It isn't easy harnessing the power of waves in the sea to generate electricity, but a Spanish engineering firm is giving it the ol' college try with a giant floating buoy.

Out on the Biscay Marine Energy Platform (BiMEP) off the coast of Bizkaia in Northern Spain, Bilbao-based IDOM is testing a low power wave energy converter (WEC) that's been in the works for several years now.

It's called MARMOK-A-5, and it's basically a point absorber Oscillating Water Column (OWC). It resembles a buoy with a cylindrical column of water inside, and the entire thing stands an enormous 140 ft (42 m) tall, with about 20 ft (5 m) sticking out above the surface. It's 20 ft (5 m) in diameter, and is currently anchored to the sea bed nearly 300 ft (90 m) deep.

Previous versions of this concept have been deployed over the past few years since 2016 to survive entire winters. The latest iteration features intelligent control systems, controllable blades, and onboard batteries, and is meant to demonstrate its electricity generation performance in real sea conditions.

Waves around the MARMOK-A-5 cause the water in this inner column to move relative to the buoy. This movement compresses and expands an air chamber at the top of the buoy, like a piston. The resulting reciprocating airflow spins a turbine, generating electricity that's transmitted to a grid on the shore via a subsea cable.

This version can only produce a maximum of about 30 KW of electricity, which would be enough to supply about 15-20 average US homes at its peak. Here it is at a previous deployment last year:

"Achieving a safe installation and grid connection at BiMEP is a key step towards bringing wave energy closer to commercial reality,” said IDOM project manager Borja de Miguel. This is part of EuropeWave, an EU-wide R&D program committing some €20 million (US$23 million) toward developing wave energy technologies.

Now that the MARMOK-A-5 has been successfully installed and connected to the grid as of this week, the next task is kicking it into full operational service. Data gathered from this trial will also help inform subsequent stages of fine-tuning the tech before it can be commercialized and rolled out widely.

This is far from the only WEC out on the high seas, of course. In 2024, we saw the massive 826-ton OE-25 off the coast of Oahu in Hawaii from Ocean Energy. That same year, the University of Western Australia began testing a novel WEC design in King George Sound. And back in February of this year, Denmark's Wavepiston signed an MoU to launch a 50-MW WEC installation to serve Barbados.

There's plenty of wave energy in the ocean, but creating scalable systems that can use this energy to generate electricity has proven difficult. Building them to withstand the elements out on the water, maintaining them, running them cost-effectively, and minimizing their impact on marine ecosystems all pose major challenges. Here's hoping this giant buoy gets it right.

Source: Europewave