Researchers at the National Renewable Energy Laboratory (NREL) are developing a new wave energy conversion technology with better control of wave loads in an effort to decrease the cost of renewable energy.
NREL’s ocean energy research team, led by Research Fellow Bob Thresher, came up with a different approach to wave energy device design by inventing a wave energy technology known under its record of invention title as ‘Wave Energy Conversion Devices with Actuated Geometry.’
New NREL WEC resembles a venetian blind structure pivoted at its base, and features flaps that open and close depending on wave conditions.
Each of the flaps can be individually controlled, with the ability to close fully when waves are optimal and to open to allow the excess energy to flow through.
This results in improved energy capture without overloading the generator and could cut the cost of wave energy in half, according to NREL.
“When waves are small to moderate, you can close all the flaps to maximize the wave forces and generate more power. As the wave height increases, you can sequentially open flaps to reduce the driving force and let some of the energy pass through. This allows you to operate over a wide set of wave conditions, resulting in improved energy capture while minimizing the loads, limiting the generator output,” Bob Thresher said.
Thresher’s team includes Michael Lawson, Yi-Hsiang Yu, and Nathan Tom, all of whom are among the principal developers at NREL of the Wave Energy Simulator, or WEC-Sim.
“Actuated geometry wave converters using advanced control strategies can easily cut the cost of wave energy in half by enabling better load control and power generation in a wider spectrum of sea states,” said Tom, a postdoctoral researcher who is the lead researcher on the laboratory-directed research and development wave energy project.
Thresher added that getting the wave device into the water will take some time, with a working prototype taking 4 or 5 years. “It’s truly in its infancy,” he said.