New wind-generation is the easiest to install, but because of it’s intermittent nature, “presents the largest operational challenges,” according to a November 30 California Independent System Operator report. Hydropower, geothermal, and biomass, are more predictable, said the engineering staff report. Concentrated solar is so small of a resource, it added, that, “it doesn’t present significant integration issues.” The grid operator staff focused on the potential for 4,000 MW of new wind power from the Tehachapi Mountains. That power could be transmitted to Southern California Edison’s service territory–and the utility has plans to build lines to do so. However, the grid operator noted that it’s not just a factor of the amount of power, but that the intermittent nature of wind generation also requires voltage support. According to the report, existing wind turbines in the area do not have the voltage support required by the Western Electricity Coordinating Council. The staff report calls this lack of voltage support “unacceptable.” “Wind turbine technology has improved considerably since the deployment of most turbines in Tehachapi, so this will not be an issue in the future,” according to Nancy Rader, California Wind Energy Association executive director. She added that the Federal Energy Regulatory Commission has strict voltage requirements for wind turbines on the grid. Rader noted that the organization was pleased that CAISO did the study with “realistic assumptions.” However, she said it was missing a wind-solar synergy investigation, among other things.