An Assessment of Battery and Hydrogen Energy Storage Systems Integrated with Wind Energy Resources in California

This exploratory investigation examined energy storage technologies that can potentially enhance the operation of wind power and other intermittent renewable energy systems. The authors conducted economic and environmental analyses of four energy storage options: (1) lead acid batteries, (2) zinc bromine (flow) batteries, (3) a hydrogen electrolyzer and fuel cell storage system, and (4) a hydrogen storage option where the hydrogen was used for fueling hydrogen powered vehicles. These were considered under two wind penetration scenarios (2010 and 2020) at four California sites that are likely to experience significant wind farm development. Analysis with NREL’s HOMER model showed that, in most cases, energy storage systems were not well utilized until higher levels of wind penetration were modeled (i.e., 18% penetration in Southern California in 2020). In the scenarios, hydrogen storage became more cost-effective than battery storage at higher levels of wind power production, and using the hydrogen to refuel vehicles was more economically attractive than reconverting the hydrogen to electricity. The overall value proposition for energy storage used in conjunction with intermittent renewable power sources depends on multiple factors. The initial qualitative assessment found the various energy storage systems to be environmentally benign, except for emissions from the manufacture of some battery materials.