Some are bobbers, others are turbines, and there are even models that move around like snakes.
They're all capable of harnessing electricity from the movement of our oceans, whether it's waves moving objects up and down or powerful tides that routinely push and pull.
Wave or tidal power doesn't get much attention in Canada, but technologies for extracting energy from ocean motion could end up following the same growth curves we have seen for wind and, more recently, solar power.
Canada's two coasts and Nunavut have the potential to generate more than 150 terawatt-hours of clean electricity a year using ocean or tidal power systems. This represents about a quarter of the country's annual electricity consumption, and the power would be predictable and constant – unlike wind and solar.
"Canada has the opportunity to be a leader in the long run on harnessing this vast renewable resource in a cost-effective, reliable way," according to Gouri Bhuyan, director of civil infrastructure and alternative energy technologies at Surrey, B.C.-based Powertech Labs Inc.
The question is whether we are taking advantage of this opportunity. On the surface it appears we're not, but behind the scenes there is activity going on. It may be a surprise to learn that Canada is the world's third-most active developer of ocean-energy technologies, behind only the United States and the United Kingdom.
We joined the International Energy Agency's "Implementing Agreement" on ocean energy systems back in 2003 to promote research, development and demonstration of such technologies. The countries in the group have a goal of seeing cost-competitive tidal and wave systems enter the market by 2020.
We're also one of the first to have a working commercial ocean-energy power plant. A 20-megawatt tidal plant was built in 1984 at Annapolis Royal by the Bay of Fundy. But since then the projects have been small and experimental – mostly demonstration projects, like the Race Rock tidal current system off of Vancouver Island.
There are currently about 10 of these smaller tidal and wave projects spread out between our west and east coasts, some of them funded by Sustainable Development Technology Canada. Canadian companies focused on the technology include Finavera Renewables, Blue Energy Canada, Clean Current Power, and New Energy Corp., and most are members of the Ocean Renewable Energy Group, which is a collaboration of industry, academia and government.
To help assist the development of new projects, Natural Resources Canada has created an ocean-energy atlas that quantifies and maps the best places in the country to establish tidal and wave systems.
The opportunities, however, aren't confined to Canada. The United States is beginning to wake up to the potential of ocean energy, and established energy companies such as oil giant Chevron Corp. are even getting into the game.
To help kick-start new projects, the U.S. Federal Energy Regulatory Commission announced last week it would speed up the licensing process for new ocean-energy pilot projects – down to six months from what can often take five years. It reportedly has more than 50 licence applications pending.
The Canadian government should follow this path, since regulatory barriers – perhaps more than technology and economics – appear to be a key reason why ocean energy has been slow to develop. This isn't to suggest we don't take a hard look at the impact of these systems on marine life, coastal erosion, navigation and water recreation, but for all these considerations the environmental effects are believed to be small.
We also have to remember that ocean energy is more than simply about generating renewable, emission-free electricity. It could also play a significant role in dealing with a coming global water crisis.
What's the connection? Desalination technologies that take salt out of ocean water will increasingly be relied on to address water scarcity problems around the world. Ocean-energy power plants can play a strategic, complementary role. By definition they have access to an endless supply of salt water as well as the electricity needed to turn that water into a drinkable product.
Drought-stricken Australia is serious about taking this path, as are a number of other coastal countries concerned about their long-term supply of water, including the United States. Clearly, future demand could be immense and the economic opportunities for Canadian companies equally massive.
Canada needs to make larger waves in this market.