Designing wave power parks to be gentle on the ocean

The world’s oceans are a source of nearly endless clean power. Adding that power to the grid through wave energy power parks could exponentially accelerate the Green Transition and combat Climate Change. Yet the oceans are much more than a power source; they are vast ecosystems teeming with life and their health is crucial to most everything on Earth. So, at least as far as Seabased is concerned, any extraction of that clean power by wave power parks must be gentle on the ocean environment. This is one of the pillars of our design philosophy: our wave energy parks have to deliver utility-scale, cost-competitive power that is gentle on the environment.

We’re in the process of conducting a full lifecycle CO2 and environmental analysis. Here are some of the design decisions we’ve been able to make toward fighting Climate Change with naturally CO2-free, methane-free renewable wave power while protecting the ocean environment:

No turbines or blades

Algae that has grown on a Seabased generator causes no harm to the equipment and can help the ecosystem.

Seabased produces power inside a steel generator on the ocean floor. The only moving parts that sea creatures are exposed to are large buoys on the surface and the cables that connect each buoy to its generator—the Wave Energy Converter (WEC). The buoys move with the waves, raising and lowering a heavy magnet inside the steel casing of the WEC; that produces the renewable energy. There are no turbines to pull creatures in, no blades, nothing to catch or harm sea life. The large yellow buoys are as easy to avoid as any anchored boat, and tend to serve as a resting place for sea birds. Research has also showed that mussels, algae, and barnacles attach to these buoys, doing no harm to the WEC, and in some cases providing more organic matter on the seabed—food for creatures that live there.

No oils or toxins

Seabased´s wave power parks are designed to emit no chemicals. We coat the buoys and generators using solvent-free marine paints that have passed rigorous environmental testing in Scandinavia. In the past, the materials for the park included half a liter of lubrication grease (for the entire park); we designed it out.

No disturbance of the sea floor

Rather than drill into the sea floor to anchor the WECs, Seabased uses gravity. The wave energy parks are usually placed on relatively flat, barren, sandy, muddy, gravelly, or shell and pebble rock bottoms where few creatures live. We lower the WECs down to this natural ocean floor and heavy concrete bases hold them in place. We lay sea cable from the generators to the electrical converter that weaves the power of many converters, operating on different waves, into a single stream of grid-ready electricity. Another cable goes from the converter to the grid connection point on land. These cables generally settle into the sediment.

Making a home for sea life

Crab has taken up residence in a Seabased foundation.

The wave energy parks become no-fishing zones. In some areas, this has resulted in the parks serving as artificial reefs where sea life can thrive. Research has shown that that population can spill outside the parks, so the fishing industry benefits as well. We can design the bases of the generators with holes that provide a hard-walled type of shelter many animals prefer. Normally, these creatures seek out rocks or coral areas for their habitats, but they adopt these holes in the bases as their habitat. This increases biodiversity, which is essential for environmental health.

Reducing mining for materials

Wherever possible, we use recycled steel and ferrite magnets which are easily accessible and don’t require the types of mining used in rare earth metal mining—often associated with human rights violations.

Simplifying installation and maintenance

Installation of a Seabased generator

Installing equipment in the ocean requires boats, and boats use fuel. Seabased’s WECs can travel to the location where they will be installed in containers on normal cargo ships. So they don’t require specialized boats or extra burning of fossil fuels. Because the WECs are relatively small, they can be installed in a few days, using mostly smaller boats. The smaller the boat, the shorter the time, the less fuel consumed. And Seabased’s maintenance is minimal—a yearly visual inspection and switching out the electrical converters every five years. A 2MW wave energy power park has 20 generators and one converter.

What we don’t know

Research suggests that any noise or electromagnetic waves emitted from our equipment is minimal and doesn’t interfere with the normal behavior or health of sea life. Our installations are relatively small compared to the sea cables crisscrossing the oceans to carry the internet and other things.

However, this is a nascent technology, and we plan to monitor and continually improve it in terms of not only performance and cost reduction but also reduction of our impact on the natural environment.

As much as possible, we want Seabased’s wave energy parks to disappear into the coastline (although not completely for the safety of local shipping traffic). We want the energy of the ocean, that works 24/7, to be captured in a way that works—as naturally as possible—with the ecosystem, not only of the ocean but of the communities where our parks are installed.

In the changes ahead, to combat Climate Change, we must constantly revisit how the choices we’re making as a species impact the delicate ecosystems that comprise the natural balance. That’s always been Seabased’s goal and always will.

10 big advantages of smaller wave energy converters

In the world of power generation, it is often assumed that bigger is better. But building a wave energy power park, it turns out, can be an exception. Seabased has refined its Wave Energy Converters (WECs) over many years, experimenting in different ocean environments with different designs. The aim has been to create a WEC and wave park design that meets several goals:

• Get the most energy possible from a moderate ocean wave climate.

• Impact the environment as little as possible.

• Make wave energy cost-competitive with more mature renewable technologies.

The result is a modular, scaleable wave energy power park with ­­­­relatively small WECs, buoys, and a marine substation electrical conversion system that can all be efficiently transported and installed with minimal impact on the environment. In the case of Wave Energy Converters, Seabased has discovered, smaller is better. Here are some reasons why:

1. Smaller WECs extract more power from moderate waves

One of the reasons bigger seems better is that, with other technologies, it is better. With wind turbines, for example, the larger the diameter of the area swept by the blades, the more power the turbine can generate. With solar, the more panel surface you have, the more power you can collect on a sunny day. Waves, however, work differently. We’re trying to collect as much energy as possible from each individual wave – in our case, medium-sized waves of 1-3 meters height. The right size buoy will be lifted to the peak and lowered to the trough of every single wave, maximizing access to the power it packs. If it’s too large for the wave climate, the buoy could straddle the waves, and the rising action of one wave would partially cancel out the falling action of another. Consider the relative stability – and comfort – of a large ship versus a smaller boat in rough water. But we’re not looking for comfort; we want to pull the most power out of each wave. So we want the wave energy converters to be smaller.

