The State of California has mandated that 33% of all electricity come from renewable sources by 2020. This highly ambitious plan, while laudable, creates multiple challenges for it to be implemented.
A 2009 report from the California Public Utilities Commission (CPUC) details the daunting tasks ahead. 33% renewables by 2020 will entail 75 TWh of new renewable energy in addition to the existing 27 TWh already installed. In addition, 12 new transmission lines costing $12 billion will need to be built. They also say that regardless of what happens, electricity in 2020 will be more costly than it is now and suggest that mitigation strategies be developed in case some of the developments falter. These strategies include planning for more transmission and generation than 33%, building renewable energy plants on pre-permitted land, and encouraging the use of rooftop solar, which is not dependent upon new transmission lines.
One of their primary concerns in the report, and one they keep returning to, is the need for new transmission lines. Building huge wind and solar farms in rural areas, which in California are usually located in deserts, is of little good if the power can't get to the cities. Thus, major new transmission lines are needed, as well as a grid that can handle sudden fluctuations in energy production when the wind starts and stops, or if the sun goes behind a cloud momentarily. In the enthusiasm for renewable energy, the need for transmission lines tends to be overlooked, but is crucial.
Another challenge is the permitting process. Getting final approval to build a new wind or solar farm can take years, especially if local NIMBYs are well-organized and well-financed. This is equally true, maybe more so, of new transmission lines. Most people don't want to look at them. Plus, environmental impact statements must be filed and then approved by any number of regulatory agencies.
But the biggest challenge is whether California can actually install that much renewable energy by 2020. The CPUC has launched two programs to encourage the use of renewable. The California Solar Initiative provides rebates and incentives totaling over $2 billion for ten years to state utilities to build solar. The New Solar Home partnership provides incentives for rooftop solar. Between them, they hope to create 2.3 GW of new solar energy by 2017 (assuming everything gets built on time and NIMBYs don't successfully block projects with lawsuits).
While 2.3 GW of new renewable power will certainly be quite an accomplishment, it falls short of what is needed. While many other projects are being built too, it's still difficult to see how the 33% goal can be reached on time. The California Independent System Operator tracks energy production in California. Their renewables watch report for June 27, 2011(PDF) is typical and sobering. Renewable energy production was about 12.5%. California has a long way to go and a short time to get there, especially considering the hurdles it faces, in creating 33% renewables by 2020.