(111e) Renewable Hydrogen & Methane Production – Integration, Optimization and Cost Improvements

The move to renewable electricity sources is happening on a global scale to decarbonize the electricity sector. In a growing number of states and regions of the world, inherently variable renewable electricity sources continue to grow, but can be curtailed significantly when production outpaces demand. While MW-scale batteries do a good job of storing some of this electricity for hours to days and have a high roundtrip efficiency, storing this energy in molecular form (e.g., hydrogen or methane) provides a long-duration energy storage solution with essentially endless capacity. And in the case of renewable methane, the existing infrastructure can store terawatt-hours of energy...today. If the hydrogen is produced using renewable electricity and, in the case of methane, recycled carbon dioxide (CO2), renewable energy storage solutions become a sustainable and near-term solution that enable future expansion of electricity sources generated by solar and wind. Working closely with the Department of Energy’s Fuel Cell Technologies and Bioenergy Technology offices, industry partners and other stakeholders over the past 15 years, the National Renewable Energy Laboratory (NREL) has conducted research and development in improving the cost of integrating renewable electricity sources with hydrogen-producing low-temperature electrolyzers. Today, NREL operates an electrolyzer test facility capable of power electrolyzer stacks up to 1MW with compression and storage systems up to 900 bar. In addition, the integrated test facility is host to the first-of-its kind biomethanation system that use organisms to produce methane from recycled CO2 and the renewable hydrogen produced onsite at NREL. This presentation will summarize our work in the areas of integration with renewable electricity sources, power conversion, stack performance, balance of plant optimization and performance data from the biomethanation system.