One of the biggest untapped clean energy sources on the planet — wave energy — could one day power millions of homes across the U.S. But more than a century after the first tests of the power of ocean waves, it is still one of the hardest energy sources to capture.
“Our goal is to improve the economic viability of these devices,” said Coe. “In order to do so, we are working out ways to control the WEC’s generator to increase the amount of power it absorbs. At the same time, we are looking at how to reduce the loads and stresses on these devices in harsh conditions to ultimately lengthen a WEC’s lifespan in the water.”
Coe said numerous initial studies estimate that improving control of the WECs’ generators can dramatically increase energy absorption by as much as 300 percent. Transitioning these simplified studies to more realistic large-scale devices is the challenge at hand.
To control the dynamics for better, faster results in the wave tank, Coe and Bacelli are using modeling and control methods that have been successful in other industries, such as in the aerospace industry.
Now that Sandia has completed the first round of analyses in the water, Coe said the goal is to process all the collected data to develop a new, enhanced model that will make sure the next test yields even more valuable results.“The systems we used have been around for a while, but strangely enough they had never been applied to wave energy converters,” Bacelli said. “So far, we know the techniques we are using are more efficient and cost-effective than existing methods. We are getting more information in a fraction of the time.”
“Make no mistake, these are extremely complex machines,” Bacelli said. “They have to be fine-tuned continuously because ocean waves are constantly changing. With this setup at the Navy’s facility, we have a unique opportunity to study the problems and quantify the effects. We want to help the industry by offering solutions to the challenges the wave energy world is facing.”
Sandia’s continuing wave energy project, Advanced WEC Dynamics and Controls, kicked off in 2013 and is funded by theOffice of Energy Efficiency and Renewable Energy.
Innovations from Sandia’s Water Power Technologies Program advance our nation’s energy security by making renewable energy more economically feasible. Contributions include WEC-Sim, an open source code for modelling the performance of wave energy converters, extreme-conditions modelingand tidal and turbine modeling. Sandia researchers serve as advisers and judges for the Department of Energy’s Wave Energy Prize competition.