Wave power has the potential to be one of our most abundant energy sources because seas cover 70% of the Earth’s surface. You may have experienced a small amount of that force if you’ve ever been thrown off your feet by a strong wave.
For many years, engineers and scientists have fantasized about ways to capture a little portion of the energy contained in our huge oceans. Finding ways to do that is finally receiving greater attention in a time of climate awareness and worry.
The ocean presents significant potential for renewable energy, both from offshore wind power and less-explored sources including waves, tides, and currents, according to the Biden administration’s Ocean Climate Action Plan. Even the colder waters deep beneath tropical seas might be able to supply clean marine energy.
The plan recognizes an ambitious project that is almost finished off the coast of Oregon, where 7 miles of pipe were built beneath the Pacific Ocean’s surface using cutting-edge horizontal drilling methods. The mainland will soon be connected to PacWave, an offshore experimental testbed created to research and showcase innovative technology that turns the energy of waves into onshore electricity, by running thick cables through that conduit.
PacWave could produce up to 20 megawatts once it is fully operational (perhaps in 2025), which is sufficient to power a few thousand houses. Levi Kilcher, a senior scientist at the National Renewable Energy Laboratory, told me, “I get extremely enthusiastic about wave energy because the resource is so huge.
The 2021 NREL report, which collated information on marine energy sources in the US, including waves, tides, and ocean currents, had Kilcher as a main author. According to the research team, the overall energy potential is greater than half (57%) of the electricity produced in the US in a single year.
“Because there is such an abundant resource, I get very excited about wave energy.”
Senior scientist Levi Kilcher from the National Renewable Energy Laboratory
Wave energy still has a ways to go before it is a substantial source of electricity, despite the fact that experimental sites like PacWave show an effective approach to gather wave power and may help with breakthroughs. Though waves are constant, their differences present a significant problem when creating a device to harness their energy.
“You’re trying to tune [the technological approach] so you can take advantage of these shifting kinds of waves,” said senior researcher Andrea Copping of the Pacific Northwest National Laboratory.
Devices that ride on top of waves or ones that convert the pressure waves put on the seafloor into electricity are two different ways to capture wave energy. Oscillating water columns are a different method that compress the air as the waves pass over them. A turbine is spun by the compressed air to produce energy.
From the depths, power
Researchers and authorities are looking into several maritime energy sources, including waves.
According to Copping, interest in ocean thermal energy conversion, often known as OTEC, which involves bringing up colder water from deeper ocean regions, has increased. Similar to how home heat pumps exchange hot and cold air, this chilly flow subsequently through a heat exchange procedure with warmer surface water. A turbine is turned by that process to produce power.
When energy prices were at an all-time high in the 1970s, OTEC technology was developed, but it never really took off. According to Copping, the increased interest in OTEC as a result of climate change may be appropriate for small South Pacific islands like Guam and Puerto Rico.
There is genuine interest, and Copping asserted that he believes it will succeed this time.
In Hawaii, a modest OTEC facility has been operational for some time. Copping is optimistic about the future of the technology, which has attracted a lot of attention from Japan and other nearby countries, thanks to recent US government promises.
Concern over climate change might open up new financing opportunities for OTEC. The technology is becoming more economical in the interim, according to Copping, by creating smaller plants (10 megawatts or fewer) and locating them on land as opposed to in the water.
Additionally, in the tropical regions where OTEC performs best, the cold water pipes can function as a sort of air conditioning.
Following the flow
There is minimal likelihood of finding surface water warm enough for OTEC along much of the US coastline, including Alaska, the Pacific Northwest, and the rocky beaches of Maine. Fortunately, some of these locations are ideal for producing electricity from tides, a source that depends on shallower water.
Kilcher was always captivated by the strength of tides because he was raised in Alaska. He was unaware that the adjacent Cook Inlet is regarded as one of the world’s best locations for capturing their energy. Kilcher was shocked to learn from coworkers at the National Renewable Energy Laboratory that his birthplace of Homer, Alaska, was one of the top tidal energy locations in the world when he first started working there.
Tidal energy technology is the most advanced when it comes to using ocean currents to generate electricity; all it requires is placing the right turbine in the proper location in the sea. Numerous tidal-power plants have already been put into operation in Europe and other regions, as well as in specialized uses all over the world.
The antithesis of wave energy is tidal energy. Although they can occur everywhere, waves are difficult to forecast. Tides are a generally well-known number that occur everywhere, yet their power potential is only present in a few relatively limited locations. Only in small channels or between islands and the mainland can one normally find the fast flows needed to produce electricity. However, tidal energy is a fairly dependable source of renewable energy where it is used.
Tidal energy is particularly appealing because it is completely predictable, according to Kilcher.
Smaller studies are being conducted using ocean features other than tides, such as the oceans’ dominant, slowly moving currents. Kilcher mentioned that studies are being conducted to determine how much current energy can be extracted before it affects heat circulation patterns in the North Atlantic off the coast of the Southeast US.
“You don’t want to be extracting so much energy that the Gulf Stream starts to shut down,” he advised. “We look at these kinds of scientific research questions,”
She blows there
So far, the air above the ocean has more to do with effectively drawing power from it than the water itself. The power we transmit from the ocean to land is by far more productive when it comes from offshore wind.
According to Bryson Robertson, director of the Pacific Marine Energy Center at Oregon State University, “offshore wind is without a doubt the most mature technology.” Since the dawn of civilisation, we have been developing wind energy systems. We were using windmills to process wheat while also operating sails on boats.
Since the dawn of civilisation, we have been developing wind energy systems. We were using windmills to process wheat while also operating sails on boats.
Bryson Robertson, head of Oregon State University’s Pacific Marine Energy Center
Off the coast of the northeastern states and other locations, it has become commonplace to see large, power-generating wind turbines moored to the seafloor. According to Robertson, a more recent, promising invention that might assist increase the amount of electricity we essentially generate out of thin air is floating offshore wind turbines.
Offshore wind is more reliable, and floating infrastructure can be set up in more locations and on deeper seas. Additionally, taller turbines might be able to access high-altitude winds in places that are hidden from public observation.
Robertson thinks that increasing wind power production from floating infrastructure has the potential to significantly reduce carbon emissions.
a challenging setting
Building the infrastructure to draw power from one of the most hostile and untamed places on Earth can be a slow, challenging process, unlike producing a new mobile app or even a mobile phone.
“We know less about these tidal raises, these big wave areas because we stay out of them,” Copping claimed. “That’s one of the causes for the delay. However, it’s difficult to miss the ocean’s energy potential when you simply gaze at it.
Other factors to take into account are the effects maritime energy infrastructure might have on local communities, the ecosystem as a whole, wildlife, fishing, and other sectors.
Uncertainty, in my opinion, is the main problem, Robertson continued. What will the environmental effects be since we haven’t done anything on this magnitude before?
The demand for marine energy, he claims, is still essential even though the policy-making process may be slow for legitimate reasons.
He remarked, “We need to figure out how to deploy technologies faster while being aware of the environment. “If we’re going to have a measurable impact on climate change,” the author said, “we just need to find a way to accelerate this process.”
