While 2009 saw only modest growth for new installations, the pipeline of contemplated projects expanded dramatically, according to the latest quarterly report from the California Public Utilities Commission.

Under the state's RPS, electricity providers must add renewable resources equal to 1% of their retail sales annually until they reach 20%, no later than 2010. California is currently drafting rules for a further renewable mandate of 33% by 2020, the most ambitious in the US.

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