18 Biggest Pros and Cons of Ocean Tidal and Wave Energy

Wave energy gives us the option to capture and transport what the ocean provides us with its surface waves. What we collect from this technology gives us the option to manage several different types of useful work, including water desalination, water pumping, and electricity generation. This form of renewable energy is one of the most significant global resources that we have when included in the conversation with geothermal, wind, and solar.

The first patent to generate wave energy dates to 1799 when Monsieur Girard and his son proposed using the movement of the water to create direct mechanical actions in 1799. There were 340 more patents issued in this space between 1855-1973 just in the United Kingdom. Then a Japanese naval commander named Yoshio Masuda helped to modernize the energy collection processes after testing several device designs at sea.

There are five primary technologies used to collect energy from the water through the use of wave energy. You have a float, spar, and heave plate that interact with the movement of the water. Then an undersea substation routes the energy to shore while cables connect each additional buoy to the collection point.

List of the Pros of Wave Energy

1. It is a highly accessible for of energy for most coastal nations.
Wave energy has plenty of potential thanks to the powerful movement of water around our planet. 71% of the Earth’s surface is water, which means our accessibility to waves is quite strong. Although landlocked countries are unable to access this resource, those with access to a coast can have confidence in the fact that the ocean is not going to disappear any time soon. For every meter of wave that comes along the shore, the energy density measurement is up to 40 kilowatts.

That means the United States has an energy potential of more than 2,600 terawatts along the continental shelf edge. It is not unusual for the wave energy to rise to 50 kilowatts per feet of wave as you move further away from the shore.

2. Wave energy is an environmentally friendly option to consider.
If we are able to harness the energy from ocean waves to generate a majority of our electrical needs, then we can reduce our reliance on carbon-producing fossil fuels. There are fewer particulates to worry about in the manufacturing processes of collection equipment with this option as well when compared to what coal-fired power plants reduce. Although we’ll still be making a capital investment using petroleum products and natural gas when building these facilities, it will not take long to recoup that investment with the amount of power that is possible with this technology.

3. It is a renewable energy resource that we can use around the world.
Wave power is a highly renewable source of energy that doesn’t suffer from gaps like solar and wind options. Because heat energy and gravity create water movements that cause surges near the short, we don’t need to worry about whether or not there will be future availability with this technology. Unless the climate changes so drastically that we lose our ocean or the sun decides to suddenly disappear, we’ll still have access to the power we need to maintain our modern lifestyle almost indefinitely.

4. We do not need land installations to manage the power from wave energy.
Because this technology harnesses the power of the waves, there is no need to create a land-based installation to collect power. There is a larger energy potential found in the waves than what our current power plants produce without the same threat to human life. It takes less than a one-half of a square mile to generate about 30 megawatts of power, which is the level needed to power about 20,000 homes.

We can supplement this energy with solar and wind from the grid to reduce or eliminate the need for our aging power plants. When the flexibility of this technology is factored into the equation of electricity generation, there is a real potential for environmental support when we use this technology.

5. It provides a predictable energy resource that we can use.
Wave energy can work in two different ways: we can harness what crashes to shore and through the use of tidal collectors. The gravitational fields from the sun and moon, along with the rotation of our planet, create high and low tides that are exceptionally predictable. We can use this information to place collectors in the best possible locations to ensure the energy we collect can be transferred to our greatest needs.

Even though there are waves at almost every coastal location, some locations have stronger cycles than others. With the information from this advantage, we can build systems with the correct dimensions since we know what the exposure levels for the equipment will be in each circumstance.

6. Wave energy is very effective at slow speeds.
One of the reasons why most nations began to look at hydropower as an alternative to coal was because the speed of the water doesn’t need to be very high to generate results. When you compare the density of water to what we experience with air, the fluid is 1,000 times denser. That means we can generate electricity even if the waves are moving slowly. As long as there is one meter of movement for every second (about three feet), then we can collect energy from the ocean.

7. It reduces the need for mining and excavation activities.
Although wave energy collectors would need to use raw materials for the manufacturing process, we would not need to continue processing fuel from our excavation sites if we could transition to this technology. Coal-fired power plants require a constant production of this fuel for there to be power. Since this problem goes away with this technology, there would be less of a need to create scarring surface mines and other problematic extraction methods to give us the power we need for our modern lifestyle.

8. Wave energy would reduce the reliance that some countries have on foreign oil.
The development of wave energy technologies, along with other renewable fuels, would decrease or eliminate the dependence of a national economy on foreign imports of crude oil. Even though we use hydrocarbons in a variety of products, it is possible to source this manufacturing material from plant-based items as well. That means consumers could save money and have more predictable financial costs because the presence of this technology would help to stabilize the power grid.

9. The operational costs of wave energy are very low.
One of the advantages of wave energy is that you can place them near the coastline or away from areas where there could be conflicts. Although the initial installation and manufacturing costs are somewhat significant with this technology, there are fewer operational costs to consider. Most farms can operate independently once they go online. That means you only need to have periodic inspections and repair missions to fund when there is damage or the equipment malfunctions for some reason.

This advantage comes with a secondary benefit as well: there are no fuel costs. That keeps the long-term costs of wave energy down as well. If a community can get past the initial expense of this project, their costs become much more bearable over time.

List of the Cons of Wave Energy

1. The presence of a wave energy farm negates the use of the area.
If you have energy collection equipment in place to harness the energy from the incoming waves, then that area of shoreline becomes inaccessible. You would need to install a dedicated path between the floats and other items to avoid damage from boats or injuries to swimmers. Many coastal facilities must meet size restrictions based on their location that could limit the amount of power that they could collect as well.

