California's aggressive energy rules require its utilities to hit an ambitious target: 20 percent of their electricity should come from renewable sources by the end of this year. They're not going to make it. But because of the drive for renewables, they are close to building some of the biggest solar power projects in the country—including one that would be the biggest ever. The Beacon Solar Energy Project received the seal of approval from the California Energy Commission (CEC) this week. Beacon will be a 250-megawatt plant built north of Los Angeles near Mojave, California, and would cover more than 2,000 acres. Beacon is solar thermal: Rather than converting sunlight to electricity through photovoltaic cells, solar thermal projects use mirrors to concentrate the heat of the sun, creating steam to turn turbines.