The PMI team had a busy August having attended the ONS 2018 Conference in Stavanger, Norway. The conference not only provided a chance to connect with industry professionals, government officials, and catch up with clients, but also to learn more about what’s shaking up the market.
Innovation is the name of the game
Cost reduction through innovation was a common theme throughout the conference. More technological breakthroughs and policies are changing, providing the momentum oil and gas (O&G) industries need to continue to grow, evolve, and stay relevant. A number of ONS attendees were exhibiting alternative forms of energy including wind and wave.
One of the hottest topics of conversation was Equinor’s proposed plans to build the Hywind Tampen floating wind park. This park plans to reduce carbon emissions on Equinor’s oil and gas platforms. This kind of project displays some of the innovative ways the oil and gas industry is working to incorporate wind — especially floating wind projects — as a form of energy for offshore platforms. Offshore wind farms in the North Sea may be seeing more floating wind projects in their future.
A lot of discussions were also centered on O&G market conditions as the renewable fuel industries are now some of the fastest growing sectors. From our perspective, the majority of attendees felt there was a slight uptick in the market, but others had a more reserved outlook.
In addition, several seismic companies indicated an increase in activity, while other companies mentioned rounds of layoffs. It may be too soon to tell the ultimate trajectory of these markets, but we’re enlivened to see companies with new forms of energy coming to the table with creative solutions to today’s energy challenges.
PMI has been a key supplier for many companies within the oil and gas market, for nearly half a century. We offer full-service engineering from concept to production and provide cable protection and management systems for oil and gas and renewable energy projects.
While some other suppliers have closed doors, PMI has weathered the swings in market conditions by providing quality cable protection and terminations for our clients’ most demanding applications. This quality is what continues to set us apart from other suppliers.
PMI also stands alone in our low-hassle, no-tools-required cable protection assembly systems. Whereas other products, such as terminations, may require up to 12 hours to cure, PMI’s terminations can be completely assembled and ready to go in just 30 minutes.
Our experience working with projects across all sectors — oil and gas, wind, and wave energy — allows PMI to be an invaluable resource to our clients in all stages of their project development. In a world of tight timelines and budgets, PMI strives to create the cable protection systems that can remove the headaches and wasted time and energy so engineers can focus on their biggest project goals — not get caught up in cable complications. After all, about 80% of all project disruptions come from cable failures.
We’re always excited to attend ONS and it was a great opportunity to connect with some of our current clients and leaders from around the world. (PMI’s team even had the opportunity to meet with the U.S. Ambassador to Norway and mayors of Stavanger Bergen!). We look forward to seeing even more of our clients and connecting with leading industry professionals at several more of this year’s upcoming conferences.
With more than 95,000 miles of shoreline, the United States looks like an ideal candidate for offshore wind energy development. But it’s not that simple.
A substantial portion of U.S. shoreline tracks the Southern Atlantic states and the Gulf of Mexico, where the winds are either too weak most of the year or potentially catastrophic during hurricane season. The Pacific Coast has steady, powerful winds, but the continental shelf drops off sharply near the shore, requiring floating wind-power platforms that cost much more than fixed-position wind farms.
The economics of offshore wind present a second order of complexity. Offshore wind developers have to weigh factors including:
- Costs of competing energy sources like coal and natural gas
- Population density of the area using the power
- Availability of subsidies and renewable energy credits
- Expense of designing, manufacturing, and deploying wind farms
An intriguing study from the Berkeley Lab’s Electricity Markets & Policy Group developed a series of models to compare the economic value of offshore energy projects along the Eastern Seaboard of the United States from 2007 to 2016:
“The market value of offshore wind between 2007-2016 varies significantly by project location and is highest for sites off of New York, Connecticut, Rhode Island, and Massachusetts,” the study found.
States with most promising developments
In a May 2018 article, POWER magazine listed the most promising states for offshore wind. That roundup included:
- Massachusetts. With the doomed Cape Wind project finally out of the picture, the prospects for other offshore power projects are improving. The state government has passed legislation targeting 1,600 MW of offshore wind power by June 30, 2027. The law requires a buffer of 10 miles between offshore wind farms and inhabited areas to avoid angering the public, which prizes its coastal views. Three companies are bidding for projects off Martha’s Vineyard.
- Maryland. Two companies have been awarded renewable energy credits to develop wind farms of 120 MW and 248 MW. The credits are worth $3.6 billion over two decades. Developers are required to create nearly 5,000 jobs and invest in a steel fabrication plant and port upgrades. The project will involve 77 turbines from 12 to 21 miles offshore.
