Air Emissions and Health Impacts of Two Hydrogen-Based Electricity Generation Methods

Electricity production using fossil fuels contributes to air pollution and adverse health impacts. One option for decreasing fossil fuel consumption is replacing fossil fuel power plants with electricity produced from green hydrogen (H2, produced from renewable sources). Previous studies mainly focused on greenhouse gas emissions from two common H2 production methods, steam methane reforming (SMR) and water electrolysis. This study compares the estimated emissions and associated health outcomes of generating electricity from fossil fuels with electricity generated from H2 produced through SMR or electrolysis in various regions of the United States. Shifting from coal-generated electricity to SMR-produced H2-generated electricity results in health benefits while shifting from natural gas-generated electricity to electricity generated from H2 generated via water electricity results in health costs in all regions. Depending on the region, replacing a natural gas power plant with electricity generated from H2 produced via SMR or replacing a coal power plant with electricity generated from water electrolysis could result in either health benefits or costs. This study also considers the impact of plant location on human health outcomes as well as the impact of increasing renewable energy percentages on health outcomes associated with replacing a coal or natural gas power plant with electricity generated from H2 produced through grid-based water electrolysis. The results indicate that a high renewable fraction (over 85% of the grid) is required to experience health benefits, emphasizing the challenges associated with moving toward electrolysis-based H2 production for electricity generation.