The Basics of Wave Energy: Hydropower: Eco20/20

The Basics of Wave Energy

Oceans cover about 70% of Earth's surface. We use them as a source of transportation, food, and fun. Now we may be able to use them for a source of renewable energy too. The energy from waves is created by motion on the surface as well as the pressure changes below. Only some areas of the oceans are an effective source of power and scientists believe the area off the northwestern coast of the United States alone could provide a potential 2,000 terawatts of electricity. The oceans are in a constant state of motion and many scientists believe we can capture this massive energy to power our society.

Wave energy is mainly captured using one of three types of devices. The first, called the terminator, is placed in a position perpendicular to wave travel and is usually placed onshore or near shore. The second, the point absorber, creates energy through parts that move relative to each other and are powered by wave motion. The point absorber uses either an electromechanical or a hydraulic energy converter to produce electricity. The third type of device, the attenuator, is a long, many-segmented device that produces energy as it is flexed by wave motion. Aside from these devices, wave energy can also be utilized by overtopping. In overtopping, reservoirs are built to raise the water level above the surface. As this water falls back down, it powers hydro turbines, creating electricity.

All of these types of wave energy capture are currently being utilized, albeit on a relatively small scale. Why aren't we making the most of this abundant, green energy? As with any other technology, there are some concerns that must be thoroughly researched before the idea goes mainstream. First is a worry about the impact of such devices on marine habitats. There are millions of species living in ocean waters, some of which are endangered or threatened. It is important to have a complete understanding of how wave energy capture may affect these species, their behaviors, and their ecosystems before we develop widespread use of this technology. There are also concerns about visual and noise pollution, conflict with sea traffic, and potential toxic spills from devices that use hydraulic systems. All of these issues will have to be resolved before we can turn to wave energy as a real solution to the energy crisis.

Although it is not quite ready to be declared as the worldwide answer to the need for green energy, wave energy shows great potential to at least be a major contributor. With further research and development of better, safer collecting devices, it is a good possibility that we will be deriving a large portion of our energy supply from our oceans in the near future.