The wave motor represents an early attempt to harness tidal power and turn it into useful forms of energy. These motors were common in California in the late 1800s and early 1900s, and can be considered precursors to more modern tidal power initiatives. The first wave motors were developed without the intent of generating electricity. Mechanical energy created by these motors was used to run pumps, mills, and other devices. The specific technology used by each wave motor differed, though a common practice was the use of wave motion or tidal movement to pump seawater up into reservoirs and then allow it to flow back down and rotate various generators and other devices in the process.
Patents were first issued in the United States for wave motor devices in the late 1870s, and many different projects were created in the following decades. There were two predominant types of wave motor designs, the first of which depended somewhat on the natural landscape. These wave motors utilized tunnels and wells that were drilled into cliffs. Wave power could then be used to pump seawater into the well, which could be used as a sort of catchment basin. The seawater would then be channeled downhill and used to operate devices mechanically or turn dynamos.
The other kind of wave motor depended largely on man made constructions. These motors were often built out on piers, and some were quite large. The wave motion was still typically used to power pumps, and some of the same principles were employed to operate hydraulic generators and other devices. Some of these massive constructions collapsed into the ocean, while others were abandoned and have since become buried under the sand.
Early wave motors were built without the thought of generating electricity, as electrification did not begin in countries such as the United States and other industrialized nations until the mid 1880s. These early motors harnessed wave motion for many of the same purposes that hydraulic power had been used since antiquity. The potential energy of wave motion was typically used to operate mills and other mechanically powered devices.
Later wave motors took full advantage of electrification and sought to provide electric power to coastal cities. Instead of operating mechanical devices, the hydraulic power of these motors was used to turn dynamos in much the same way that generator turbines are operated in modern hydroelectric dams. Though the technology has changed in the intervening years, wave power is still used to generate electricity. The first modern wave farm was built in Portugal and began generating electricity in 2008. Similar projects have also been proposed or constructed in areas such as the United States and the United Kingdom.