Hydropower plans in eastern and southern Africa increase risk of concurrent climate-related electricity supply disruption

Hydropower comprises a significant and rapidly expanding proportion of electricity production in eastern and southern Africa. In both regions, hydropower is exposed to high levels of climate variability and regional climate linkages are strong, yet an understanding of spatial interdependences is lacking. Here we consider river basin configuration and define regions of coherent rainfall variability using cluster analysis to illustrate exposure to the risk of hydropower supply disruption of current (2015) and planned (2030) hydropower sites. Assuming completion of the dams planned, hydropower will become increasingly concentrated in the Nile (from 62% to 82% of total regional capacity) and Zambezi (from 73% to 85%) basins. By 2030, 70% and 59% of total hydropower capacity will be located in one cluster of rainfall variability in eastern and southern Africa, respectively, increasing the risk of concurrent climate-related electricity supply disruption in each region. Linking of nascent regional electricity sharing mechanisms could mitigate intraregional risk, although these mechanisms face considerable political and infrastructural challenges.

水电在东非和南非的电力生产中所占比例重大且增长迅速。在这两个地区，水电都面临着高度的气候变化，区域气候关联性很强，但缺乏对空间相互依存关系的了解。在此，我们考虑河流流域的配置，并使用聚类分析来确定降雨变化一致的区域，以说明当前（2015年）和规划（2030年）的水电站点面临的水电供应中断风险。假设规划中的水坝建成，水电将越来越集中在尼罗河流域（从占区域总容量的62%增长到82%）和赞比西河流域（从73%增长到85%）。到2030年，东非和南非分别将有70%和59%的水电总容量位于一个降雨变化集群内，这增加了每个地区同时出现与气候相关的电力供应中断的风险。将新生的区域电力共享机制连接起来可以减轻区域内的风险，尽管这些机制面临着相当大的政治和基础设施挑战。