Hydroelectricity provides 6% of U.S. electrical power needs, but hydro-dams block migrations of both anadromous and catadromous fishes. Engineered fishways have been built to facilitate fish movements past dams, but many have performed poorly. Dam removal is an effective way of restoring dwindling migratory fish populations by allowing unrestricted pathways to their spawning areas and for the downstream migrations of post-spawning adults and juveniles. However, hydro-dam removals result in a loss of electricity production. For the replacement of energy foregone from a dam removal, various alternative energy installations are now feasible. Here, we present a one-to-one conceptual replacement of hydropower with photovoltaic (PV) outputs for large and small river systems in Maine. We estimate that the equivalent land area needed to replace 14 hydro-dams with PV panels in the Kennebec River watershed—producing an annual mean (±SE) of 1,101.7 ± 37.9 gigawatt-hours—is 950.7 ± 32.8 ha, which is equivalent to 22% of the existing reservoir area. For the Mousam River, three hydro-dams could be replaced with 0.38 ha of PV. Our results indicate that modest land areas are needed to replace hydroelectricity with PV from even heavily dammed rivers, providing a realistic and potentially highly effective conservation policy option for Maine and for elsewhere.

中文翻译：

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潜在的太阳能替代水电以重新开放河流：以缅因州为例

水力发电提供了美国 6% 的电力需求，但水坝阻止溯河和溯河鱼类的洄游。已经建造了工程鱼道以促进鱼类通过大坝的运动，但许多鱼道表现不佳。大坝拆除是恢复不断减少的洄游鱼类种群的有效方法，它允许不受限制的通道进入它们的产卵区以及产卵后的成鱼和幼鱼的下游洄游。然而，水坝拆除会导致电力生产损失。为了替代因拆除大坝而放弃的能源，各种替代能源装置现在都是可行的。在这里，我们提出了缅因州大小河流系统的水电与光伏 (PV) 输出的一对一概念替代。我们估计，在肯尼贝克河流域用光伏电池板替换 14 个水坝所需的等效土地面积——年平均 (±SE) 为 1,101.7 ± 37.9 吉瓦时——为 950.7 ± 32.8 公顷，相当于 22现有库区的百分比。对于穆萨姆河，三座水坝可以用 0.38 公顷的光伏发电代替。我们的研究结果表明，需要适度的土地面积来用来自甚至严重筑坝的河流的光伏发电取代水电，从而为缅因州和其他地方提供了一个现实且潜在高效的保护政策选择。