Tidal power is a way to generate clean, renewable energy by harnessing the rise and fall of ocean tides. Unlike wind and solar power, tidal power is predictable on a regular basis.
There are two primary ways to generate electricity using tides: there are tidal barrages, which use a dam-like structure to trap water within an estuary at high tide and then release the water through turbines at low tide. And there are tidal stream turbines, which are like wind turbines underwater that spin when tidal currents stream by.
The Department of Energy estimated that tidal energy could power 21 million homes in the US. The use of tidal power has been held back by various technical problems, such as the corrosive nature of seawater, damage to equipment caused by powerful tides, and the high cost of the technology. But even as these technical problems have continued to be addressed, the tidal power industry has been paralyzed by a lack of safety data.
A study by the Pacific Northwest National Laboratory of a tidal stream turbine running in Sequim Bay in Washington State utilized underwater cameras to observe how the system affected marine life. Schools of Pacific herring swam through the rotors; harbor seals stopped and curiously approached; diving cormorants instinctively steered clear.
An analysis of over 1,000 interactions between marine life and the tidal turbine found zero collisions for seals or seabirds, and a 98% safety rate for fish. This data could help unlock the regulatory stalemate holding back tidal energy.
