By Gillian Flaccus, Associated Press.

When most Californians think about the source of renewable energy flowing into their homes, they picture wind turbines and solar panels — not garbage.

The little-known source of electricity has flowed into California’s power grid for decades, but a groundbreaking Thursday for yet another trash-driven power project at a massive Orange County landfill could be one of the last on the books. With the evaporation of tax credits and grants and dropping natural gas prices, the waste pit near Irvine is one of the last in the nation that’s large enough to generate enough power to be profitable.