More people live where the waves are moderate, rather than huge. The buoys of Seabased’s point absorber linear generators are designed to work best where most people live.

2. Smaller WECs provide the most stable power

Grids need power that is delivered in a steady stream. Having many smaller wave energy converters working at different times, moved by different waves, achieves a more consistent stream of power. After studying the way that waves move in a particular location, we configure our smaller WECs in an array designed to maximize the power we can extract from that wave climate. Each of the WECs’ buoys will be doing different things at any given moment. One will be on its way up, another on its way down, another just rounding off the peak of a wave. They will be moving at different speeds, with different levels of resistance, and changing instant by instant. This asynchronous movement of many smaller buoys collectively produces a more stable stream of power than if you had a few larger buoys. It is easier to make this power ready for the grid, which requires a high degree of stability.

3. Smaller WECS offer a fast track to a lower LCOE 

It’s a time-tested principle of economics: Every time you double production of a thing, the cost of production drops, because you grow more efficient with repetition. This learning curve is often in the area of 80%. So if the first 20 units of a product takes 100 hours to make, the next 20 should only take 80 hours; the following 20, 64 hours; the next batch 51 hours…until you’ve reached maximum efficiency. The costs drop as efficiency rises. This accounts in part, for the low Levelized Cost of Energy (LCOE) achieved by many mature renewables today. With small WECs, more must be produced to create a power park, leading to a rapid learning curve and dropping costs.

4. Smaller WECs make for scaleable wave parks

Our modular, plug-and-play wave energy parks are designed so that wave park customers can start small, if they like, and scale up as needed.

5. Smaller WECs can be shipped with a smaller environmental impact

Seabased has designed its components so that they can be shipped in containers, which means that standard cargo vessels can move them along with other goods. This greatly reduces the carbon footprint of transportation for installation, relative to a large device that requires special transport.

6. Smaller WECs can be installed and maintained with smaller vessels

Because of their size, Seabased can use smaller work boats to install a wave energy park. Wind power parks tend to need much larger vessels because their power depends on long blades that create a larger diameter.

7. Smaller WECs can be installed quickly and sustainably

An entire wave park can be installed in only a few days, from wave to grid. And, because the WECs are small, no drilling, mooring, or other seabed preparation that could harm the environment is required. Their concrete bases are enough to anchor them to the sea floor. This means less cost and better outcomes for the ocean environment and ecosystem.

8. Smaller WECs mean more local jobs

With smaller WECs, it becomes easier to find facilities that are capable of building or assembling components locally. This means wave energy parks create local jobs. Very large components require facilities and transports that are unavailable in many places.

9. Smaller WECs make good neighbors

Coastal areas are prime real estate. Fishing, shipping, tourism, all compete for space in coastal areas. A wave power park needs utilize an area with optimal waves that will have the least impact on other local ocean stakeholders. Seabased’s smaller WECs are virtually invisible from the shore. This makes them good neighbors in area where ocean views are an essential part of a coastline.

10. An array of Smaller WECs can make the most of the waves

Before installing a wave energy park, we conduct extensive feasibility studies to understand, among other things, how waves move in that particular location. Because of latitude, climate, topography of the sea floor (bathymetry), and other factors, the length and shape and regularity of the waves will be a little different in each place. With smaller WECs, we have more flexibility to fine tune the arrangement of the wave park array to make the most of each wave climate.

Seabased arrived at its conclusions about size with a lot of testing and experimentation. But now, as we work toward the certification of our technology, we’re increasingly appreciative that size does matter—in our case, smaller is better.

Seabased to speak at Sustainable Energy for Africa Conference

Seabased CEO Laurent Albert and Energy and Environment Manager Francisco Francisco PhD are honored to have been asked to speak at the SE4A 2021 conference to be held in Cotonou from 08 thru 11 November 2021.

 The two will present together on aspects of wave energy in Africa including:

• The advantages of West Africa’s moderate and steady wave climate in producing electrical power

• How the predictability of wave can offset some of the intermittency issues experienced with other African renewable sources

Access to energy is essential to growth and development around the world, and many African nations have eagerly embraced renewables as part of their strategy for future growth. The wave climate in West Africa, though less vigorous than in Northern Europe, is very steady and could produce significant amounts of electricity year-round. Seabased wave energy technology has already been tested offshore near Ada, Ghana.

Sustainable Energy for Africa is an international conference organized jointly by the Benin National Academy of Sciences, Arts and Letters (ANSALB) and by the Royal Academy for Overseas Sciences of Belgium (KAOW-ARSOM).

 Laurent Albert joined Seabased as CEO in 2019. He is a French civil engineer and MBA who has previously held senior executive positions in Europe and Asia in both high-end tech and marine renewables in Naval Group (formerly DCNS), Naval Energies, and TechnipFMC.

Francisco Francisco has a PhD in Electrical Engineering and conducts feasibility studies for Seabased’s commercial wave energy parks. Originally from Mozambique, and now a resident of Sweden. Prior to joining Seabased in 2017Francisco was a research fellow with OceaNET - Marie Skłodowska-Curie Actions where he developed hardware based on sonar systems for sub-sea environmental monitoring.