(96a) Session Keynote - Integration, Control, and Optimization of Hydrogen Energy Storage in Utility Grid Networks

Brouwer, J. - Presenter, University of California, Irvine
Global warming, air pollution, and energy security concerns are evolving the way energy is delivered and converted over the next century with huge increases in the levels of clean and renewable energy while reducing energy demand in all economic sectors. Renewable power is the first and foremost option for decarbonizing electricity generation since it is abundant, sustainable, has lesser emissions and environmental impacts, and is widely available globally. It has been shown that multiple combinations of renewable resources including solar, wind, geothermal, hydropower, and biopower are capable of meeting 80% of total U.S. electricity demand in 2050 while achieving deep reductions in electric sector emissions. However, greater levels of renewable power use pose new challenges to electric grids due to geographical dependency, transmission constraints and most importantly power output variability. Therefore, increasing penetrations of renewable power must be accompanied by higher flexibility in the electricity grid through a portfolio of supply- and demand- side technologies, including energy storage, transmission and distribution infrastructure expansion, more highly responsive loads, and enhanced power system operation.

A compressed hydrogen energy storage system, comprised of an electrolyzer that produces hydrogen from water by using otherwise curtailed renewable electricity, and a fuel cell that utilizes the hydrogen to provide power to the grid, has been considered less favorable than batteries due to lower round-trip efficiency and relatively high cost. However, for integration with large-scale wind energy, accomplishing massive energy storage, and for storing over long periods of time (e.g., seasonal), large energy capacity and low self-discharge become more important than round trip efficiency; therefore such hydrogen energy storage systems become more attractive.

A dynamic model to simulate the integration of hydrogen energy storage systems in utility grid networks has been developed to evaluate the potential of hydrogen energy storage in mitigating the impacts of intermittent renewable power on the grid. A reduction in the renewable energy curtailed and the ramping events has been observed under the application of different hydrogen production, storage and power supply strategies. Data from the state of California has been used as a reference for energy consumption and power generation, assuming the evolution of the power market towards the fulfillment of goals set by the different policies and laws of the state. It was found that both diurnal and seasonal load shifting are possible with gaseous storage facilities that are already available and in use for natural gas storage in the state. Moreover, with the optimal management of the storage facilities, it is viable to dispatch the compressed hydrogen, supplying a significant amount of fuel for transportation applications and averting the need for installing additional electrical transmission and distribution equipment.