- New York. Gov. Andrew Cuomo would like to see 2,400 MW of offshore wind power developed in the next two decades. He wants to start with 800 MW in 2018-19.
- New Jersey. The state’s Offshore Wind Economic Development Act, passed in 2010, sets a goal of 3,500 MW of new power generation by 2030. The state’s Board of Public Utilities plans to solicit 1,100 MW of new projects, which would be the nation’s largest so far.
States and projects further down the coastline in Georgia and the Carolinas appear much less likely to bear fruit, the POWER magazine article explained.
Pacific Ocean possibilities
The Pacific Coast and the Hawaiian Islands each present intriguing opportunities because their terrain limitations require innovations in floating offshore platforms. Unlike Europe’s North Sea and the Eastern Seaboard of the United States, the shoreline of the Pacific plunges to depths that are impractical for the development of standard offshore wind turbines mounted on the seafloor.
In May 2018, the U.S. Navy complicated matters even further, stating that vast swaths of California coastline — including all of Southern California — should be off-limits to wind farms because the Navy needs that space for national defense purposes, the Los Angeles Times reported. The Navy cannot decide where wind farms will be deployed, but it has considerable influence.
Perhaps the best news for the Pacific comes from the coast of Scotland, where the first floating platform offshore wind farm is up and running. That wind farm is proving to be remarkably energy efficient, using up to 65% of its capacity factor, which is far better than land-based gas and coal power, according to Greentech Media. Capacity factor estimates a powerplant’s output as a percentage of its theoretical full energy output.
With the cost of developing offshore wind farms falling rapidly and floating platforms showing promise, power from the Pacific might be closer to reality than many observers suspect.
A wind farm project in the works near our home base in Cleveland will test the viability of the Great Lakes, which have ample wind, high population densities, and relatively shallow water.
The Icebreaker project plans to deploy six turbines in Lake Erie about 8-10 miles northwest of Cleveland. Supporters hope this pilot project becomes a catalyst for further development throughout the Great Lakes.
Offshore wind is coming to U.S. shores
Many coastal states have ambitious renewable-energy goals that will require the development offshore wind because there’s only so much they can do with solar, land-based wind, and biofuels. Fortunately, they can benefit from decades of European experience in offshore wind combined with steep declines in development costs.
U.S. wind projects also raise the prospect of bringing good-paying jobs and economic development to communities that need a boost after declines in their manufacturing base.
As a manufacturer of premium cable accessories for offshore wind and other marine-energy projects, PMI is doing its part to support the industry and help reduce our reliance on fossil fuels. We believe the United States is ready for offshore wind, and judging from the volume of new projects in the pipeline, we’re not alone in that assessment.
America’s First Offshore Wind Farm Is Finally Ready for Prime Time
Why the U.S. Should Embrace Offshore Wind
How Ice Could Impact Subsea Cables and the Great Lakes’ Offshore Wind Success
The Cable Challenges of Saltwater vs. Freshwater for Offshore Wind Projects
The challenges of developing practical, economical offshore wind power are pushing engineers and entrepreneurs to new heights — and depths — of ingenuity.
We’ve talked about the pitfalls and potential of offshore wind and other marine renewables for years in our Ocean Engineering Blog. We’ve noted that it’ll never be easy to build technologies that must be submerged in corrosive, turbulent subsea environments. And marine-renewables will remain a tough sell as long as oil prices stay low.
But these challenges haven’t stifled innovation in the ocean-renewables sector, especially offshore wind. Here’s a look at some of the encouraging news we’re seeing:
Autonomous underwater and remote-operated vehicles (AUVs, ROVs)
The cost of deploying ships and divers to inspect, maintain, and repair cables and other subsea components has been a costly drag on offshore wind farms for decades. Widespread adoption of versatile, low-operating-cost AUVs and ROVs can reduce those costs substantially.
As we learned at Subsea Expo 2018 in Aberdeen, Scotland, companies developing advanced AUVs and ROVs are adding new capabilities that, for instance, add a cutting tool to an inspection AUV. Another promising development is underwater charging stations that allow subsea vehicles to roam free without cables. Instead, the stations themselves have cable connections to power sources.
Larger, more powerful turbines
GE Renewable Energy’s forthcoming Haliade-X 12-mw turbine underscores the drive to build ever-larger devices that produce more energy in a single tower. Billed as the most powerful turbine on the planet, the Haliade-X will be able to power 16,000 European households with a single turbine. That means a single wind farm of 50 towers could serve 800,000 households — potentially a city of more than 2 million people.
