The ocean is one of the largest untapped renewable energy sources on Earth, and people have been doing their best to harness its power for decades. The amount of energy available is enormous. In theory, waves on the west and east coasts of the United States could provide more energy. 60 percent Trends in the amount of electricity generated by the US power grid. Australia’s wave energy has the potential to create much more. 1,300 terawatt hours This is almost five times the country’s energy needs.
But the challenges are just as great as the opportunities. Seawater can corrode electrical components and rust mechanical components, often with devastating effects. For example, in November, a “bomb cyclone” hit the Oregon Ocean Energy Experiment Station, sending waves up to 19 feet in height from two different directions, said Burke Hales, an oceanographer at Oregon State University. “There’s a lot of power in waves like this, but there’s also a lot of risk,” he says.
But recently, accelerating efforts toward net-zero emissions, as well as slow but steady technology improvements and new investments, have sparked new optimism in the ocean energy sector. Biden administration takes office in September announced The Department of Energy’s Office of Hydropower Technology provided $112.5 million in funding for the prototype. This is the largest investment in wave energy in U.S. history. That office will also open in November. issued Twenty startups will each receive a $10,000 prize. Key to these investments is a new test site in Oregon developed by the Department of Energy, Oregon State University, and local stakeholders that includes four “parking spots” for wave energy prototypes. Pacwave South, where Hales is scientific director, plans to join several other testing sites around the world and host its first companies in summer 2026.
“We are often asked why we use wave energy instead of solar. It’s just wave energy and solar,” says the offshore engineer.
Hales and his colleagues believe the field is at a tipping point that will eventually yield commercial success, with some designs finally emerging that can withstand the brunt of both maritime and financial realities. “It’s expensive and difficult, but I think the opportunity is huge,” said Lindsay Bennett, executive director of the Fundy Ocean Energy Research Center (FORCE) in Nova Scotia, Canada, which studies tidal energy. She sees the ocean energy sector “making huge strides over the next three to five years.”
Currently, about half of the renewable energy on the planet comes from hydroelectric power. Wind turbines and solar panels together make up most of the other half. According to the International Energy Agency, renewable electricity generated by ocean tides and waves in 2020 accounted for just 0.2% of the world’s renewable electricity. Although the IEA predicts that ocean energy’s contribution will remain small, it is one of the fastest growing renewable energy sectors. Government agencies in 2021 Net-zero roadmap to 2050Ocean energy generation will increase more than 60 times by 2050. Ocean Energy Systems is the IEA’s ocean energy technology cooperation programme. ambitious course By 2050, the world could increase ocean energy from the current approximately 1 gigawatt to a whopping 300 gigawatts. They believe the effort will include 200 projects totaling $1.5 billion.
Three types of wave energy devices (from left to right: point absorber, gyroscope, and attenuator).
Aqua RET
“We are often asked why we use wave energy instead of sunlight. and solar power,” says Hugh Wolgamott, an offshore engineer at the University of Western Australia. “At the moment it is more expensive than other renewable energies, but the key is its sustainability value.”
“It’s definitely just one piece of the pie,” Walgamott said. But to achieve net-zero emissions, “we need to pull all the levers and we need to act very quickly.”
As history shows, it is a difficult road. Opened in 2004, the European Marine Energy Center in Scotland’s Orkney Islands is perhaps the longest-running testing site for modern marine energy projects, connecting prototypes to the power grid and facilitating permitting paperwork. We provide services. EMEC hosted the earliest wave projects to transmit energy to the power grid. Pelamis Wave Energy ConverterThe device resembled the sea serpent from which it took its name, and had long floating metal tubes that bent around each other to drive hydraulic pressure. The machine produced electricity, and several more versions of the machine were subsequently developed at several locations, but the company collapsed under financial strain in 2014.
Devices may be installed between the towers of offshore wind farms to obtain power from both wind and waves.
One particularly long-running device in EMEC is the Penguin, developed by the Finnish company Wello Oy. This round floating barge was unevenly weighted, so it spun over waves like an amusement park ride. An internal generator converted this movement into electricity. “It’s an interesting machine and a smart idea because there’s nothing really moving where it’s in contact with the seawater,” said civil engineer Neil Kermode, managing director of EMEC. says. One version began testing with EMEC in 2011, worked successfully for several years, but sank in 2019. Wello Oy filed for bankruptcy in 2023.
