Innovative hydropower designs
Why is this gap important?
Dams have a high social and environmental cost, heavily disrupting ecosystems and populations where they are developed. Alternatives that do not require damming or resettlement of populations would help reach SDS levels.
Zero-head or in-stream turbine technology has a lower environmental impact. No dams or head differential are necessary, they do not alter the course of a river and do not require high capital investments or large civil engineering works. The technology works best in areas where there are small water courses with discharge rates (the flow rate of water through a given cross-sectional area) of 1 m3 per second.
The recent surge of research activity and investment in technology to capture tidal energy has already produced successful prototypes. Most of these underwater devices have horizontal axis turbines, with fixed or variable pitch blades. Electrical generators tend to be direct or hydraulic drive, or have rim-mounted stators.
Relicensing dams to continue operation often involves more stringent environmental criteria that can have an impact on operations, limiting generation and impacting some of the flexibility and revenue streams of hydro plants. Complementing large installations with small-scale hydro plant such as in-stream turbines can therefore augment their generation.
Colored bars represent the Technology Readiness Level (TRL) of each technology. Learn more about TRLs