in the boilers' tubes and make steam, which in turn drives turbines to create electricity Tuesday, Feb. 11, 2014 in Primm, Nev. (AP Photo/Chris Carlson) ( Worlds Largest Solar Plant )
A boilers that sit on 459-foot towers vents steam Tuesday, Feb. 11, 2014 in Primm, Nev. The Ivanpah Solar Electric Generating System, sprawling across roughly 5 square miles of federal land near the California-Nevada border. (AP Photo/Chris Carlson) ( Worlds Largest Solar Plant )