In the widening search for renewable energy sources, open water has joined the sun and wind as future energy providers. For decades, virtually all hydro-powered generation came from inland waterways, monumental projects that harnessed rivers and streams across the United States. But hydrokinetic energy can also be harvested directly from waves, as well as from the flow of tides or currents.
California’s Renewable Portfolio Standard program mandates that twenty percent of our power must come from renewable sources by the year 2010 and 33 percent by 2020, so by some standards, getting part of that power from the sea is a smart bet. The ocean is not only the largest potential source of renewable energy on the planet, but one of the most reliable, since its wave action is always “on” in a way that wind and the sun are not. Extracting energy from it produces no carbon dioxide, and a new ocean power industry could conceivably create a multitude of clean-tech jobs. All that energy “going to waste” on our northern coastline is beginning to look good to private companies hoping to exploit the waves and tides. But a tangled bureaucratic web, and a number of hard-to-answer questions about ocean energy’s impact on the marine environment, still loom in their way, and it’s made observers wonder if ocean power is worth the trouble.
The principle behind ocean power is no novelty to Californians; Sutro Baths, operated by tidal action, opened in 1896 in San Francisco. Tides pumped water uphill through canal works blasted into the rocky shore just below the north end of the Cliff House near Sutro Cove. The water emptied into six bathing tanks, with the tides capable of moving 1.8 million gallons per hour during high activity.
But using the ocean waves or tides to generate electricity is a much newer idea, and one that’s highly adaptable. Wave power can be harvested by several methods: one device looks like a regular buoy but as it bobs in the waves, it acts as a piston. Water is drawn into the center of the cylinder when a wave pushes the buoy upward. As the wave drops, the water is pressurized and forced out. The compressed water turns a turbine, which creates energy that moves from an underwater cable to the power grid.
Another means is an underwater arm that is pushed around in circles by wave action. Then there’s the Pelamis wave energy converter, which looks like an enormous chain of linked sausages floating on top of the water. Each of the “sausages” is a horizontal buoy, and power is generated in the joints between them. As the waves move the buoys back and forth, the motion of the joints is translated into power. Tidal energy, on the other hand, harkens back to those giant dams: stick a turbine in the path of the running tide and let the movement of the water spin the blades.
There are both environmental and bureaucratic impediments to ocean power, however—and opponents maintain that ocean energy’s barriers are greater than those of other renewables. Among them: it’s expensive, there’s great confusion and disparity as to the applicable licensing agencies, there’s a lack of clarity as to whether tax breaks or subsidies afforded to other renewables apply to ocean energy, and no certainty as to property rights. The last touches on a particularly prickly question: who owns the real estate, when that real estate is open water?
All these questions came into play starting in February 2007, when British Columbia-based ocean energy developer Finavera attempted to establish a pilot project off the coast of Washington state in Makah Bay. The Federal Energy Regulatory Commission (FERC) granted a conditional permit in December 2007, which was then challenged on the grounds of property rights, the Clean Water Act, the Coastal Zone Management Act, the Endangered Species Act (in particular, due to concerns about the welfare of the marbled murrelet, a threatened seabird species), tribal water quality (part of the installation is on land owned by the Makah tribe). In March 2008, FERC gave the company a preliminary go-ahead for the pilot project, but points relating to the Clean Water Act and the Coastal Management Act remained to be defined—and this is all before the environmental review.
How energy-harvesting devices might impact the ocean environment is hard to determine, since there are very few sites active in the world. Many are in Europe; the US has only a handful of experimental sites, including Makah Bay. Few of the new proposals on the table in California have made it far enough through the development pipeline to warrant environmental impact studies. When I expressed frustration with the lack of information to Sam Schuchat, council secretary of the California State Coastal Conservancy, he replied, “I think you’re having trouble finding documents because I don’t think there are any, or many. As far as I know, no ocean power proposal has gone through the [full] permitting process in this country yet, so no research has been generated.”
However, scientists are certainly already pointing out troubling possibilities. Last autumn, Oregon State University’s Hatfield Marine Science Center hosted a workshop on the ecological effects of wave energy, at which fifty scientists mulled a host of unknowns. Among the items up for discussion: the possibility of marine mammals, seabirds, large fish or turtles becoming entangled in cables, of the structures affecting fish by changing migration routes or attracting predators, of chemical pollution as paints, metals and hydraulic fluids leach into the water over time, and of the projects changing the shoreline itself by altering the water’s currents and sediment distribution.
