Clean Energy Systems Inc. has raised about $14 million from investors to develop a steam generator for a clean-burning power plant capable of producing enough electricity for 50,000 homes. Two Canadian companies have invested a total of $13 million, while the Southern California Gas Co. has put in $1 million. The generator, developed by former Aerojet engineers, burns natural gas and shoots out steam that turn power turbines. The generator emits only water and carbon dioxide, and does not need a smokestack. The first power plant built with the steam generator is a 5-megawatt plant near Bakersfield. Now, Clean Energy is looking to build a 50-megawatt plant, but first needs a commitment from a utility company to buy the power.