By Scott DiSavino March 15 (Reuters) - Power generating companies built fewer power plants in the United States during the first two months of 2013 than in the first two months of 2012, U.S. energy regulators said in a report. Generating companies completed 57 units so far in 2013 with a capacity of 1,584 megawatts (MW), versus 99 units in the first two months of 2012 with a capacity of 3,145 MW, the U.S. Federal Energy Regulatory Commission (FERC) said in a report Thursday. One megawatt powers about 1,000 homes. Most of the new generation in 2013 was wind power with 958 MW installed, followed by solar with 424 MW and natural gas at 170 MW. In 2012, the biggest new source of generation in the first two months was also wind with 1,051 MW, followed by natural gas at 1,028 MW and coal at 808 MW. The biggest unit FERC highlighted in its report was Exelon Corp's 100-MW Antelope Valley Solar Ranch One in California. FERC said the power from Antelope Valley will be sold to PG&E Corp's Pacific Gas & Electric unit in California. FERC said the 130-MW phase two of Antelope Valley was expected to be completed by the end of 2013. On the transmission front, FERC pointed to three projects. Construction has started on the $500 million, 150-mile (241 km) Hampton-Rochester-La Crosse 161- and 345-kilovolt (kV) transmission project in Minnesota and Wisconsin, which is expected to enter service in 2015. Kansas City Power & Light (KCP&L) and Omaha Public Power District plan to build a $400 million, 190-mile, 345-kV line from Sibley, Missouri to Nebraska City, Nebraska, which is expected to enter service by June 2017. KCP&L is a unit of Great Plains Energy Inc. PPL Corp said it planned to invest $968 million in infrastructure improvements in 2013, including $352 million in distribution and $616 million for transmission. The PPL transmission projects include its part of the 146-mile, 500-kV Susquehanna-Roseland line that is expected to enter service in 2015. The project, which includes a unit of Public Service Enterprise Group Inc, will connect Berwick, Pennsylvania, to Roseland, New Jersey and will cost a total of $1.2 billion.