Unique electrical system turns inputs of many waves, generators working at different speeds, into one stream of power for the grid
Wave power technology company Seabased is optimizing its precision electrical system that channels inputs from many generators - each absorbing power from different waves - into a single stream of electricity that is ready for the grid.
To get a sense of the system’s complexity, the way it operates is loosely similar to a traffic system that can respond to individual cars and manage a seamless traffic flow through an intersection at incredible speed – maximizing that flow by the millisecond.
“The electrical system is unique in its ability to passively channel the power from multiple generators through the right inverters at the right instant to create a single stream of grid-ready power,” explains Anders Kronberg, Seabased’s lead electrical engineer.
The Seabased electrical system is housed in a Marine Substation (MSS) on the ocean floor, where it is connected to an array of linear generators. Each generator has a cable leading to a buoy on the surface. The buoys move with the waves, and this motion lifts and lowers magnets called translators inside the generators, producing power. In a standard array, 20 generators will transmit to one MSS. Though the power comes in asynchronously, from several different waves happening at different times, the MSS converts all these inputs into a smooth stream of 33kv DC grid-ready electricity. From the MSS, standard sea cables deliver this electricity to the grid.
What makes the electrical system’s job more complicated is that the power varies in voltage, depending on how fast the translator is moving and where it is in the journey up and down inside the generator when the wave hits. In addition, the generators are carefully spaced so as catch different waves, so no two generators are producing power the same way at the same time. When these disparate inputs from multiple generators arrive at the electrical system, they need to be carefully channeled in a way that produces the optimal stream of electricity at any given time.
Fine tuning for a variety of wave climates
This system must work non-stop, 24 hours a day 365 days a year, channeling the power generated from an endless parade of waves. “Optimizing the system entails finding the sweet spot where the generators and the electrical system work together to maximize output without risking excessive wear and tear,” explains Kronberg.
Almost paradoxically, part of what makes the electrical system original is that the components that make up the system are off-the-shelf. “This is critical because it both saves costs and secures stable access to supply,” according to Seabased CEO Laurent Albert.
Seabased is currently working with organizations such as the University of Edinburgh and ENAG, a French energy conversion company, to ensure the electrical system is fine-tuned to extract the maximum power in a variety of wave climates.
“Our business model is wave-to-grid, not just providing a technology that turns waves into power, but providing whole systems that we can design, build, and install in communities to provide grid power from waves,” explains Albert. “This optimization is part of the roadmap.”