This factfile provides an introduction to the technology and potential of hydropower.
Hydropower is by far the most significant renewable resource of electricity exploited to date. According to the IEA, the share of hydropower in electricity production will remain flat at its current share of 16%, or decline slightly by 2035, yet only about one third of the economic potential worldwide has been built to date.
In the OECD countries the best sites have already been exploited and environmental regulations constrain new development, although the construction of smaller size plants proceeds apace in many countries, and there is considerable activity in the refurbishment of existing schemes to extend their lives and, in many cases, increase their outputs. New hydro projects in developing countries are a massive area of development activity, following a maturing of our understanding of how to balance environmental, social and energy concerns.