Low Head and Very Low Head Hydro Power Generation

Hydropower captures energy as water moves from a higher area to a lower area. In Canada, low head hydro generally refers to hydro projects where the vertical difference in the high water and low water (referred to as “head”) is less than 15 m, and very low head hydro refers to those with a head below 5 m. In comparison to “conventional” hydro where a large portion of the potential resource has already been exploited, Canada has abundant untapped resources for low head hydropower development, with over 5,000 MW of identified potential.


There are many advantages to developing low head hydro:

  • Like most hydro technologies, the output is predictable; it is therefore one of the most reliable renewable resources for electricity generation
  • In many cases, low head hydro generation can be added where low head dams and other hydraulic structures already exist for flood control, irrigation, and water regulation
  • It requires a smaller impounded area than large hydro projects and therefore has less environmental impact
  • It can help Canada increase its use of clean power, particularly in remote locations where diesel generation is currently the primary source of electricity

Economic feasibility is currently the most important factor in the development of a low head sites as lower head means lower power output per unit of flow. Low head hydro needs to move greater volumes of water if it is to produce the same amount of electricity as conventional hydro. Conventional hydro turbine technology requires larger equipment and larger civil structures than low head hydro turbines, resulting in higher development costs. As such, conventional hydro technology cannot provide an economically viable solution.

Until 2010, CanmetENERGY worked with universities and the hydro industry to undertake research and development in new technologies to make potential low head sites more economically viable. Examples of these innovations include a variable-speed turbine system with reduced production and installation costs, as well as a specific very low head turbine design that significantly reduces the cost of on-site civil infrastructure.

For more information, please contact us.