Using current technological prowess to get to the 100% renewable goal using solar and wind and using current outputs and footprints as our guide then:
-16K square miles of wind turbines will be needed to reach stated goal for wind output
-Approximately 500 square miles of solar energy panels to reach stated goal for solar output
In essence to meet stated goals, California will have to produce more renewable energy by 2048 than the entire world produces now. Using known technology, the environmental costs in land use alone will be astronomical, not even taking into all the other environmental impacts.