Stormy seas: ocean power promoters struggle to overcome a stiff current of challenges

Earth Island Journal, Spring, 2009 by Larissa Curlik

The total global capacity for ocean-power generation remains unknown. But some country-specific studies show real potential. Canada could generate 25 percent of its electricity from the oceans; the UK and Portugal each could meet 20 percent of their electricity demand.

In the US, capacity drops to 10 percent, according to a study conducted by the Electric Power Research Institute (EPRI) in 2004. The report broke the number into the two primary types of ocean power: tidal (3.5 percent) and wave (6.5 percent). The numbers are theoretical, however, and the exact amount of energy that could be harnessed in the future depends largely " on the location and quantity of tidal and wave-power generators. "Society is not going to allow energy companies to build a complete line so we have no beaches at all," says Roger Bedard, who conducted the EPRI study. Assuming that projects are properly sited, Bedard believes that ocean power could be one of the more environmentally benign ways to generate electricity, even if it is not the most significant.

Riding the Waves

As the most abundant ocean-power resource, wave power has attracted the most interest and funding globally to date. "The bottom line on US ocean power," says Bedard, "is that we have significant wave resources, particularly off the Northwest and Alaska and then in Hawai'i as well."

In the US, Oregon has taken the lead in developing ocean power. In 2007, Oregon established the Oregon Wave Energy Trust (OWET), the only publicly funded organization promoting ocean power: OWET refuses to advocate for specific technologies, focusing instead on developing the industry as a whole by conducting environmental studies and making policy recommendations that promote the rapid development of ocean power.

"Wave energy is a highly reliable natural resource," says Stephanie Thornton, executive director of OWET. "It is a very clean energy and is available 24/7." Thornton predicts wave technology will also have economic benefits for the state by providing job opportunities in coastal communities. OWET's short-term goal is to generate two megawatts of power--enough to power a community of approximately 800 homes--by the spring of 2010. The long-term goal is to generate eight percent of the Oregon's energy from the ocean by 2025.

Of the companies proposing projects off Oregon's coast, Ocean Power Technologies (OPT) stands out. Based in Pennington, NJ, OPT signed a $1.7 million contract in 2007 with the US Navy for its PowerBuoy technology. The floating buoys, commonly called point absorbers, are one of the most popular types of wave-power technologies because of their relatively small size, simple design, and standard mooring system. The buoys rise and fall with the waves, and the motion turns a power take-off drive that's connected to a generator, which then transmits electricity to land via underwater cables. The company says a 30-acre ocean generating field could create 10 MW of electricity. OPT has several test sites set up off the Jersey Shore, and is planning on developing commercial fields in France, Spain, and the UK that could generate up to 100 MW.