Wohlfahrt Georg, Tomelleri Enrico, Hammerle Albin
University of Innsbruck, Department of Ecology, Innsbruck, AUSTRIA.
Free University of Bolzano, Faculty of Science and Technology, Bolzano/Bozen, ITALY.
Nat Energy. 2021 Apr;6(4):372-377. doi: 10.1038/s41560-021-00784-y. Epub 2021 Feb 25.
Hydropower emits less carbon dioxide than fossil fuels but the lower albedo of hydropower reservoirs compared to terrestrial landscapes results in a positive radiative forcing offsetting some of the negative radiative forcing by hydroelectricity generation. The cumulative effect of this lower albedo has not been quantified. Here we show, by quantifying the difference in remotely sensed albedo between globally distributed hydropower reservoirs and their surrounding landscape, that 19 % of all investigated hydropower plants required 40 years and more for the negative radiative forcing from the fossil fuel displacement to offset the albedo effect. The length of these break-even times depends on the specific combination of climatic and environmental constraints, power plant design characteristics and country-specific electricity carbon intensities. We conclude that future hydropower plants need to minimize the albedo penalty in order to make a meaningful contribution towards limiting global warming.
与化石燃料相比，水力发电排放的二氧化碳较少，但与陆地景观相比，水电水库的反照率较低，导致正辐射强迫，抵消了部分水电发电产生的负辐射强迫。这种较低反照率的累积效应尚未得到量化。在此，我们通过量化全球分布的水电水库与其周边景观之间遥感反照率的差异表明，在所有调查的水电站中，19%需要40年或更长时间，化石燃料替代产生的负辐射强迫才能抵消反照率效应。这些收支平衡时间的长短取决于气候和环境限制、电厂设计特征以及特定国家的电力碳强度的具体组合。我们得出结论，未来的水电站需要尽量减少反照率损失，以便为限制全球变暖做出有意义的贡献。
