Abstract
This study has compared the accumulated environmental impacts from 27 small-scale hydropower plants with 3 large hydropower projects. The results show a slight tendency that large hydropower has a lower degree of impacts than many small-scale projects, but lack of precision in the data and weak methodological foundation introduces uncertainty in the results. Taking into account other benefits such as the provision of regulated power, it is reasonable to assume that a few large hydropower projects will produce electricity to a lower environmental cost compared to many small projects, which should be considered when realizing renewable energy policy objectives. © 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of Renewable Energy Research Conference (RERC), Trondheim, 2012