Extreme conditions modeling is an essential step in the design process of wave energy converters (WECs) to accurately predict how the devices will respond to wave overtopping, large motions, and wave slamming.
Sandia’s water power technology group will provide critical expertise in computational modeling to companies on the forefront of the emerging marine hydrokinetics industry, thanks to a $10.5 million award from DOE. The award will help six US companies improve the design and operation of wave energy converters (WECs) to harness clean, renewable energy from waves, tides, ocean currents, and the natural flow of water in rivers. Marine and hydrokinetic systems are a largely untapped industry that has the potential to power up businesses and homes across the nation’s coastal regions.
Sandia research engineer Ryan Coe is the principal investigator on the extreme conditions modeling project. Ryan and researchers from Sandia’s water power technology group will partner with National Renewable Energy Lab to provide numerical modeling solutions, a framework to help companies design systems that can survive harsh marine conditions.
Ryan says, “It is exciting for us to take this research to another level of fidelity and detail by working with these private companies on their WEC devices. The hope is that our work will not only benefit them, but that we also will learn a lot of important information in the process which gets cycled into our knowledge at Sandia.”
One of the challenges these companies in the emerging wave energy field face, Ryan says, is that wave tank testing is expensive. Sandia’s modeling resources will save them time and money, he says, by equipping them with loads of data to help limit their time in the wave tank and make better usage of the time spent there.
What are extreme conditions in WEC modeling? Contrary to what comes to mind, Ryan says it is not always defined as one big wave, like a tsunami. It is a set of conditions that causes major stress on the device. “The ocean is a really random place made up of waves that are constantly overlapping each other. So to analyze an extreme condition, we might look at a series of somewhat smaller ocean waves that are set up with just the right spacing to come along and clobber the device,” Ryan says.
Along with the extreme conditions modeling project, Sandia’s water power technology group is well underway with phase 1 of experimental testing on Wave Energy Converter SIMulator (WEC-Sim), a numerical modelling project testing at Oregon State University’s Hinsdale Wave Research Laboratory. WEC-SIM, an open source code for modeling the performance of wave energy converters, begins phase 2 of testing in the spring.
Both projects contribute to the nation’s energy security by making wave energy more economically feasible.