“WAVES TRANSMIT ENERGY, NOT WATER”
- NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION
For hundreds of years, engineers, inventors, scientists and tinkerers have been trying to convert the abundant, consistent power of ocean waves into electricity. Millions have been spent, leaving behind a trail of abandoned projects, but also a growing body of knowledge and insight that has been used to advance the technology. Companies on every continent have pursued designs to capture the waves’ energy, turn it into electricity, and last for decades in the turbulent, salty ocean. Generation after generation kept trying…. Why? Because wave energy is the most abundant, and one of the most reliable, powerful forces on Earth. Being able to make electricity from it could change the world. At last, it seems that we are a stone’s throw from being able to power cities and islands with clean, renewable, reliable ocean wave power.
Ocean waves are created when the wind blows across the top layer of the water. Wind pushes one part of the water down, which pushes another part of the water up. The longer and harder the wind blows across the water, the faster and larger the waves become. In fact, on large coasts like those of Western Europe, Africa, and the United States, the wind races over hundreds of miles, building the waves long before they arrive near the shore. Like light waves and sound waves, what’s being transmitted is energy; but in the ocean, it is embodied in heavy, dense water, so it packs a lot of power. That’s what can be converted into electricity.
But why do we need wave energy when we already have solar and wind energy? Here are 10 reasons why wave power is a game changer in renewable energy.
1. Wave energy is predictable
Grid operators have shifted less than 13% of the power they generate from fossil fuels to wind and solar because they can’t always predict how much power they will be able to pull from those resources. The wind dies down, a cloud blocks the sun, or the sun sets, meaning the power supply is cut off. But water is 800 times denser than air; it takes this heavy, dense medium a while to get going, and to slow after the wind has died down. Wave power may begin to build hundreds of miles from shore, and once it gets going it sustains for much longer. So grid operators can know how much wave power the ocean will give them up to two weeks before they need to use it. This steady wave power enables grid operators to confidently budget more renewable energy in their electrical supply.
2. Wave energy is powerful
It has been estimated that the power of the ocean’s waves would provide more than enough electricity for the whole world. Realistically, given inland populations, competition for coastal water real estate, and other challenges, wave energy might not take over energy production. But the U.S. Energy Agency says that, in theory, wave power could supply more than 60% of electricity consumed in the states.
A cubic meter of air weighs about 1kg; a cubic meter of water weighs about 1,000kg or about as much as a baby humpback whale. When a wave of energy is powerful enough to move something that dense, it can create a lot of force.
3. Waves are abundant
Seventy percent of the planet is covered by the ocean and its waves. Every continent and island is surrounded. In places like the west coasts of the United States, Europe, and Africa, the wind races across the ocean for miles and miles without being stopped, so it can generate huge waves in those places. But the real boon for the electrical power grid isn’t the big waves that appear sometimes; it’s the steady, consistent power of the moderate waves, rolling toward shores around the world, day and night, all year long.
4. Wave energy is reliable
Waves never stop. Even when the wind dies down, the waves continue because it takes them so long to build and subside. Also, the movement of the ocean is impacted by more than waves. The moon’s gravity constantly pulls on the oceans; and changing temperatures and salinity cause cold water to fall and warm water to rise, creating currents. Because the ocean never stops moving it never has to be “started up” from a standstill.
5. Waves are close to where people live
A challenge with wind and solar can be getting the power from where it is generated—in a plant far from a population center—to where it is used. Installing transmission lines is expensive and can be logistically difficult. And the farther the power has to travel, the more of it leaks along the route, reducing efficiency. Roughly 10 percent of the world’s population lives along coastlines with 40 percent living within 100km of a coastline. This includes huge cities and small islands that pay exorbitant amounts to import diesel to power their lives. So wave can provide a renewable that’s generated close to where it is used.
6. Wave power produces no emissions
Emissions created in the production and deployment of the technology vary by technology, but once in the ocean, wave energy creates no CO2 emissions. Electricity generation created the most CO2 emissions by far in 2022. Wave energy that creates even 10% of global power, displacing fossil fuels, could reduce CO2 emissions by about 1.5 gigatons. This means cleaner air for creatures on both land and sea, and a better chance to keep the global temperature rise below 1.5 degrees Celsius.
7. Wave power incurs no fuel costs
The cost of fossil fuels has a long history of creating global havoc. And for places that must import all their fuel, dealing with fluctuating exchange rates to purchase this substance that’s vital to their survival can result in crippling debt. The cost of building a fossil fuel generation plant is just the beginning. What follows is decades of payments of uncertain costs to buy the fuel to make those power plants work. But waves are free. Once the plant is built and paid for, the fuel comes from nature. Just as with wind and solar, once the technologies are deployed, the prices will continue to fall. As more and more wave parks are developed, the manufacture and installation of those parks will become exponentially more efficient, and prices will drop as they have with solar and wind. Soon, powering a community with wave energy could be among the most affordable options.
8. Wave energy can contribute to energy security
Many countries and communities are heavily dependent on polluting, expensive, imported fossil fuels. That puts them at the mercy of companies and countries that supply diesel, coal, and Liquid Natural Gas (LNG). Most islands, for example, tend to pay exorbitant electrical costs, far higher than on the mainland. These countries and communities know that extreme weather or geopolitics can create an existential threat by interrupting the delivery of the fuel they rely on for their homes, hospitals, and businesses. But many of these places have ocean waves. Once a wave energy park is built, they can convert those ocean waves into electricity and feel secure knowing they have a fuel source that can’t be taken away and comes free from nature. Wave power plants can provide energy security that can protect people’s lives and livelihoods.
9. Wave power can be used for desalination
As climate change progresses, global leaders worry that some places may lose access to drinkable water. Desalinating water, taking the salt out of ocean water so that it can be used for drinking, can be very energy intensive, which can accelerate climate change. Wave energy can be used in coastal areas to power desalination plants with CO2-free fuel.
10. Wave energy might help prevent coastal erosion
Some research has shown that because wave energy parks absorb some of the energy from waves rolling into shore, they have the potential to reduce coastal erosion and protect shorelines. This is a key environmental issue for coastal areas facing severe weather, rising sea levels, and other risks of climate change.