New Lab Offers Mobile, Specialized Testing for Wave Energy Converter Power Take-Off Systems

A new facility at Sandia National Labs offers mobile, specialized testing for systems that produce power from wave energy.

The Sandia Wave Energy Power Take-Off (SWEPT) Lab tests wave energy converter (WEC) power take-off (PTO) systems. WECs are unique because they convert the oscillatory mechanical energy from ocean waves to generate electricity. This makes them different from other technologies that harness a relatively steady input of mechanical energy (e.g. wind turbines or hydroelectric power technologies). Because of their unique way of converting energy, WEC PTO systems require specialized methods and facilities for their design and testing.

In WECs, the power take-off systems comprise the generator and gearing stages that transform the energy of the ocean’s waves to electrical energy. Power take-off systems define key system dynamics that determine the amount of power a WEC can produce, meaning that they affect the levelized cost of energy.

“The SWEPT Lab is an exciting new capability that will allow WEC developers to test their systems before they commit to the tremendous expense of a test in the ocean or a wave tank.  This should decrease the costs and speed up the development of this promising renewable energy technology,” explained Amy Halloran, Sandia’s renewable energy technologies program manager.

The levelized cost of energy measures how much money must be made per unit of electricity (for example, per kilowatt or megawatt) for an energy project to break even. It is often used to compare different methods to produce energy, such as wind or solar power. Reducing the cost to produce energy from wave energy converters is key to their commercialization. Reducing costs, accelerating technology development, and decreasing testing and development timelines of marine energy technologies will help unleash the nation’s potential for future growth in marine energy resource extraction.

Sandia’s water power technology program leverages key research and engineering capabilities to help the emerging marine hydrokinetic industry overcome technical barriers to commercialization. This particular facility, said Peter Kobos, manager of Sandia’s water power technologies department, “allows water power developers and researchers to test their devices and tune their controls software by leveraging the national labs.  This will help industry and researchers set themselves up for successful field demonstrations.”

Although currently located at the National Solar Thermal Test Facility, the SWEPT Lab is mobile, meaning that it can be moved where it is needed or most convenient. This is important, especially when considering large systems that are meant to be assembled on site at a shipyard. Composed of five mobile units, the lab includes the test container, two generators, a power unit, control unit, and tool unit.

Prior to its commissioning, the facility completed a series of tests to characterize the system and verify that it can conduct hardware in the loop testing and system identification, or SID, testing. These initial tests have shown excellent performance.

Marine and hydrokinetic (MHK) technologies convert the energy of waves, tides, and river and ocean currents into electricity and have the potential to provide millions of Americans with locally sourced, renewable, and reliable energy.