Environmentally friendly gadgets big, like the Chevy Volt, to smaller, like the Big Belly solar trash compactor are on display.

ERNEST MONIZ: "This unit will crush five times as much as a normal trash bin."

Ernest Moniz offers his pitch on a greener trash can. 

ERNEST MONIZ: "Instead of having a trash bin which is collected in a city daily, this you can collect five to seven days. There are over a thousand units in California already, since 2007."

It's all part of the Green California Summit and Expo. The event brings together the green tech sector and representatives from the government sector. And with new green building codes and laws mandating carbon reduction on the books, it's a growing event.

This year more than 5,000 people are expected to pass through the two day event which ends Wednesday.