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.
Topographical Challenges
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.
Technology Challenges
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.
Environmental Challenges
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.
Socioeconomic Challenges
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.
Offshore wind in the U.S. got a nice boost in June when the U.S. government announced that 81,130 acres off the coast of New York will be opened to leasing for offshore wind power projects.
Commercial offshore wind providers will have an opportunity to bid for leases they will need to develop wind farms in an area 11 miles south of Long Island. Although the U.S. does not have a single offshore wind farm up and running right now, the first project is expected to be operational by the end of 2016 and many more are on the way.
The U.S. Bureau of Ocean Energy Management has already awarded 11 commercial offshore wind leases worth $16 million and covering more than a million acres of U.S. waters, according to the BOEM website.
Nine of those leases have been sold through competitive bidding: Two each in New Jersey, Massachusetts and Maryland; two for an area between Rhode Island and Massachusetts; and one for Virginia.
Offshore wind power has a long way to go in the U.S., especially compared to Europe, which has over 3,000 wind turbines up and running. But U.S. several projects are in the works:
- A pair of six-megawatt wind turbines is proposed off the coast of Virginia. The BOEM has awarded a research lease for the project and approved a research action plan in March.
- An offshore wind project planned for Maryland could install as many as 125 turbines. It’ll still be a couple more years before construction starts, and two more years after that to complete the project.
- A more preliminary project is slated for the coast of New Jersey. That project is only in the opening stages. U.S. Wind, headquartered in Boston, is developing the New Jersey and Maryland projects.
- Another New Jersey project is being developed by Fishermen’s Energy, which won a Department of Energy grant to start a demonstration project near Atlantic City.
- DONG Energy, a Danish company that has done large projects in Europe, acquired the rights last year to develop a wind farm about 25 miles off the shore of Martha’s Vineyard.
The bottom line is that offshore wind will at least have demonstration projects up and running by the end of this decade to establish what works and what doesn’t.
The slow pace of adoption in the United States may frustrate advocates of renewable energy, but it’s important to remember that there was a time not so long ago when there were no wind farms in Europe. If oil prices jump and the political climate changes in ways that make offshore wind more attractive, we could see a lot more wind-power projects popping up off American shores.
After all, the technology is mature, thanks to the experience gained building Europe’s wind-power systems. A lot could change very quickly if all the right factors come together at the same time.
Companies that feel like they’ve missed the boom in offshore wind power technology may have the chance to ride a new wave of innovation with the rise of marine energy technology.
Converting the solar and kinetic power of our oceans into cheap, practical electricity seems like a far-off hope right now, but at some point the temptation to dive deep into marine energy methods and devices will prove too irresistible to pass up.
That’s something we’re watching closely here at PMI. Supplying equipment to companies that work in the oceans is what we do. Estimates suggesting the earth’s oceans could theoretically supply up to four times the world’s total electricity demand have definitely grabbed our attention.
Admittedly, it’s unlikely the oceans will ever supply all of humanity’s energy needs. But marine energy can become part of a diverse portfolio of renewables technologies like solar, wind and geothermal that serve the world’s energy needs while reducing carbon output and limiting global warming.
Looking Back on the Rise of Offshore Wind
It’s helpful to step back and look at how quickly offshore wind power became a mature technology in Europe. In 1990, there were no offshore wind farms in European waters. At the end of 2015, more than 3,000 offshore wind turbines were up and running, according to the European Wind Energy Association.
How many people could have projected that kind of growth in, say, 1980?
Obviously, nobody knows what the future holds. Marine energy is extremely expensive to develop and difficult to deploy right now. But it might not always be.
Potential Products and Devices in the Marine Energy Sector
European companies are already developing turbines and other devices to generate power from ocean tides and waves. These are big, expensive technologies that require substantial investments of time, energy and expertise. The companies working on them hope to exploit first-mover advantage and export their technologies worldwide.
As a supplier of subsea cable management systems, we see some interesting possibilities as these technologies emerge:
- Attachment points: One of the big challenges with marine energy is fixing devices to the ocean floor. Connections must be strong enough to hold energy devices in place and built to fend off the corrosion of saltwater. And they must be unobtrusive enough to have low impact on the undersea environment.
- Underwater vehicles: In an age when self-driving cars are already on the roads of Silicon Valley, it’s easy to envision rising demand for small submarines that can be put to work monitoring, repairing and maintaining marine energy devices.
- Pipe joints: One intriguing technology combines cold water from deep in the ocean and warm tropical water at the surface and creates electricity by exploiting the temperature differential. Called ocean thermal energy conversion, or OTEC, this technology requires pipes as long as several kilometers. Flexible pipe joints can help these pipes survive in ocean currents.
