This requires a cite. California imports 10% from the northwest (the bulk of that is hydro), and 20% from the southwest (of which
30% comes from coal). The remaining 70% is generated in-state. Note that the drought has increased the draw from out-of-state due to a 36% drop in in-state hydro in 2012 and a further 10% drop in 2013. The shutdown of San Onofre has also increased imports.