According to a new U.S. Department of Energy Report, wave and tidal power have the potential to produce 15% of the electricity that the United States demands by 2030. The United States uses about 4000 TWh of electricity per year . Their reports show that wave and tidal power have the potential to produce about 1420 TWh annually. The west coast has a very high potential for producing wave energy, while the east coast has strong tidal power that can produce energy for coastal areas. The report bases its predictions with a study that uses “10 MW, 15 MW, and 20 MW per kilometer as alternating scenarios and takes the middle one as a base case, given the current state of technology”.
Figure 1: Map of US wave energy resources – National Renewable Energy Laboratory 
An interesting technology that can harness the wave energy is the Voith Hydro Oscillating Water Column (OSC). The system works by generating power along the coast as waves oscillate back and forth. The water goes into an opening in the water chamber that is below the water level. As the ocean waves oscillate the water level inside the chamber rises and falls. The rising water compresses the air in the chamber and forces it through a turbine, generating electricity. When the water falls the air in the chamber expands and is sucked back into the water chamber, going through the same turbine again in the process. The turbine is a Wells turbine, which is a “low pressure air turbine that rotates continuously in one direction in spite of the direction of the air flow”. The plant has entered commercial use in Mutriku, Spain. This plant uses 16 Wells turbines and has a nominal capacity of 300 kWh. Below is a video that further illustrates the plant’s function.
While the scale of this plant is small, it is encouraging to see that an OSC plant is feasible; perhaps developers of this plant can build something on a larger scale. Also, as we move forward and form a better understanding of this form of energy, the technology will only get better and we will see capacities increase dramatically.