Environmental consequences of hydroelectric development: the role of facility size and type

The development of hydroelectric power throughout the world is receiving renewed attention as the economic, political, and environmental costs of conventional energy production rise. There is currently a perception that hydroelectricity has environmental and economic advantages over electricity produced by conventional energy technologies, but there is a paucity of information about the environmental impacts of hydroelectric facilities as a function of size and type. We characterize the environmental impacts of hydroelectric developments and quantify these impacts as a function of the size and type of project. Several unexpected conclusions arise from our analysis. For most hydroelectric facilities, size, as measured by installed capacity, is not necessarily a good indicator or the severity of environmental costs. For impacts such as land flooded and evaporative water lost, smaller facilities cause greater environmental disruptions per unit of energy produced than do larger facilities. (Author)