Tidal Power BC - Clean Energy BC

What is Tidal Power?

Tidal energy is the term used to describe the energy generated from power found in ocean tidal currents and the use of tidal height differences.
These two tidal energy sources are referred to as tidal stream and tidal barrage or lagoon.
Tidal streams are currents in the ocean water column, created as the water of the ocean rises and falls with the movement of the tides.
More recent commercialization efforts have focused on tidal stream technologies that harvest kinetic energy from the water currents.

Tidal currents are strongest where the water passage is accelerated around headlands, over shoals or in narrows.
Historical tidal energy developments focused more on barrage-style infrastructure where a dam-like structure is build across an area with a high tidal range.
The Annapolis Royal tidal energy station in Nova Scotia, which still operates today, is one of only three such power stations in the world.

The west coast of BC has been identified as having some of the best tidal energy potential in the world.
BC has numerous areas of tidal energy potential, located in the coasts many fjords and channels.
A 2006 tidal energy resource assessment identified 89 tidal energy project sites in BC with an estimated 4,000 MW of potential energy.
Modern tidal turbines are also being installed in rivers, irrigation canals, wastewater flows, and estuaries.
BC’s abundant river and estuary networks provide further renewable energy opportunities for the majority of its population.
Due to the nature of tidal energy, it is highly predictable and forecastable.

Tidal energy plants will be made up of arrays of individual generators in suitable high-current areas.
Each tidal energy device is designed use the energy in tidal stream flows to drive a generator to convert it to power.
There have been many tidal energy device designs, however three main methods are used:
- Cross-flow or vertical axis turbines
- Axial or horizontal axis turbines
- Reciprocating hydrofoils
CROSS-FLOW OR VERTICAL AXIS TURBINES – the turbine is placed in the tidal stream flow, as the water flows past, the vertical turbine blades move to rotate a central shaft driving a generator producing power.
AXIAL OR HORIZONTAL AXIS TURBINES – these turbines are somewhat similar to modern wind turbines; as the tidal stream flows past, the turbine blades rotate a horizontal shaft producing power through a generator.
RECIPROCATING HYDROFOILS – working like a fish’s tail and controlled by pitch, the hydrofoils are forced up and down by the stream flow transferring power to drive a generator.

In September of 2006, Clean Current Power Systems installed a tidal turbine at the Race Rocks ecological station.
The turbine, in combination with a solar and battery system, became the first complete ocean energy power system displacing diesel on the island.
New Energy Corp and Canoe Pass Tidal Energy have received federal SDTC funding and provincial ICE funding for a project near Campbell River.
The Canoe Pass project is the first tidal energy project to undergo the federal environmental assessment process.
Site investigations are underway for other potential projects.
In 2010 BC created the potential for an emerging energy feed-in tariff program that will assist in creating a market for this sector.

There are no known environmental issues for tidal energy.
Strategic Environmental Assessments have been completed in a number of areas, including the Bay of Fundy.
While concerns exist for ecological impacts and disruption to local fishing, mitigation measures will be implemented.
Research continues to be conducted on potential environmental impacts at a number of academic institutions.
Until devices have spent significant time in the real world applications, environmental impacts can only be estimated.

The power from ocean energy will be green electricity, using a renewable source of energy and not emitting greenhouse gases.
This decreases the need for fossil fuels for electricity production and aids in combating the effects of climate change.
Canadian green ocean energy will be in demand for energy exports.
Ocean generated electricity is a method of reducing the risk associated with price fluctuations of conventional fuel sources, creating energy price security.
Utilizing a number of different energy sources aids in energy security, decreasing the reliance on a single energy source, and increasing energy self-sufficiency.
Ocean energy project and device development will create direct jobs as well as employment for related industries such as marine manufacturing, engineering and oceanography, and power supply and service sectors.