<p>Hydropower is an important part of world electricity, and still larger than all other renewable generation combined. It is highly economic, provides reliable, dispatchable power, and avoids most greenhouse gas emissions. Even though most of the best sites in Europe and the Americas have been exploited, there is still significant room for expansion in Asia and Africa. However, dams bring significant local environmental and social impacts, including habitat loss and human displacement. Dams on multinational rivers have become highly politicised and controversial. What is the role of hydroelectricity in future energy, and how can the negative impacts be managed?</p>
