Wave Energy Conversion Modeling

NREL's open-source, validated, and customizable numerical tools enable the marine energy community to analyze wave energy conversion (WEC) power performance and predict extreme loading on the system under critical wave environments.

NREL develops free, publicly available tools to help the wave energy community analyze technology designs. The lab's customizable modeling tools can assess how much power wave energy devices could produce in various ocean sites and conditions, their potential economic performance, and how well they can weather forceful and even extremely powerful waves.

NREL also uses high-performance computing to perform more complex simulations faster. The lab's models generate highly accurate, reliable, robust data that can help wave energy devices leap from the computer screen to the ocean and, eventually, the power grid.

Research Activities

Simulating Wave Energy Device Performance

The award-winning Wave Energy Converter SIMulator (WEC-Sim), developed by NREL and Sandia National Laboratories, simulates how wave energy technology designs might perform once deployed. Developed in MATLAB/SIMULINK, the open-source WEC-Sim can model floating devices of almost any shape and size and provide precise data on how each technological component will function in waves of various heights and forces. That includes the machine's body, joints and constraints, power take-off systems (which convert wave energy into electricity), and the mooring systems that keep devices tethered in place.

WEC-Sim's comprehensive analyses can save the wave energy community time, money, and effort by exploring new designs in a low-risk, virtual environment—well before expensive, high-risk physical modeling campaigns and ocean trials. The software enables technology developers to improve their wave energy converters during the design process, potentially speeding up development. And WEC-Sim can simulate far more than wave energy technology. When paired with other modeling tools, it can analyze almost any ocean-bound device. For example, NASA recently relied on WEC-Sim to model how the Orion mission crew capsule would move in the waves after landing in the Pacific Ocean.

Modeling Extreme Conditions

NREL is also developing a framework to model extreme ocean conditions to assess how wave energy converters can handle these events. The model will help the wave energy community:

• Analyze engineering and technology designs
• Simulate technology performance
• Assess design loads.

Another NREL tool, the WEC Design Response Toolbox, includes a suite of numerical modules. These can:

• Characterize potential deployment sites in oceans and rivers across the country
• Analyze short- and long-term responses to extreme events such as storms
• Measure device fatigue over time
• Assess how specific wave heights and forces, including extreme waves, might impact technology.

Such tools can reduce uncertainty about whether devices could survive extreme conditions and, therefore, investment risk.

International Collaborations

To contribute to the global development of highly productive, low-cost, low-risk wave energy technology, NREL provides analysis and administrative support to the International Energy Agency's Ocean Energy Systems program. The lab's experts help the program assess numerical models used to analyze wave energy converters and verify their accuracy through comparisons to experimental data.

NREL's WEC-Sim team also developed and validated a WEC-Sim model of the WaveStar device for the Wave Energy Converter Control Competition organized by the National University of Ireland at Maynooth. To produce high amounts of energy for lower costs, wave energy developers must design methods to control how much energy their technology produces in different sea conditions. For this project, NREL's experts analyzed how well the WaveStar's control strategies performed in the North Sea to help developers understand how to improve these critical systems.

Publications

The Wave Energy Converter Control Competition: Overview, 38th International Conference on Ocean, Offshore, and Arctic Engineering (2019)

Design Load Analysis for Wave Energy Converters, 37th International Conference on Ocean, Offshore, and Arctic Engineering (2018)

Numerical Modeling and Dynamic Analysis of a Wave-Powered Reverse-Osmosis System, Journal of Marine Science and Engineering (2018)

International Energy Agency Ocean Energy Systems Task 10 Wave Energy Converter Modeling Verification and Validation, 12th European Wave and Tidal Energy Conference (2017)

A Survey of WEC Reliability, Survival, and Design Practices, Energies (2017)

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