Standing 260 meters high with a 220-meter rotor, the Haliade-X will produce 45% more energy than any other turbine on the market, GE says. It’s expected to start showing up in wind farms in 2021. For more on the size challenges in offshore wind, see this profile of former Siemens CTO Henrik Stiesdal in Wind Power Monthly.
The prospects for offshore wind farms on floating platforms got a boost in March 2018 when Statoil announced its new floating platform off the coast of Scotland reached a 65% capacity factor for November 2017 through January 2018 — besting a host of competing power sources. That news supports the principal rationale for floating platforms: deploying them farther from shore, where the winds are stronger and more consistent.
Capacity factor estimates a powerplant’s output as a percentage of its theoretical energy capacity. Greentech Media noted that U.S. onshore wind farms have a capacity factor of 37%, while coal- and gas-fired power plants have capacity factors of 54-55%.
Floating platforms could be the future of offshore wind, but most projects in the next few years will keep using towers anchored to the seabed. Current anchoring methods create an abundance of noise, disturbing sea life and generating concerns about the environmental impact of offshore installations.
A new alternative is the suction-bucket foundation, which uses a base shaped like an inverted bucket. It works like this: After the bucket settles on the seafloor, operators pump out all the water inside it, creating a pressure differential that helps fix the bucket in place. When it’s time to decommission the bucket, water can be poured back into it. The first commercial-scale suction-bucket foundation in a wind farm was installed earlier this year off the coast of Scotland, Powermag.com reported.
Here’s a look at recent research in the offshore-wind sector:
- Seabird avoidance. Seabirds have little trouble avoiding the spinning blades of offshore-wind turbines, a new study finds. Windpower Engineering & Development summarized results of the Bird Collision Avoidance Study, which used video cameras and high-tech sensors to track bird movements around a working wind farm in the English Channel. The study analyzed more than 600,000 videos monitoring activity at the wind farm. Of those, about 12,000 showed bird activity. Notably, the videos captured a scant six collisions over the course of the study.
- Anti-corrosion studies. Offshore Wind Journal reviews reports pointing to potential solutions to the nagging problem of corrosion in subsea environments. The reports estimated that reducing corrosion could generate savings in the tens of billions of dollars throughout the ocean-renewables sector over the next three decades.
Offshore wind keeps showing more promise
These updates offer just a glimpse of the encouraging developments in the offshore-wind sector. As turbines grow more powerful and engineers figure out new ways to reduce costs and protect subsea ecosystems, it will become ever more realistic to depict offshore wind as an experimental power source with mainstream potential.
Innovations Shrink Offshore Wind Timelines
Artificial Island Sparks Innovation In Wind Energy
Pros and Cons of Floating Platforms in Marine Renewable Energy
Ice hasn’t necessarily put a chill on the development of offshore wind in the Great Lakes of North America, but it does pose a significant challenge — both in the design of offshore wind turbines and the maintenance of subsea power transmission cables.
Winter is a wildcard for the Great Lakes because the offshore wind industry has traditionally avoided ice-prone regions. Most new oceanic wind farms can tap decades of knowledge gleaned from the maturation of Northern Europe’s offshore wind industry.
That’s not exactly the case for projects in water that freezes every year. The first wind farm designed specifically to cope with ice opened off the west coast of Finland in the autumn of 2017. The 42-megawatt Tahkoluoto wind farm relies on gravity-based foundations that are tapered at water level to resist friction with ice.
Ice and subsea cables
Reports on the Finnish wind farm have mentioned the tower base design but haven’t delved into the implications for subsea cables. We’re not privy to the technical specifications of the project’s subsea cables, but we can offer a few insights based on our decades of experience with subsea cables in harsh environments:
- The extreme weight and mass of ice place relentless pressure on anything in its way. Wind farms on the Great Lakes have to be designed with these risks in mind, laying cables strategically to keep them away from ice flows and buildups. The inherently unpredictable nature of weather and the motion of ice could conceivably surprise wind farm developers.
- Winter repairs will be extremely complicated. It’s difficult enough to send a ship to the site of a cable break in the open sea — it can take weeks or months to get a crew to the site, fetch the cable, repair it, and return it to the seabed. Imagine attempting repairs in the winter in the Great Lakes where variable weather changes the ice thickness constantly.
Engineers can design for the most likely scenarios for subsea cables, but there’s nothing like real life to teach us lessons we couldn’t foresee with ice and wind farms.
