Reviewing and critiquing published approaches to the sustainability assessment of hydropower

Recognizing the multidimensional role that hydropower can potentially play in achieving a more sustainable energy supply system, this paper reviews a series of published economic, environmental and social indicators that are often used to characterize this energy source. Getting the right balance between measures assessing benefits and costs is often a challenge in complex evaluations. The current paper argues that present studies sometimes set system boundaries too narrowly so that they omit key factors associated with hydropower. In particular, the role that hydroelectric resources can play to stabilize the overall electrical grid, and thus to leverage investments in other intermittent renewables, is only rarely accounted for in sustainability assessments. Based on a broad literature review, the authors articulate two key recommendations for future assessments: first, that such assessments should reflect on policy issues as well as environmental challenges with respect to existing hydropower potential within the current framework; second, that system boundaries should be extended not only to allow broad hydrological, ecological and geological assessments, but also to reasonably estimate hydro's potential benefits to the functioning of the overall electrical grid.