This is a very easy question to answer: as this Los Angeles Times article points out, there are no enforcement provisions in the 20% renewable energy 2010 law.
The article also mentions: “The utilities say they’ve been hampered by delays in getting transmission lines licensed and built in California so they can bring wind, solar and geothermal power from remote desert and mountain areas to population centers along the coast.”
Renewable energies are every day gaining more space on developed countrys. The 20% level maybe it couldnt be reached, but its rising at least.
Of course the 20% level will not be achieved in time. Whilst there is no economic incentive for it happen, it won’t.