Calpine says in a press release for the Metcalf Energy Center at http://www.southsanjose.com/calpower.htm:

"This facility will help limit power interruptions that create inconvenience for local residents and productivity losses for employers."

The California Energy Commission says on page 29 of The 1996 Electricity Report at http://www.energy.ca.gov/ER96/index.html:

"Most power outages are caused by distribution system failures, not by problems originating with the generation or bulk transmission systems."

From page 5 of The 1996 Electricity Report:

"Transmission -- Carrying the power from power plants over high-voltage transmission lines to load centers."

"Distribution -- Delivering the power to customers at reduced voltages, through substations and distribution lines."

My reading of The 1996 Electricity Report says most of our power outages are caused by local problems in the low voltage power lines so having a neighborhood power plant is not going to do much to improve reliability.