Gravity from the sun and moon tugs at the surface of our oceans, creating tides that move massive quantities of water across broad expanses of shoreline twice a day. All that moving water produces kinetic energy we can convert into electrical power.
Though all of the earth’s continents have shorelines and tides, we haven’t done much with all that energy. To date, tidal energy technology generally takes two forms:
- Tidal current converters. These devices are typically underwater turbines that look much like a wind turbine and capture energy from water moving past the blades.
- Coastal barrages. A barrage is a kind of dam across the opening of an estuary. It works much like a hydroelectric plant, except that it uses turbines to capture energy from rising tidewater rather than river water.
Current technologies offer only a glimpse at tidal energy’s potential. To get the whole picture, we need to weigh the pros and cons of tidal energy.
Here’s a quick summary: (more…)
Wave power looks like a no-brainer at first glance. After all, oceans cover more than 70 percent of our planet’s surface, and waves lap up on the shores of all seven continents.
Just build machines to convert those waves into electricity and we’re all set, right?
Alas, wave energy challenges can be as deep as the ocean itself.
Fundy Bay is famous for pictures of fishing boats tilted on their hulls — run aground by the immense power of the world’s largest tides.
The waters of this scenic coastal inlet along Canada’s Nova Scotia and New Brunswick provinces rise and fall by more than 50 feet twice a day, every day of the year. That predictability is one of the key reasons why green-energy researchers are fascinated with the potential of converting tidal movements into electricity. Solar power goes dark after sunset and wind power rises and falls with moving weather patterns. But tides rise and fall like clockwork, creating the potential for an extremely reliable stream of electric power.
The Trouble with Tidal Energy
Unfortunately, the ocean is one of the worst places on earth to install mechanical equipment. Saltwater is extremely corrosive, and working on machinery underwater is incredibly dangerous and expensive.
Some wave and tidal energy projects are mounting turbines on the sea floor. This keeps the turbines out of sight, which is a boon to coastal views, but it also dramatically increases the costs of upkeep precisely because they are so difficult to access.
Floating Platforms: A Tidal Energy Alternative
Fundy Bay’s epic tides have made it a hub for working out these kinds of challenges in wave and tidal energy research. One alternative researches are exploring is mounting a turbine beneath a floating platform that’s moored to the ocean floor via cables. A turbine connected to a floating platform could have all of its machinery easily accessible from the platform rather than mounted on the sea floor, where the only way to reach it is with scuba divers or remote-operated vehicles (or both).
In March 2016, a Canadian firm called Dynamic Systems Analysis (DSA) helped launch a floating research platform called EcoSPRAY that will document how highly turbulent tides work. This, in turn, will provide clues to the best ways to deploy floating tidal energy platforms that have been moored to the ocean floor.
The platform is operating in the Grand Passage between Freeport and Westport, Nova Scotia, in the Outer Bay of Fundy. Sensors on the EcoSPRAY will track wind speeds, tidal currents and wave actions. A drag plate mounted on the bottom of the platform will simulate the thrust of an underwater turbine, DSA says.
Protecting tidal ecosystems
While floating tidal power platforms would be less visually pleasing than turbines mounted on the sea floor, they have the potential to be less disruptive to underwater environments. Mounting an underwater turbine is a major construction project, whereas placing anchor points on the sea floor for mooring cables could be far less disruptive to the coastal environment.
Protecting that environment is very much on the minds of Fundy Bay researchers. Fundy Ocean Research Center for Energy (FORCE), the Offshore Energy Research Association (OERA) and the Nova Scotia Department of Energy are all working together on a half-million-dollar program to determine the effects of tidal energy turbines this year.
This points to the future of wave and tidal energy, which may well depend on finding the best mix of high energy output, low cost and minimal impact on the subsea environment.
• EcoSPRAY tidal platform inspects moorings in high-tidal flows
• Fundy tidal energy study to look at seabirds, lobster, acoustic environment
In the United States, wave energy technology is less advanced than tidal. But as interest grows, companies like ours are prepared to equip these new tidal power companies with proven subsea cable hardware helping them become profitable sources of electricity.
Small tidal power companies are taking advantage of the rising interest in alternative energies. Large amounts of coastal waters are being reserved on both coasts of North America by small companies who plan to take advantage of ocean energy technologies, in the hopes that these sites will become profitable sources of electricity. Read more…
Forward-thinking and progressive companies will push sustainable energy technology and innovation further, testing its boundaries. These companies will advance as they see the value in environmental advocacy. They will be very focused on time and cost cutting methods. At PMI, we are looking into the future with these companies, helping reduce their costs through the use of hydrodynamic efficient hardware. Our in-depth hydrodynamic efficiency studies can be done on existing subsea devices for a complete cost analysis, as well.
In the world of energy, time and money are of the essence. Whether it be meeting projects completions, cost recovery or investor returns, entering the sustainable energy market has very real risks. All variables in the energy sector are related to time and cost. This is even truer in the sustainable energy sector. In order to get off the ground floor, in order to thrive, new emerging technologies and companies in this sector will require the removal of barriers to entry, which at times contain the much maligned red-tape. Read more…
Tidal energy farms require cables. And we understand that the lifetime of those cables significantly effect O&M costs. That’s why as the demand for tidal energy grows, we expect to find ourselves a long-time supplier in this market. Our product are designed to guard against cable and equipment damage, extend service life and maintain cable integrity in extreme underwater environments. Our hardware is proven to reduce the cost of maintaining subsea cables over time.
How the world is harnessing the power of the tides:
The Bay of Fundy is receiving a great deal of attention from proponents of ocean energy and from those in the industry seeking a more sustainable and green future. This 270 km long ocean bay is located in Atlantic Canada between the provinces of Nova Scotia and New Brunswick. The Bay of Fundy is where you will witness the highest and most spectacular tides in the world with 100 billion tons of seawater flowing in and out daily during each tidal cycle. This enormous power is currently being harnessed to generate electricity via tidal in-stream energy conversion (TISEC). Numerous projects and research initiatives are underway. With growing demand all over the world for renewable, clean, and carbon-free energy generation, tidal energy is quickly becoming a top choice over traditional wind and solar power. Read more…
As wind power grows in the UK, it is certain to grow in the US. PMI’s experience designing and producing reliable cable systems for offshore wind projects will benefit companies looking to innovate, increase performance and lower costs.
The UK Department of Energy and Climate Change has released results of a public attitude tracking survey, which shows support for offshore wind power has remained stable since the last survey.
According to DECC’s findings, support for individual renewable energy sources remain positive; offshore wind (74%), onshore wind (68%), wave and tidal (74%) and solar (81%). Read more…