A recent study performed for California's five major utilities by the research firm Energy and Environmental Economics (E3) provides a roadmap for achieving 50% renewable energy by 2030 in the state with a relatively modest 2% impact on rates, or less, according to an analysis of the report by the California Wind Energy Association (CalWEA). Currently, California has a 33% by 2020 renewable portfolio standard.
The E3 report estimated the system average rate impact of a 50% solar-heavy renewables scenario at 14% in 2030. A more diverse E3 renewables scenario dropped that figure to 9%. However, CalWEA claims that its further analysis reveals that the E3 study did not fully utilize its sound methodological framework to develop a cost-effective mix of renewable resources and system-integration mitigation measures for a 50% renewable energy future.
According to CalWEA, it is possible to dramatically reduce total overall costs by applying the low-cost mitigation measures identified by E3 to a renewable resource mix with lower total costs (including both procurement and integration costs). The result was a 2% rate impact in 2030.
"E3's model not only accounts for the variation in the many factors that influence system operations and costs under a high penetration of renewables, but it reduces integration issues and costs to a single "common currency,'" says Dariush Shirmohammadi, CalWEA's transmission advisor. "This common currency readily enables these impacts, and the mitigation measures to be directly and objectively compared under various scenarios and assumptions."
CalWEA Executive Director Nancy Rader adds that "while many important policy and institutional changes will certainly be necessary to achieve 50 percent renewables, it is encouraging that E3's study shows that this goal is affordable and technically achievable."