EMEC alone has tested approximately 35 devices over 20 years with varying degrees of success. The problem is that these systems typically cost millions of dollars to develop and build because they need to be tested at scale at sea rather than in wave tanks, Kermode said. But the companies building them are often small startups. “All of these guys are absolutely living on the edge,” he says.
However, many trials continue, and some will use the PacWave South testing site. One, developed by California-based CalWave, is a floating disk tethered to the ocean floor that rides the circular motion of waves. If the water gets too rough, you can winch downwards and continue working in calmer conditions underwater. In contrast, Virginia-based C-Power plans to test a floating raft with a hanging pendulum.
A wave energy system installed on the breakwater in Mutliku, Spain.
dpa Picture-Alliance Archive / Alamy Stock Photo
Meanwhile, Stockholm-based Copower has significant funding to support vertically moving buoys that harness wave energy, which it aims to install in “wave power plants” in the near future. . Such wave power plants host a large number of devices and are considered the best way to scale up wave power to utility-scale power generation. They are sometimes installed between the towers of offshore wind farms to obtain power from both wind and waves.
Single-wave power units could also be useful in custom locations, such as remote areas in Alaska where wind and solar resources are scarce. Waves could also be used to power local energy needs, such as refrigeration for fisheries or dredgers to clear shipping lanes. Some companies, such as Boston-based Resolute Marine, are interested in harnessing waves to power energy-intensive desalination plants. Many experts, including Hales, are keen to install wave power systems inside breakwaters to protect beaches from wave damage. Several such projects already exist, such as the Mutliku Breakwater Wave Power System in Spain’s Basque Country, which has been in operation for 10 years.
Some tidal projects also have fairly long histories of successful operation. These systems can be simpler than wave energy projects because they deal with water moving primarily along a single axis as the tides rise and fall. Most tidal devices have either a propeller or a water wheel and are installed in narrow, channel-like areas with particularly strong currents.
“There’s a lot of energy out there, so we’re going to go get it,” says the director of Scotland’s wave energy facility.
For example, the MeyGen project in Scotland has been operating continuously since 2018 with four 1.5 megawatt tidal turbines. Each looks like a massive wind turbine, with rotors measuring about 60 feet in diameter. The project is expected to eventually reach nearly 400 megawatts, with plans for a larger expansion of dozens of turbines. 2024 report The European Commission’s advisory body predicts that ambitious action could increase tidal power generation in Europe by up to 700 MW by 2028. For example, France recently announced plans for a relatively large (seven 2.5 MW turbines) tidal power plant, scheduled to open. In 2026.
However, tidal power also faces challenges. Developers have long been interested in harnessing tidal energy, for example, in the Minas Strait in the Bay of Fundy, Nova Scotia, which contains more water than all the rivers on Earth combined. It is flowing at a speed of 5 meters per second. However, only three devices were tested here, probably because the currents were so strong. Overall, FORCE’s Nova Scotia Bennett says, the state is far behind its goal of bringing 300 megawatts of tidal energy to the grid by 2030.
Tidal turbines installed at the Meygen Tidal Energy Project in northern Scotland.
Majen
A further concern facing both tidal and wave energy projects is the potential for environmental problems. 2024 report IEA marine energy systems researchers have concluded that some of the theoretical risks from offshore power generation are small enough to be “decommissioned”, meaning regulators must fully investigate the risks of each new project. It does not mean that we can reasonably rely on what is already known. This includes the potential for harm to marine life due to changes in conditions such as electromagnetic fields, underwater noise, and food supply, at least when there are fewer than six devices (the report notes that large-scale farms may be at risk). (states that it may be necessary to reevaluate the However, more information is needed to understand potential risks such as displacement of marine life, collisions and entanglement with mooring lines, the report added.
Researchers have expressed concern that propellers from tidal power projects could hit fish, for example, but assessing those potential hazards has proven difficult, Kermode said. . the force is now plan Tagless fish tracking programs use cameras, sonar, and artificial intelligence to assess these risks.
Kermode says there is “a long way to go” to develop the technology to a place where wave and tidal energy can reach its full potential. But recent U.S. investments are a positive sign for accelerated action, he said.
“when [movers in the U.S.] When you wake up and decide to do something, that tends to happen,” Kermode says. “There’s a lot of energy out there, so we’re going to go get it. It’s going to take longer than planned just because of when it happens.”
