Existing resource base and policy decisions provide the West with electric fuel diversity
Coal, natural gas, and hydroelectric sources continue to contribute the majority of overall electricity generation in the West. However, a combination of aggressive state renewable portfolio standards, continued federal tax credits, grants, and other support has encouraged the increased use of non-hydro renewable sources of electricity generation (the green portion of the graphs above) in the West.
The West region consists of the entire Western Interconnection, where resources are generally shared and power flows are often directed toward California, which makes up 40% of the overall demand for electricity in the West region. It is common for electric utilities in California to own shares of or entire power plants (or to enter into long-term power purchase agreements with generators) that operate outside the state.
California imports a quarter of its electricity from the rest of the West, and the choices that California regulators make on which fuels to promote significantly influences the overall mix of fuels used in the region.
Generation from wind, solar, and other renewable sources has increased significantly in California over the past couple years. Additionally, several large-scale solar plants have come on line in Nevada and Arizona in recent years, adding more renewable capacity to the West region.
Output from nuclear units has been lower following the shutdown of the San Onofre Nuclear Generating Station (SONGS) in January 2012. Several new generators brought on line before summer 2013 helped the system deal with the loss of the 2,200-MW SONGS plant, which was crucially located in a load pocket, by providing voltage support and reactive power to the system.
The West region also holds the largest concentration of hydroelectric capacity in the nation. This capacity has a strong, seasonal effect on both the system's fuel mix throughout the year and the region's wholesale electric prices in the late spring, when the seasonal runoff typically occurs.
Principal contributor: M. Tyson Brown