There would be adverse impacts to tourism and possibly local acceptance of the project once installed. Since the water area becomes unusable, there could be economic issues.

2. We do not know how marine life is impacted by this technology.
Jeff Ward, an ecologist with the Pacific Northwest National Laboratory, says that marine life impacts with tidal energy devices could be impacted because many species rely on the magnetic fields of the planet to search for food or migrate. The cables and hydrokinetic devices that produce energy with this technology create similar fields.

“We really don’t know if the animals will be effected or not,” Ward said. “There’s surprisingly little comprehensive research to say for sure.”

3. There are cost considerations to look at with wave energy.
Tidal energy is still in the early stages of its overall development. That means we are looking more at a speculation of the costs that are possible with this technology instead of concrete estimates because we are still going through the R&D process. At the moment, the power plants which have gone online have cost about $44 million to create, but it would cost about $1.6 billion to put one into play in the United States. That would place the cost at $0.197 per kilowatt hour, which is more expensive than a new nuclear plant. Since that price excludes financing costs as well, the price for collecting energy from waves is about double that of what it would be to get wind energy.

4. Wave energy has siting issues to consider.
When we look at the current technology that can harvest energy from the waves and tides, there are specific requirements that a specific site must have for it to be a good candidate for this energy production option. There must be a tidal range of at least 23 feet for this option to be useful, with wave movement that occurs with speeds of at least 3 feet per second. Even though there are thousands of miles of coastline around the United States, our current technology in this field means there are only a handful of economically competitive locations to start building.

Out of the total amount that is possible from wave energy around the U.S., only 0.6 TWh is currently feasible with our available resources.

5. Some areas may only be able to use surge times to generate power.
When we combine tidal and wave energy options together, then it becomes possible to limit the down time of each service – but it may still limit the amount of electricity that is producible over the course of a day. There may be stalls of up to 12 hours at some locations, which means there would need to be an additional power plant somewhere that could take up the slack. Individual homes could use solar and wind to supplement their needs as well, but all of this would come at an additional cost that goes beyond the millions or billions needed for the wave energy collectors in the first place.

6. It could alter boat traffic through some channels.
When boats power through the water, they create a wake behind them that spreads out on the surface. It creates a new wave with faster motion that can eventually reach shore. The strength of this movement could be enough to overwhelm the collectors with the wave energy facility, so there would need to be restrictions on the size of the craft and the speed at which they can travel through certain areas. That means alterations to shipping traffic could become problematic in some areas for private and commercial vehicles, increasing our costs for other products in addition to the surge in pricing for the electricity that we use.

7. The movement of the water could be damaging to the equipment.
Rogue waves are a significant problem in the ocean for vessels of all sizes. These large movements are the stuff of legend, with many sailors talking about the walls of water that come toward them. These events are usually steep-sided, with a trough that becomes unusually deep. Although they are uncommon, these large waves can become destructive. The NOAA reports that the energy from multiple waves can form together to create something even larger and stronger.

The largest recorded rogue wave was 84 feet in height, striking the Draupner Oil Platform in the North Sea in 1995. In 1861, a lighthouse in Ireland was struck by a wave that had to have been at least 133 feet to create the damage that it did. In 1933 in the North Pacific, the USS Ramapo encounter a wave that the crew triangulated to be 112 feet in height. Similar events would destroy any wave energy collectors along the shore.

8. Ocean storms could damage wave energy equipment.
The conditions of the ocean could damage wave energy equipment, but so could weather events that happen above the surface of the water. Hurricanes, waterspouts, typhoons, tropical storms, and other significant events could all cause the equipment to malfunction, damage it to prevent it from working at all, or create diagnostic issues that could be costly to repair. Although storm events are more predictable than some rogue waves, there would need to be a way to protect the equipment from harm if this investment is going to pay for itself once day.

9. There can be noise issues with wave energy farms.
The waves that come crashing to the shore are often loud enough that the decibels can be bothersome to some people with sensitive hearing. The devices that collect the energy from the water movement emit a sound that some people can hear above the crashing sounds on shore. That means the installation of this technology could be disruptive visually and audibly for those who live near the devices.

The reality of wave energy collection is that it is still a developing technology, even though the idea is over 200 years old. Because it can be unsightly and loud, the other benefits that this option can provide are often overlooked since the outcome can be so bothersome to those who live or work around the collectors.

Verdict on the Pros and Cons of Wave Energy

Wave energy has the potential to help us get further away from fossil fuels as we seek out ways to transform our electrical grid and consumption habits. A 2019 U.N. climate change report finds that there are only 11 years left to prevent irreversible damage from climate change. There is a certain urgency needed by the largest countries of the world to seek out new technologies that let us continue pressing forward while looking for ways to reduce waste.

This technology would work with our current electrical grid. We could distribute power to surrounding communities with relative ease with one basic connection. Although there are costs to consider with this technology, the expense is not so much that we need to shy away from it.

The pros and cons of wave energy suggest that this technology could be the power plant of the future. Depending on how well the new facilities operate in Europe and around the world, this renewable option could be coming soon to an American coastline near you.

Author Bio
Natalie Regoli is a child of God, devoted wife, and mother of two boys. She has a Master's Degree in Law from The University of Texas. Natalie has been published in several national journals and has been practicing law for 18 years.