Wave energy is emerging as one of the most promising yet underutilised renewable sources. Tapping into the rhythmic, predictable power of ocean waves, this technology offers a clean, reliable alternative to fossil fuels and a valuable complement to wind and solar energy. With oceans covering over 70% of the Earth’s surface, the sheer scale of this resource is immense. If effectively harnessed, wave energy could meet a significant share of global electricity demand, especially for countries with long coastlines.
The engineering promise of wave energy
Unlike solar or wind, wave energy is far more consistent. Waves are not as subject to daily or seasonal fluctuations, making it a more reliable form of generation. The density of water also means wave energy has a much higher power potential per square metre than either solar or wind. However, the engineering challenges are equally significant. Devices must operate in corrosive saltwater environments, withstand storms and minimise impact on marine ecosystems.
Wave energy converters come in a variety of forms − point absorbers, oscillating water columns, overtopping devices and attenuators, to name a few. These systems convert the kinetic and potential energy of waves into mechanical motion and then into electricity. Progress in materials science, control systems and offshore construction methods is making them more robust, efficient and cost-competitive.
Mutriku Wave Power Plant
Spain’s Mutriku Wave Power Plant, located in the Basque Country, represents one of the most successful and longest-operating commercial wave energy projects in the world. Commissioned in 2011, this plant cleverly integrates oscillating water column technology into a breakwater structure in a dual-purpose design that protects the harbour while generating clean energy.
The Mutriku facility houses 16 air turbines, each powered by the rise and fall of seawater in enclosed chambers. As waves move in and out, they push air through the turbines, generating electricity. While the 300 kW power output is modest by utility standards, the significance lies in its continuous operation and the lessons it offers in system reliability, turbine design and grid integration.
The Mutriku plant demonstrates how wave energy infrastructure can be embedded into existing coastal developments. This reduces environmental impact and construction costs, offering a scalable model for other ports and coastal cities. “We’re not just generating electricity, we’re proving that wave power can be part of everyday infrastructure,” says project engineer, Iker Goiria.
Carnegie Clean Energy
In contrast to surface-based devices, Australia’s Carnegie Clean Energy developed a fully submerged wave energy technology known as CETO, named after a Greek sea goddess. Situated off the coast of Western Australia, CETO units are tethered to the seabed and operate several metres below the surface, making them invisible, storm-resistant and less intrusive to marine life and shipping.
Each CETO buoy moves with wave motion, driving hydraulic pumps that send pressurised water ashore through subsea pipelines. This high-pressure water is then used to generate electricity via a conventional hydroelectric system or to produce freshwater via desalination.
Unlike wind and solar, which require separate systems for water treatment, the CETO system combines both energy generation and desalination into a single compact, modular platform. “The ocean is relentless, so our technology has to be just as resilient,” says the lead CETO designer at Carnegie Clean Energy.
Scaling up
Wave energy is still in the early stages of commercial development and scaling up is a major challenge. High capital costs, harsh offshore conditions and limited deployment experience have slowed its adoption. Additionally, unlike wind or solar, there are few standardised technologies, with developers often having to come up with proprietary designs.
Nevertheless, governments and private investors are beginning to take notice. The European Union has set ambitious marine energy targets, with wave energy expected to contribute to a more decentralised, resilient energy mix. The USA Department of Energy is investing in test facilities like the PacWave site in Oregon, which aims to accelerate the commercial viability of marine energy technologies.
Emerging synergies with offshore wind farms, aquaculture and hydrogen production also make wave energy increasingly attractive. Shared infrastructure such as subsea cables and platforms can reduce costs and environmental footprints. Hybrid systems that combine wave, solar and wind could also offer continuous, balanced power generation in changing weather conditions.
A blue horizon
With countries struggling to meet their Net-Zero goals, wave energy offers an opportunity to diversify the renewable energy mix. Despite the hurdles, the potential benefits − predictable output, coastal job creation and technological innovation − are too significant to ignore. With supportive policy, continued R&D; and smart integration into existing maritime infrastructure, wave energy could play a role in the global shift towards sustainability.
For more information visit www.mutriku.eus/en/tourism/mutriku/olatu-planta
© Technews Publishing (Pty) Ltd | All Rights Reserved
printer friendly version