Wave Energy Could Provide Electricity

As the world's supplies of readily-available oil, natural gas, coal, and uranium continue to be depleted, there is greater urgency to find clean and sustainable sources of alternative energy. Currently the most favored candidates are solar and wind, but they have still-unresolved weaknesses: In most parts of the world, sunshine and wind are intermittent; solar panels require considerable surface areas, and have yet to reach high levels of efficiency; wind turbines are even larger in length, expensive to build and maintain, prone to failure, and blamed for killing birds. Moving these energy collectors offshore can solve many of these problems, but would end up creating new ones.

Perhaps we should be looking offshore, but in a different manner. Any surfer or sea captain can attest to the awe-inspiring power of the ocean's waves, and energy researchers have for ages dreamed of harnessing that power to generate untold amounts of electricity — nonpolluting, continuous, and unquestionably superior to burning petroleum-based fuels. The ocean, even at its calmest, has powerful swells. Water is far more dense than air or ultraviolet radiation, and thus provides far more energy in the same space — thus allowing correspondingly smaller energy collection devices versus those needed for wind and solar. A recent article published by Smithsonian.com details some of the key issues. It is estimated that, for the United States, wave power could provide roughly 6.5 percent of present electricity needs, according to Roger Bedard of the Electric Power Research Institute of Palo Alto, California. It would equal approximately the same amount of power currently produced by all US hydroelectric dams, or 150 million barrels of oil — what is consumed by 23 million average American homes annually.

Yet over the years, the technical challenges of developing viable wave-energy converters, have proven daunting, largely because of the number and complexity of the converters' components: tubes, hoses, couplings, bearings, valves, filters, switches, gauges, meters, sensors, and more. The failure of just a single component could easily mean the failure of the entire device. Engineers have long known that a much simpler design was needed. Annette von Jouanne, an electrical engineer at Oregon State University, is working with colleagues at the Wallace Energy Systems & Renewables Facility (WESRF) to develop and eventually perfect just such a design, with only two major components. The first, shaped like a large post, contains a thick coil of copper wire, and is anchored to the seabed. The other is a large magnetic ring, encircling the first, attached to a float that moves vertically, driven by the waves. The motion of the two components relative to one another generates electricity. In fact, the current prototype can generate three kilowatts — enough to power two homes.

This pioneering and promising research is just the beginning, and we may one day look to the oceans as our primary source of electrical energy.