Energy Systems and Infrastructure Analysis Division, Argonne National Laboratory, Lemont, Illinois 60439, United States.
Office of Nuclear Energy, U.S. Department of Energy, Washington, District of Columbia 20585, United States.
Environ Sci Technol. 2024 Oct 22;58(42):18654-18662. doi: 10.1021/acs.est.3c06769. Epub 2024 Oct 7.
Recent concerns surrounding climate change and the contribution of fossil fuels to greenhouse gas (GHG) emissions have sparked interest and advancements in renewable energy sources including wind, solar, and hydroelectricity. These energy sources, often referred to as "clean energy", generate no operational onsite GHG emissions. They also offer the potential for clean hydrogen production through water electrolysis, presenting a viable solution to create an environmentally friendly alternative energy carrier with the potential to decarbonize industrial processes reliant on hydrogen. To conduct a full life cycle analysis, it is crucial to account for the embodied emissions associated with renewable and nuclear power generation plants as they can significantly impact the GHG emissions linked to hydrogen production and its derived products. In this work, we conducted a comprehensive analysis of the embodied emissions associated with solar photovoltaic (PV), wind, hydro, and nuclear electricity. We investigated the implications of including plant-embodied emissions in the overall emission estimates of electrolysis hydrogen production and subsequently on the production of synthetic ammonia, methanol, and Fischer-Tropsch (FT) fuels. Results show that average embodied GHG emissions of solar PV, wind, hydro, and nuclear electricity generation in the United States (U.S.) were estimated to be 37, 9.8, 7.2, and 0.3 g CO e/kWh, respectively. Life cycle GHG emissions of electrolytic hydrogen produced from solar PV, wind, and hydroelectricity were estimated as 2.1, 0.6, and 0.4 kg of CO e/kg of H, respectively, in contrast to the zero-emissions often used when the embodied emissions in their construction were excluded. Average life cycle emission estimates (CO e/kg) of synthetic ammonia, methanol, and FT-fuel from solar PV electricity are increased by 5.5, 16, and 49 times, respectively, compared to the case when embodied emissions are excluded. This change also depends on the local irradiance for solar power, which can result in a further increase of GHG emissions by 35-41% in areas of low irradiance or reduce GHG emissions by 21-25% in areas with higher irradiance.
最近，人们对气候变化以及化石燃料对温室气体（GHG）排放的贡献表示担忧，这激发了对风能、太阳能和水电等可再生能源的兴趣和发展。这些能源通常被称为“清洁能源”，在运行过程中不会产生温室气体排放。它们还可以通过水电解生产清洁氢气，为创造一种环保的替代能源载体提供了可行的解决方案，该载体有可能使依赖氢气的工业过程脱碳。为了进行全面的生命周期分析，必须考虑到可再生能源和核能发电厂的隐含排放，因为它们会显著影响与氢气生产及其衍生产品相关的温室气体排放。在这项工作中，我们对太阳能光伏（PV）、风能、水能和核能的隐含排放进行了全面分析。我们研究了在电解氢气生产的总体排放估算中纳入工厂隐含排放的影响，以及对合成氨、甲醇和费托（FT）燃料生产的影响。结果表明，美国太阳能光伏、风能、水能和核能的平均隐含 GHG 排放量分别估计为 37、9.8、7.2 和 0.3 g CO e/kWh。从太阳能光伏、风能和水电生产的电解氢气的生命周期 GHG 排放量分别估计为 2.1、0.6 和 0.4 kg CO e/kg H，而在排除其建设中的隐含排放时，通常使用的是零排放。与排除隐含排放的情况相比，太阳能电力生产的合成氨、甲醇和 FT 燃料的平均生命周期排放估算值（CO e/kg）分别增加了 5.5、16 和 49 倍。这种变化还取决于太阳能的当地辐照度，在辐照度较低的地区，温室气体排放量可能会增加 35-41%，而在辐照度较高的地区，温室气体排放量可能会减少 21-25%。