The value of wind farms in icy locales
The abundance of strong winds across the Great Lakes creates opportunities to develop new technologies and engineer novel solutions to icy problems. As ice resides along Arctic coastlines, wind farm developments could bring clean power to remote communities that otherwise depend on fossil fuels for heating and light.
However, we can only figure out so much of what is on the drawing board. To understand the depth of the challenges of ice in offshore wind, people need to build wind farms and learn the lessons nature inevitably provides.
At PMI, we look forward to engineering rugged, high-performance subsea cable accessories that will be critical to the success of wind power in the Great Lakes and beyond.
On average, European offshore wind turbines stand in 29 meters (95 feet) of water about 44 kilometers (27 miles) from the shore, WindEurope reports. These two stats underscore one of the key reasons why offshore wind in U.S. waters is a flyspeck compared to the installed capacity of European wind farms.
The first U.S. offshore wind farm added a scant 30 megawatts of electrical capacity when construction wrapped up in 2016. By contrast, grid-connected capacity of European offshore wind farms rose by more than 1,600 MW in 2016 alone — with 338 new wind turbines expanding total capacity to 12,600 MW, according to WindEurope.
European leaders deserve plenty of credit for achieving bold offshore-wind goals, but that’s not the only force at work in Europe’s offshore-power dominance. The waters of the North, Irish, and Baltic seas tend to be shallow near the shoreline and fall gradually to maximum depths.
This is the optimum terrain for today’s offshore-wind technologies — and it’s abundant. By contrast, the entire west coast of the U.S. plunges deeply into the Pacific Ocean just off the shoreline. The continental shelf on the Atlantic Coast and the Gulf of Mexico is much larger and shallower, but the specter of summer hurricanes casts a cloud on projects in warmer southern climes.
In essence, the most promising proposals for wind farms in U.S. waters lie in the cooler waters from the Carolinas northward to Maine. These waters boast a gently sloping continental shelf, much like the areas dotted with wind farms off the coast of Northern Europe. And while these northern waters are no strangers to fierce storms, they generally do not experience the destructive force of hurricanes.
Turning to deep-water development
Europe’s massive lead over North America in offshore wind shouldn’t obscure one central fact: European countries have fulfilled only a fraction of their offshore-wind power goals. And, like an apple tree bereft of low-hanging fruit, they have already developed many of the most valuable offshore-wind sites.
As offshore wind projects move farther from the coastline in Europe, naturally the water gets deeper. Soon, the fixed foundations for wind turbines will become prohibitively difficult to manufacture and install. This challenge invites the development of floating offshore wind platforms.
Floating platforms sound promising on paper, but only a few demonstration projects have gotten off the drawing board. But that could rapidly change in the space of a few years, according to WindEurope, the trade association for European wind power.
In a report issued in June 2017, WindEurope stated that floating platforms are ready for commercial development, and that costs could soon plunge as the technology enters the mainstream.
“Floating offshore wind offers a vast potential for growth,” WindEurope said. “80% of all the offshore wind resource is located in waters 60m and deeper in European seas, where traditional bottom-fixed offshore is less attractive. At 4,000 GW, it is significantly more than the resource potential of the U.S. and Japan combined.”
The report listed seven floating-platform projects in the works in Scotland, Ireland, Portugal, France, and the UK with nearly 350 MW of capacity that are expected to be commissioned in the next four years.
Taking a cue from offshore oil development
PMI has long provided premium cable accessories to oil-development companies, so we have a healthy respect for the difficulties in extracting energy from the deep ocean. And we’ve admired the ability of our industry partners to overcome these challenges.
But accidents happen despite the best efforts of the industry. Though floating offshore wind farms pose their share of environmental threats, there’s little chance of them being blamed for massive oil spills.
That’s one of the best reasons to be optimistic about the potential of offshore wind in the U.S. And as European developers build out floating platforms and drive down costs, American developers would be well advised to take advantage of the inevitable innovations that emerge.
A shallow patch of the North Sea is the site of an intriguing plan to reduce the cost and complexity of offshore wind farms.
Announced in March 2017, the plan calls for the construction of an artificial island to form the hub of a massive network of wind turbines. One key advantage of a hub is that it shortens the distance between the wind turbines and land — slashing cabling costs and reducing the risk of cable damage. The hub would then distribute the electricity to mainland power grids.
European power companies based in Denmark, Germany, and the Netherlands signed an agreement to launch a feasibility study for constructing the North Sea Wind Power Hub on Dogger Bank, which is just over 60 miles east of England’s coastline.
