Olaitan Damola, Bertagni Matteo, Porporato Amilcare
Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ 08540, USA.
Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ 08540, USA; The High Meadows Environmental Institute, Princeton University, Princeton, NJ 08540, USA.
Sci Total Environ. 2024 Jun 1;927:172384. doi: 10.1016/j.scitotenv.2024.172384. Epub 2024 Apr 10.
Hydrogen (H) is the most promising energy carrier for reducing the carbon emissions of the energy sector, but the impact of its production on water resources remains unclear. Here, we quantify the water footprint (WF) of different H production pathways accounting for the WF of the primary energy used in the production process, as well as feedstock and infrastructure water requirements. Results suggest that green H obtained from water electrolysis powered by renewable energy has the lowest WF (65 ± 2 m/TJ for wind and 204 ± 79 m/TJ for solar) mostly due to the low WF of renewable energy. The WF of blue H derived from fossil fuels is significantly higher (369 ± 30 m/TJ for natural gas and 564 ± 82 m/TJ for coal) due to high WF of fossil fuels as well as the water required for carbon capture and storage (CCS). H produced from nuclear energy and biomass have extremely high WF (741 ± 277 m/TJ for nuclear and > 50,000 m/TJ for biomass). Considering global and country-based energy scenarios, where the main H colors (green and blue) individually account for 15 % of energy consumption, we find that the use of green H could reduce the water demand of the energy sector while blue H would generally increase it, except in countries already characterized by high water consumption due to reliance on water-intensive energy sources. At the global level, we find that for every 5 % of H energy adoption, the energy sector could have water savings between 1 and 4 % for green H and increase water consumption between 1 and 5 % for blue H. These results highlight the potential and criticalities of H within the water-energy nexus.
氢（H）是减少能源部门碳排放最具前景的能量载体，但其生产对水资源的影响仍不明确。在此，我们对不同制氢途径的水足迹（WF）进行了量化，其中考虑了生产过程中所用一次能源的水足迹，以及原料和基础设施的用水需求。结果表明，由可再生能源供电的水电解制得的绿色氢水足迹最低（风能制氢为65±2立方米/太焦耳，太阳能制氢为204±79立方米/太焦耳），这主要归因于可再生能源的低水足迹。源自化石燃料的蓝色氢水足迹显著更高（天然气制氢为369±30立方米/太焦耳，煤炭制氢为564±82立方米/太焦耳），这是由于化石燃料的高水足迹以及碳捕获与封存（CCS）所需的水。核能和生物质制氢的水足迹极高（核能制氢为741±277立方米/太焦耳，生物质制氢大于50,000立方米/太焦耳）。考虑到全球和基于国家的能源情景，其中主要的氢颜色（绿色和蓝色）分别占能源消耗的15%，我们发现使用绿色氢可以减少能源部门的用水需求，而蓝色氢通常会增加用水需求，但依赖高耗水能源且已具有高用水量特征的国家除外。在全球层面，我们发现每采用5%的氢能源，对于绿色氢，能源部门的节水量可达1%至4%；对于蓝色氢，用水量会增加1%至5%。这些结果凸显了氢在水 - 能源关系中的潜力和关键作用。
