Small Hydropower | Low Head and Very Low Head Hydro Power Generation

Hydropower captures energy as water moves from a higher area to a lower area and the “head” is the vertical distance over which this energy is captured. In Canada, low head hydro generally refers to hydro projects where the head is less than 15 m, and very low head hydro refers to those with a head below 5 m. In comparison to higher head 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 electrical 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 site as lower hydro 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 high head hydro. To achieve this using conventional hydro technology requires larger equipment and larger civil structures, resulting in higher development costs. As such, conventional hydro technology cannot provide an economically viable solution.
CanmetENERGY works 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 turbine with simplified structural design and 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.
CanmetENERGY and the University of New Brunswick have partnered to develop a permanent magnet generator and power converter for low head hydro applications. This system not only eliminates the need for some expensive equipment used in conventional turbines, but also enables the turbines to operate under variable speed, allowing the turbines to constantly operate at maximum efficiency. All of these factors greatly improve the economics of developing low head hydro sites.
CanmetENERGY also collaborates with industry, utilities and government agencies to identify challenges and barriers in furthering the use of low head hydro, and in developing strategies to support low head hydro technologies.
For more information on Low Head Hydro, please contact us.