This list barely skims the surface of the possibilities in this sector.
Where the Marine Energy Sector is Going
Wave and tidal energy are getting the most attention right now. Costs for commercial development are still too high for this technology to become mainstream right away, but an encouraging collection of pilot projects in Canada, Europe and Australia — combined with the work of companies developing marine power devices — could lead to discoveries that can bring these costs down and encourage further development.
At PMI, we build accessories that make it easier to use cables in the ocean. Given that all marine energy devices have to transmit electricity over cables, we’re excited about the potential of marine energy.
But we also think that companies in a broad range of industries should be exploring these technologies and looking for ways to bring new products to market. If history is any guide, the people who invent the technologies that move marine energy into the mainstream stand to be forerunners of the industry.
Four intriguing technologies hold the potential to tap into the vast renewable energy of our oceans.
Nobody expects these marine energy technologies to replace coal, petroleum or natural gas in the near future. Instead, they could become assets in a diverse portfolio of technologies that can reduce our dependence on fossil fuels and temper the effects of climate change.
Let’s take a quick look at these marine energy conversion technologies.
Wave Energy
The natural up-and-down motion of ocean waves generates large volumes of kinetic energy. Wave energy devices capture this motion and convert it into electricity.
Some wave energy devices look like ocean buoys that bob up and down. Others string together a long, snake-lake chain of floating tubes. They can work close to land or farther out in the open ocean.
Wave energy is plentiful, but it’s also problematic. Waves rise and fall in multiple directions, and their velocity changes with the weather. That can make it difficult to get a reliable constant stream of energy. Also, only a few coastlines are optimal locations for wave-energy devices.
The upside is that several prototype wave energy devices are already in the water, and they’re yielding clues on how to make wave energy more practical.
Tidal Energy
Rising and falling tides generate substantial kinetic energy. The bigger the tide, the bigger the power potential. Tides rise and fall like clockwork, so tidal energy can provide a reliable stream of energy at specific times of day.
Some tidal devices look like underwater wind turbines. Because water is so much denser than air, the turbines can turn relatively slowly and still produce a worthwhile stream of electricity. Another tidal technology creates dams that capture tidal waters and uses turbines to tap the flow, much like hydroelectric plants.
Tidal energy’s impact on the subsea environment is a big unknown. Marine species may attach themselves to the devices, causing extra maintenance costs. Building tidal basins is expensive and disruptive as well. And large numbers of subsea turbines can affect the velocity of tides, which could shake up delicate undersea ecosystems.
Salinity Gradient Energy (SGE)
Salinity gradient power exploits the energy produced when saltwater comes in contact with freshwater.
The technology uses a membrane to separate saltwater from freshwater. One kind of SGE membrane generates an electrical current on its own, while another kind of SGE membrane produces pressure that can turn a turbine and generate electricity.
These membranes anchor the technology. They must be extremely large to produce abundant volumes of energy. Right now they are very expensive and prone to fouling by algae and other aquatic life, but new companies are already trying out new membrane technologies. Innovations in nanotechnology could potentially make SGE economically viable.
SGE could also work in wastewater plants to separate saline water and create electricity to help power the plant. That small-scale function could open the door to more substantial innovations that make the technology much more practical.
Ocean thermal energy conversion (OTEC)
Water at the ocean’s surface is much warmer than water in the murky depths. OTEC uses this temperature gap to produce electricity.
A complex system pumps water from up to a mile deep in the ocean. At the surface, a power station exploits the differences between hot and cold water to produce electric current. This requires no fossil fuel, and it can generate more energy than the pumping and production costs create.
This technology works best in the tropics in areas where there is at least a 36-degree F (20 degrees C) difference between surface water and deep water. It also requires massive pipes to pump the cold water up. But the energy is extremely cheap once the power plant has been built, so it’s an intriguing option in a few specific areas of the globe.
Why We Like the Potential of Marine Energy
At PMI, we have no illusions about the challenges of marine energy conversion. But we still think companies everywhere should be paying more attention to these technologies. In Europe, there’s a strong push to get 20 percent of the continent’s energy from renewable sources by 2020. That creates an incentive for a few bold pioneers to get more prototypes into the water and see how they perform.
Those incentives could create opportunities for companies that have specific expertise. PMI is just one example: We already provide some of the world’s most advanced accessories for the subsea cables that all of these technologies will need to transmit electricity to land.
Marine energy technologies will require advanced engineering to make them cost-competitive with fossil fuels. They’ll also need advanced materials designed specifically for subsea environments.
That looks like a wealth of opportunity for innovative firms that can help bring these technologies into the mainstream.
