What do wave energy converters capture to generate power?

Wave energy converters capture the motion of ocean surface waves to generate power, using devices that bob and flex as swells pass beneath or through them, converting that rising and falling mechanical motion into electricity through generators built into the machine's structure. This turns the ocean's constant wave activity into a usable renewable energy source.

The saltiness of seawater is actually harnessed by a different technology, called salinity gradient power, which exploits the difference in salt concentration between fresh and salt water rather than physical wave motion. The temperature of the seafloor is not the energy source at play here either, since wave converters rely on mechanical movement, not thermal differences.

Ocean waves tend to be denser in energy and more predictable than wind, but engineers still face a major challenge in building hardware durable enough to survive years of relentless pounding from storms and corrosive saltwater.