New York Times: Two California companies said Thursday that they would each build solar power plants that were 10 times larger than the largest now in service, creating the first true utility-scale use of a technology now mostly confined to rooftop supplements to conventional power supplies. The power will be sold to Pacific Gas and Electric, which is under a state mandate to get 20 percent of its electricity from renewable sources by 2010. The utility said that it expected the plants, both using …