What is hydropower?

Hydroelectric power, or hydro power, is a clean, renewable and consistent source of electricity generation which uses the natural flow of water downhill.

There are several types of hydropower systems including: storage systems (common in Canada), where a dam creates a reservoir that releases water through turbines; run-of-the-river systems, where a river’s current pushes a turbine; and, pumped-storage systems where water is pumped to a reservoir at a higher elevation. All hydropower systems rely on converting the kinetic energy in water flowing downhill into electricity using turbines and generators. The energy available increases with a greater volume of water flowing and a higher drop in elevation.

Most hydropower facilities in Canada have water flowing through a pipe (penstock) to a turbine which the flowing water rotates. This moving turbine spins a generator which generates electricity to be sent to the grid. Facilities can differ in size and generation from very small to very large. For example, the Roddinckton Hydro Plant new the Town of Roddinckton in Newfoundland has a 0.4 WM capacity, but the Churchill Falls Hydroelectric Generating Facility in Labrador is 5,428 MW in capacity.

Hydroelectric power has been used for 2,000 years and modern hydropower turbine began in France in the mid-1700s. As of 2020, Canada had the fourth highest installed hydropower capacity of any country. Hydropower produced 60% of Canada’s electricity generation in 2019.

Hydropower Storage System

Source: U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Types of Hydropower Plants

What are the benefits and challenges with using hydroelectricity?

Several benefits of using hydroelectric power include it is a clean and renewable source of electricity generation, it provides a consistent supply unlike most other renewable energy sources (wind and solar), facilities have minimal operating costs, and typically have long lifespans.

Several challenges with using hydropower include high up-front project costs, which has seen cost and time overruns in several recent high-profile examples, environmental damage and displacement depending on the reservoir system.

What is the role of hydroelectricity in Atlantic Canada’s future?

Hydroelectric power plays an important role in Atlantic Canada’s current electricity generation. Existing hydroelectric infrastructure is valuable for the region, both in-terms of providing affordable energy, but also a reliable supply to help integrate more variable sources of energy like wind and solar onto our grids.

While resources in Nova Scotia and Prince Edward Island are limited, hydropower provides significant baseload generation to New Brunswick’s grid. Newfoundland and Labrador are rich in hydro resources and currently export significant amounts of hydropower to Québec and Nova Scotia.

The future of large-scale hydropower in the Atlantic region largely rests with two considerations:

  • Will Newfoundland and Labrador see additional hydro capacity built on the Lower Churchill River, such as the proposed Gull Island project?
  • Will an Atlantic Loop transmission project bring additional dependable hydroelectricity imports from Québec to the Maritime provinces?

These two questions are both hard to answer. The costs and risks of building new hydro projects and transmission could possibly discourage new developments. Governments and utilities need to ensure projects are financially viable and have public support. Growing electricity demand within Québec may also restrict Hydro Québec’s ability to export hydropower.

At a minimum, refurbishment planning work on some existing projects, like the Mactaquac Generating Station in New Brunswick, is progressing. These refurbishments will ensure hydropower will remain an important part of the region’s energy mix for decades to come.