Marine Renewable Energy: Tapping Wave and Tidal Power

Marine renewable energy harnesses the massive, predictable power of waves and tides to generate clean electricity, providing a reliable alternative to fossil fuels. Technologies such as wave energy converters (WECs) and tidal turbines have the potential to generate up to 300 GW of power globally by 2050. High energy density and predictability are key advantages, but durability and high costs continue to be difficulties.

Key Aspects of Marine Energy

• Wave Energy: Harnesses the motion of surface waves caused by wind. Technologies like oscillating water columns, point absorbers, and attenuators convert this kinetic energy into electricity.
• Tidal Energy: Utilizes the gravitational pull of the moon and sun, creating highly predictable tidal currents and ranges. Techniques include tidal barrages, which function similarly to dams in estuaries, and tidal stream generators, which act like underwater wind turbines.
• Environmental Impact: Tidal energy has very low greenhouse gas emissions, estimated at 2 g /kWh, significantly lower than other sources.
• Industry Trends: The sector is shifting towards “multi-use” platforms that combine, for instance, wave and tidal, to maximize efficiency. Projects like Core Power are deploying 5-megawatt arrays with plans to scale significantly by 2028.
• Challenges: The harsh, corrosive marine environment requires robust, durable materials and technologies, contributing to high initial installation and maintenance costs. 

Marine energy is particularly valuable for coastal regions and, with continued technological maturity, is poised to play a major role in the transition to renewable energy.

Ocean energy, the power derived from tides, waves, and currents, is an up-and-coming stakeholder in the renewable energy field. Unlike solar and wind, which are subject to climatic conditions, ocean energy is predictable and reliable. The movements of tides and waves are consistent; it is an ideal energy source to ensure a steady supply of power.

Tidal energy is surely highly predictable, hence reliably supplying energy. Tidal energy is effectively captured by turbines submerged in water. Besides, there is development of a wave energy converter that can use the energy from ocean waves to provide another form of ocean generation. These technologies are still in the early developmental stages but hold great promise for long-term energy production.

Ocean energy has a number of advantages. It does not emit harmful emissions like fossil fuels, making it an environmentally friendly option. The potential environmental impacts on marine life are relatively low when compared to traditional energy generation methods. Countries like the UK and France are already investing in ocean energy projects, positioning themselves as leaders in this emerging field.

One of the main barriers that ocean energy faces is the cost of development and installation. However, as technologies improve and scale, these costs are expected to come down. Ocean energy could help complement other renewable sources by providing a reliable and constant source of energy, filling gaps when wind or solar energy is not available.

The more investment and research that goes into it, the better ocean energy will be positioned to take a leading role in the global energy mix. This sets a very promising avenue towards clean, reliable, and sustainable energy production, thereby reducing dependence on fossil fuels and helping to meet global climate goals.

Competitive industry

Wave power is set to become cost-competitive with offshore wind by 2030s, according to a flagship study led by the two leading European universities.

Experts from LUT University School of Energy Systems in Finland, recently joined forces with the Marine Renewable Energies Lab at Delft University of Technology in the Netherlands. Their global wave energy resource assessment investigates the role of wave power in energy system analyses, incorporating real data from a state-of-the-art wave energy converter under commercialisation, and addressing a gap in the global impact that wave energy can have.

The study concludes that wave power will become cost-competitive with offshore wind power within a decade, with levelised cost of electricity below 70 €/MWh by 2035. Mid-term projections indicate wave power competitiveness with offshore wind power, suggesting a levelised cost of electricity (LCoE) below 100 €/MWh by 2030. In the 2030s, point absorber based wave power can reach a potential of 39,700 TWh of electricity for <100 €/MWh. By 2050, the LCoE could further decrease to <50 €/MWh with the potential to provide 29,000 TWh of electricity.

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Continued research and development, market growth-driven learning curves, and economies of scale will steadily reduce wave power costs, making it attractive to investors and policymakers, the researchers explain. They add that wave power can emerge to become an important source for coastal countries and regions with high population density and other factors limiting their onshore renewable energy potential, which otherwise would have to depend on energy imports.

This research was conducted as part of the EU-SCORES project.

US opportunities

The US Department of Energy’s Water Power Technologies Office has offered a US$112.5 million funding opportunity to advance the commercial readiness of wave energy technologies through open water testing and system validation. The five-year investment will significantly accelerate the design, fabrication, and testing of multiple wave energy converters.

Designed to reduce risks for deployments and increase the potential for commercial adoption through longer-duration demonstrations (expected to last six months to two years), it will also offer additional benefits to help quickly advance WECs. These include the ability to identify and mature high-potential WEC technologies, reduce financial risks for developers and incentivise investors, progress technologies at smaller scales while developing toward utility scale, and increase learning for installation, operations, and maintenance. 

This opportunity will fund projects in three topic areas:

1. Up to US$16.875 million for wave device development and open water testing for remote/offshore cases and power-at-sea applications.
2. Up to US$45 million for wave device development in direct support of coastal community needs, which may include power and/or desalinated water applications. 
3. Up to US$50.625 million for wave device development in support of utility power needs, utilising offshore, grid-connected testing facilities.

Tapping into wave energy potential

Both the potential for and challenges of harnessing marine renewable energy sources were the focal point of recent research, looking at the integration of tidal and wave energy into national power grids. Although promising strides have been made in improving the efficiency and reliability of these systems, with innovations in turbine design, materials science, and operational strategies enhancing energy conversion rates while addressing environmental impacts, the variability and intermittency of tidal and wave energy sources still present significant challenges to grid integration.

According to research by Simbolon et al, the widespread adoption of tidal and wave energy faces several challenges, including high initial costs, technological hurdles, and regulatory barriers. Addressing these will require concerted effort from researchers, policymakers, and industry stakeholders to develop efficient integration strategies and supportive frameworks.

Regulatory frameworks play a pivotal role in shaping development and deployment. Clear supportive policies that facilitate grid access, prioritise environmental sustainability, and promote stakeholder engagement are essential for fostering a conducive environment for development.

Reminding policymakers about the critical need for supportive regulatory frameworks that streamline permitting processes, incentivise investment through financial mechanisms, and prioritise grid modernisation, the research highlights the need for clear and stable policy signals to attract private sector investment, drive innovation, and accelerate deployment.

Collaboration with policymakers and researchers is essential to navigate regulatory challenges, optimise project planning, and maximise environmental and socio-economic benefits, while the authors highlight the crucial role of expanding knowledge through rigorous scientific inquiry and fostering innovation.

Tidal and wave energy represent a promising frontier in the pursuit of sustainable energy solutions, underscoring the need for continued innovation and investment in this field, Simbolon et al conclude. By integrating tidal and wave energy into national power grids, countries can reduce their reliance on fossil fuels. The successful harnessing of ocean energy not only promises environmental benefits but economic opportunities too, particularly for coastal communities, through job creation and infrastructure development. As research and development efforts continue to overcome existing barriers, the authors believes that the vision of a resilient, clean energy system powered by the sea is increasingly within reach.