Tidal Energy
Source: Orbital / Eauclaire
What is Tidal Energy?
Tidal energy generates electricity from the natural rise and fall of ocean tides. Turbines are placed in areas with strong tidal flows – either on the seafloor or within structures like barrages. As tides move in and out, flowing water turns the turbine blades. That motion is converted into electricity, similar to wind power but driven by water.
Tidal power stands out because it is highly predictable. Tides follow a regular schedule set by the moon and sun, so operators can forecast when power will be produced. The predictability of tidal energy can also support the uptake of other variable renewable resources and help increase renewable electricity production.
Water is hundreds of times denser than air, making tidal energy a particularly powerful resource. Because of this density, tidal turbines can generate significant power using:
- Slower rotation speeds (for example, around 6 RPM for tidal turbines compared to about 20 RPM for wind turbines), and
- Smaller rotor diameters (roughly 15 metres for tidal turbines versus about 45 metres for wind turbines).
By using a steady ocean resource, tidal energy can help reduce fossil-fuel use, cut greenhouse-gas emissions, and support a cleaner energy future.
Tidal Technologies
Tidal energy technologies have advanced significantly in recent decades. New designs focus on generating more power while enabling flexible deployment and minimizing impacts on marine ecosystems.
There are several ways to produce electricity from tidal resources, using different types of technologies suited to specific sites and conditions.
In-stream Tidal
In-stream tidal turbines work like underwater windmills. They are placed in fast-moving tidal currents, where flowing water turns the blades to generate electricity.
These systems have become a leading focus for tidal development because they can be installed and removed more easily than older approaches, expanded gradually into larger arrays, and are designed to minimize environmental impacts. In-stream tidal is the primary technology being pursued for new tidal energy projects in Canada.
Tidal Range (also tidal barrage, tidal dam)
Tidal barrages operate in a similar way to conventional hydroelectric dams. A barrage captures seawater in a holding basin as the tide rises and falls. When the tide ebbs, the difference in water height between the basin and the open ocean creates potential energy. Releasing the stored water through turbines generates electricity.
Canada was once home to the only tidal barrage in North America, located in Annapolis Royal, Nova Scotia. When in operation, the facility generated up to 20 megawatts of electricity.
Two related variations of tidal range technology include:
Tidal lagoons: Rock-walled enclosures built along shallow coastlines to create a contained “lagoon” that captures tidal water for power generation.
Tidal fences: Arrays of tidal stream devices integrated with marine infrastructure, such as bridges, that span between two shorelines. These systems generate electricity from the kinetic energy of tidal flows while allowing some movement of marine life and maintaining more natural tidal circulation.
Tidal Energy in Canada
Source: Fundy Ocean Research Centre for Energy (FORCE). Bay of Fundy, Nova Scotia, Canada.
Canada is home to some of the world’s strongest tidal resources, with an estimated potential of up to 40,000 MW. The Bay of Fundy, between Nova Scotia and New Brunswick, leads the country, with tides exceeding 16 metres and a theoretical potential of more than 7,000 MW – enough to meet a significant share of Atlantic Canada’s electricity demand. Other promising sites include tidal channels in British Columbia and Nunavut, where smaller, community-scale projects could provide clean, reliable power for remote and northern grids.
Momentum is building on both the east and west coasts. Nova Scotia continues to lead nationally, with ongoing turbine testing at the Fundy Ocean Research Centre for Energy (FORCE) and growing interest from tidal energy developers around the world.
A major milestone was reached in November 2025, when Canada approved its first tidal energy array. Under a new, phased regulatory approach, Eauclaire Tidal is permitted to install up to three Orbital Marine Power O2-X turbines at FORCE. This step-by-step model allows projects to scale gradually while closely monitoring environmental effects, protecting marine life and giving investors greater confidence to support future expansion.
On the west coast, British Columbia is advancing parallel efforts through the University of Victoria’s Pacific Regional Institute for Marine Energy Discovery (PRIMED). This initiative focuses on off-grid tidal systems to reduce diesel use in coastal and Indigenous communities. Together with federal and provincial investments in research, development, and environmental studies, these efforts are positioning Canada to move from pilot projects to early commercial tidal arrays – and to export expertise into a growing global industry.
Tidal Energy Globally
Globally, tidal energy is moving from demonstration projects toward early commercialization. More than 20 countries are actively developing in-stream tidal energy, with the United Kingdom (U.K.), China, Canada, and France leading in technology deployment and real-world demonstration.
In the U.K., Orbital Marine Power and Nova Innovation have played a leading role in turning tidal energy into a reliable source of clean electricity. Orbital’s O2 floating tidal turbine has been generating 2 MWs of power at Orkney’s European Marine Energy Centre, supplying renewable electricity to the grid while supporting skilled jobs and marine services. At the same time, Nova Innovation’s Shetland Tidal Array has delivered steady, predictable power to local homes and businesses, demonstrating how small tidal arrays can serve island communities. Together, these projects have helped strengthen the U.K. tidal energy supply chain and reinforce the UK’s position as a global leader in tidal energy.
As of 2024, there is over 209 MW of in-stream tidal in development, with 11.5 MW operational.
Source: IEA-OES 2024 Annual Report: https://www.ocean-energy-systems.org/publications/oes-annual-reports/
The International Energy Agency’s (IEA) Ocean Energy Systems estimates 300 GW of wave and tidal to be developed by 2050, resulting in 680,000 jobs, $42 billion in investment and carbon savings of 500 million tonnes of CO2.
Another projection similarly shows strong decade-long growth driven by the need for predictable renewables. For Canada, this global ramp-up matters: world-class resources plus clearer permitting and first-of-kind arrays give Canadian firms a timely chance to scale at home and compete abroad.
Marine Renewables Canada envisions Canada as a world leader in both large- and small-scale projects, reaching 1 GW of installed capacity, with more on the way, by 2050.
Learn More
The Fundy Ocean Research Centre for Energy (FORCE)
Tidal Energy – Government of Nova Scotia
International Energy Agency – Ocean Energy Systems
International Renewable Energy Agency (IRENA) Tidal Energy: Technology Brief