Media reports estimated the cost at around $2 billion and suggested it could go into development between 2030 and 2050.
Details on the North Sea Wind Power Hub
The current proposal calls for an artificial island of about 2.5 square miles with an airport, harbor, homes for staff and solar panels. Multiple wind farms could feed into the island hub, which would use direct-current cables to transmit energy to the mainland.
The developers say the project could capture up to 100,000 megawatts of power and serve up to 80 million people in Europe. The hub also could be a vital connection point in the energy markets of Northern Europe.
The developers are transmission system operators TenneT B.V. of the Netherlands, Energinet.dk of Denmark and TenneT GmbH of Germany. They signed an agreement in Brussels to work together on the Wind Power Hub project.
Why Dogger Bank?
The North Sea’s Dogger Bank is much shallower than its surrounding waters, making it an ideal location for wind farm development. Water depths range from 50 to 120 feet in the bank, which stretches across 6,800 square miles.
Dogger Bank is in the middle of a section of the North Sea bounded by England, Belgium, the Netherlands, Germany, Denmark, and Norway. The bank also is a well-known fishing area, supplying cod and herring to European markets.
Shallow waters and strong winds make Dogger Bank an attractive candidate for an offshore wind farm. But the project’s effects on major fisheries could be one of the major wrinkles to emerge in the feasibility study.
Artificial islands are feasible and practical
China’s construction of artificial islands in the South China Sea is one of the most high-profile examples of the engineering prowess required to enable these kinds of projects.
Though the islands may unnerve neighboring nations, they do establish the feasibility of building artificial islands in open seas. As a wind farm hub, an artificial island provides a central location for ships, planes, personnel and other resources that would have to cross much larger distances from the mainland, piling costs onto already expensive projects.
Achieving scale makes offshore wind more practical
The ultimate goal of the North Sea Power Hub is to centralize and standardize the far-flung operations of multiple wind farms. This creates economies of scale that make offshore wind much more practical.
Of course, significant challenges must be worked out. Building an island in the middle of an active fishery is bound to bring scrutiny from regulators and the fisheries industry — though at first glance it appears the island would be a mere speck in comparison to the overall size of Dogger Bank.
Wind energy is clean and sustainable, and open-ocean has the strongest winds. These twin forces make offshore wind one of Europe’s best candidates for meeting its ambitious goal of shrinking greenhouse gas emissions by 80 percent (from 1990 levels) over the next 30 years. That’s all the more reason to cheer the emergence of innovative offshore wind projects like the one proposed in Dogger Bank.
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In theory, thousands of miles of shoreline should make the United States an ideal locale for developing marine renewable energy.
But tapping the energy from all the waves pounding the shores of the Atlantic, Pacific and Gulf coasts of the U.S., is an incredibly complex prospect. A wide range of obstacles must be overcome.
The wide variety of sea depths in the offshore waters of the U.S. create a whole host of difficulties.
Tidal energy, for instance, needs tides to rise and fall at least 16 feet or more to be a practical energy source. Only a few places in the U.S., in Maine and Alaska, have tides that large.
Wave energy has great potential in some areas like California and the Pacific Northwest, which get a substantial volume of large waves (just ask the surfers), but it’s less attractive in areas where the waves are smaller like the Gulf of Mexico and much of the Atlantic Coast.
We can’t discuss marine energy without at least mentioning offshore wind. It’s not considered a marine-energy technology but it does go in the ocean, so it’s part of the ocean-renewable energy picture. The Atlantic and Pacific oceans are very different; what works in the Atlantic won’t work the same way in the Pacific.
Only a few ocean-energy devices are being tested in North America and we still do not have a clear picture of which technologies do the most good for the most people at the best cost.
Another challenge noted recently by The Energy Times magazine is that we need a lot more grid-connected test systems in place to see how these projects work when actually delivering power to the electricity grid. The U.S. Navy has one such grid set up for a wave-energy project in Hawaii, Energy Times notes, but projects in the works in Oregon are still not connected to the grid.
The United States has a robust environmental regime. Any marine renewable energy project in U.S. shores will face considerable regulatory scrutiny.
Devices will have to be anchored without causing substantial disruption to local underwater environments, and moving parts like turbine blades must not harm fish and other species. And there’s always the risk that a rare endangered species could doom an entire project.
Furthermore, the Atlantic and Pacific coasts host massive animal migrations every year, from birds to whales to great white sharks.
