Utility giant FPL has filed plans with California regulators to build a $1 billion, 250-megawatt solar power plant in the Mojave Desert. The move marks the first time that a major player — in this case a Fortune 500 company — has jumped into the nascent Big Solar market.

Juno Beach, Fla.-based FPL’s renewable energy arm, FPL (FPL)Energy, will operate the Beacon Solar Energy Project, which will connect to the transmission system operated by Los Angeles’ municipal utility, the Los Angeles Department of Water and Power. California law requires the state’s investor-owned utilities — PG&E (PCG), Southern California Edison (EIX) and San Diego Gas & Electric (SRE) — to obtain 20 percent of their electricity from renewable sources by 2010 and 33 percent by 2020. But public utilities like LADWP only have to set green energy targets, 13 percent by 2010 and 20 percent by 2017 in Los Angeles’ case. Under California’s global warming law, the state’s greenhouse gas emissions must be reduced to 1990 levels by 2020.