Scenarios for Offshore Wind Power Production for BOEM Central California Call Areas

Abstract:

Interest in offshore wind development in California is growing. In response, the Bureau of Ocean Energy Management (BOEM) has proposed priority areas for leasing, known as ‘call areas.’ To appropriately evaluate these call areas, an estimate of power production using prospective turbine technology in these areas is needed. This study provides an updated and comprehensive characterization of offshore wind power potential within the two Central California call areas (Diablo Canyon and Morro Bay) using hourly wind data from the WIND Toolkit. Potential power production is evaluated using12 and 15 MW turbines under different inter-turbine spacing and wind farm size scenarios. Our comparative analysis shows similar daily and seasonal patterns of wind power produced within the call areas, which peak in spring and during evening hours. The per-turbine power production is higher in the Morro Bay call area due to slightly higher hub-height wind speeds, whereas the total potential power production is higher in the Diablo Canyon call area due to its larger size. These similarities and differences hold true regardless of turbine type. Using inter-turbine spacing based on the rotor diameter reveals that overall per-unit-area power production is similar between 12 and 15 MW, due to a compensatory tradeoff between higher turbine rated power (15 MW) and higher inter-turbine spacing density (12 MW). We estimate that the combined power production from the two call areas, if they were to be fully built out, could produce up to 23% of California’s annual electrical energy production. A commercial-scale wind farm (960 MW) would occupy at least 25% of the Morro Bay call area and 14% of the Diablo Canyon call area, respectively. These results provide guidance on offshore wind development over the Central California Coast, and the framework demonstrated here could be applied to other wind data sets in other regions to assess potential power production. Moreover, results could be integrated with studies on economic, cultural, and environmental factors to optimize wind farm siting.