All these factors and many more will loom large with ocean-energy projects in the U.S.
America’s coastlines are a unique combination of priceless landmarks and economic lifelines. Installing mechanical devices off these coastlines can raise all sorts of thorny concerns, such as:
- Property values in coastal residential areas.
- Livelihoods of people working in coastal fisheries.
- Safety of shipping and recreation in the proximity of marine energy devices.
- Conflicting agendas of local, state and national leaders.
In short, ocean-energy projects pass muster with a nation that prizes its ocean views and protects its ocean resources.
Opportunities in Obstacles
At PMI, we’ve been supplying high-performance cable-accessory gear to the energy-development industry for decades. Marine renewables are like any energy source — they have to be developed in the most practical, economical way possible.
Sure, there are tough challenges to be figured out, but the history of people finding opportunities in obstacles is too strong to ignore.
While more than 3,000 offshore wind turbines push electricity to power-hungry Europeans, the number of towering turbines in U.S. waters is precisely zero. But that’s about to change.
The first U.S. offshore wind farm is slowly rising in the Atlantic Ocean south of the state of Rhode Island and east of New York’s Long Island. It could be up and running by the end of 2016, according to media reports.
The five-tower farm is small in scale and enormous in price: the $290 million project will provide energy to 1,000 year-round residents of a remote tourist stop called Block Island, where energy costs are extremely high because the island is more than 10 miles from the mainland. Developers of the project hope it will establish a toehold for offshore wind energy in the United States.
Once this project starts delivering power, it may be able to provide insights on economies of scale that will enable an industry to take root on the Eastern Seaboard. The relatively shallow Atlantic Shelf provides the only viable choice for the U.S. because the Pacific Shelf hugs the coastline and drops off sharply, making the waters are far too deep for wind farm development.
The large offshore wind farms of Europe rely on government subsidies and policies designed to push more and more European energy consumption into the green-energy sector, but such policies are far more rare in the United States. While investors have made wind turbines a common sight across the broad open plains of the nation’s interior, finding folks brave enough to try the untested waters of offshore wind energy in the U.S. another matter altogether.
High up-front costs, investor skepticism and lack of public-sector support equal slow going for offshore wind the U.S. Low fuel prices also are discouraging development of renewable energy sources. But eventually, hydrocarbon costs will rebound and make these kinds of projects more attractive.
The five towers of the Block Island project will be 600 feet high and designed to withstand a category 3 hurricane. Because the winds are stronger at higher altitudes and farther away from shore, wind farm developers have an incentive to build taller towers in ever-more-remote locations. The Block Island towers must be installed on platforms that sit on the seabed in several hundred feet of water — dramatically adding to the project’s costs. In the decades to come, floating platforms anchored to the seabed may provide a much more economical base for offshore wind energy projects.
Whatever the future holds, we’ll be providing the durable cable hardware that enables the offshore wind energy industry to transmit energy to people on land.
More on the Block Island project:
• First US Offshore Wind Energy Projects Could Deliver Jolt Of Momentum To Struggling Sector
• America’s First Offshore Wind Farm Quietly Takes Shape
Want to know more about our offshore energy efforts, schedule to talk to one of our experts today:
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
The offshore wind industry has fresh guidance on using reliable standards to determine the best depth for burying offshore wind farm cables.
In February 2016, the Offshore Wind Accelerator based in the U.K. published advice to offshore wind farm operators to help them ensure they are burying their power cables at a safe depth. This is a serious concern because power cable damage is one of the most common costs that threaten the success of offshore wind farms.
The advice is in the “Application Guide for the Specification of the Depth of Lowering using CBRA.” CBRA means “Cable Burial Risk Assessment Guidance” — which uses predictive modeling to help offshore wind operators get a greater handle on the risks of offshore cable burial. The hope is that CBRA will help the entire industry thrive by addressing the need for reliable, consistent cable-burial practices that are the standard across the industry.
Standardized offshore cable burial also can help fishing fleets, shipping lines and offshore oil developers reduce the risk that their operations will damage the cables tethered to offshore wind farms. Read more on the promise of new CBRA guidance in this update from Maritime Journal.
As a leading provider of subsea equipment, PMI is helping the offshore wind power industry address its cable safety concerns. Contact us for the facts on offshore wind cable hardware designed to withstand the rigors of the deep sea.
Have questions about your offshore wind power cables? Need tips on how to extend the life of your subsea cables? PMI has the answers – check out our free guide to Extending the life of you subsea power cables: