The report attributes the large dip in part to the economic slowdown. Californians drove fewer miles and used less energy in those tough years.
At the same time, California saw an 11 percent increase in renewable energy generation from 2009 to 2010.
Next10 founder Noel Perry says forward-looking state policies and private investment in renewables have spurred the positive changes.
PERRY: "From 2010 to 2011, clean tech investment in California rose by 24 percent to reach $3.5 billion."