More than 150 people gathered in Lancaster for the unveiling of the 5-megawatt thermal solar power plant that officials hope will kickstart the Antelope Valley as the clean energy capital of the state. The Sierra SunTower uses more than 20,000 mirrors controlled by sophisticated software to direct sunlight at boilers attached to large poles visible for miles around. The light turns water into steam to create enough electricity to power 4,000 homes. “We are ushering in the second Industrial revolution as we power the planet cost-effectively by the sun,” said Bill Gross, CEO of eSolar, the Pasadena-based company that funded and designed the plant. This demonstration site is meant to show that eSolar can commercialize its technology and produce solar power at a lower cost that can compete with that made from fossil fuels. The plant is just the first in the Antelope Valley to use eSolar’s technology. A 92-megawatt solar plant and a 245-megawatt plant will be built and operated by NRG Energy Inc. by 2012.