A report summarizing the workshop’s discussion sessions outlined dozens more far-reaching concerns. For example, because power generation will create electrical and magnetic fields, it could have a disruptive effect on species like salmon, crab, rays, and sharks that rely on electromagnetic fields to navigate and find food. Additionally, the noise coming from buoys, cables or the facilities themselves could confuse or disrupt the feeding habits of animals like whales and dolphins, or become so troubling to some kinds of acoustically sensitive fish that they leave the area. The result would be a “sound barrier” surrounding the facility that animals would avoid, and that could create its own problems: the disappearance of some fish species would deprive animals further up the food chain of their prey, and gray whales that head further to sea to avoid the noise could become a better target for killer whales. Perhaps one of the most surprising species that could be affected by wave farms? Surfers. Extracting energy from waves would make them smaller as they roll in towards shore.
The OSU gathering is not the only one to have flagged concerns about ocean power. A group of policymakers and scientists assembled by the University of Cambridge in 2008 identified “disruption to marine ecosystems by offshore power generation” as one of the top 25 environmental threats to the UK of the future, along with climate engineering, controlling invasive species with engineered viruses, and nanomaterials. This April in New York, the Global Marine Renewable Energy Conference also devoted a panel to discussing environmental questions.
Even those in the ocean power business aren’t quite sure what environmental effects it could have here in California, mostly because none of them are far enough along in the proposal process to have done an environmental impact report yet. Because of the confusion over regulation and licensing, the application process has been ill-defined, to the point, says Johanna Partin, renewable energy manager at SF Environment, a city agency, that “It’s not entirely clear yet where in the process an environmental assessment should take place.”
Yet companies abroad, farther along in the scheme of things, point out that environmental impact assessments are likely to take place at the very end of the process, because they’re so expensive that they’re not worth doing until the project is a sure thing. “With a price tag in excess of 500,000 UK sterling [US $900,200] they are not undertaken until deployment becomes a reality,” says Michael Burrett of Embley Energy, Ltd, a British ocean power company that has developed a floating wave energy converter called the Sperboy, which is now moving into the full-scale prototyping stage. In addition, says Partin, “European companies have federal backing for their work, whereas here in the US there are very few federal dollars for ocean power. Our ocean power is mostly privately funded.”
Environmental questions about the local effects of wave power are likely to remain unanswered until more of the proposals for California projects work their way through the development pipeline—and it’s a very long one. Getting a preliminary permit for a hydrokinetic project entails a three-year period in which a company is allowed to perform a pilot study. During this period the permittee conducts investigations and secures data necessary to determine the feasibility of the proposed project. Wording in the permit specifically prohibits irreparable damage to the site. After the three-year period has passed, the project may be scrapped, enter yet another round of study, or go forward via application for a commercial-sized project license. The company determines the first two options, while the commercial license must be approved by FERC.
So far, preliminary permits for ocean power sites have been granted in ten US states and several others are pending. Here in California, says Roger Bedard of the Electric Power Research Institute (EPRI) in Palo Alto, “There have been six preliminary permits granted by FERC for ocean power projects in the state of California: one for tidal power in the San Francisco Bay [beneath the Golden Gate Bridge], four wave power permits out of Humboldt Bay [near Eureka], and one wave permit off the Mendocino coast [near Fort Bragg]. There have been no commercial project licenses issued in the state of California as of yet.”
Thus far, the only US commercial project license—the step after a preliminary permit—granted by FERC is to the still-disputed project by Finavera at the Makah Bay site in Washington state. A preliminary draft environmental assessment for the Makah Bay project acknowledges that development could create ecological, land use, and aesthetic conflicts, and enumerates a few pre-emptive environmental measures included in the proposal, including making sure that marine life can’t be sucked into the pressurized water flow, and putting attachments on buoys to make sure that seabirds and mammals don’t perch atop them. Yet overall, the review gives the proposed project a thumbs-up, concluding that it would not alter currents, water quality or shoreline erosion, and would not pose a danger to wildlife.
However, FERC’s permitting process is far from the only hoop to be cleared before power-generating devices go in the water. Says San Francisco’s Partin, “For the proposed tidal power project under the Golden Gate Bridge, there are an additional sixteen local, state, and federal permitting agencies that have to be applied to before we can ever start producing commercial power.”
When it comes to projects further out to sea, there may be even more regulators. FERC is currently the federal regulatory body in charge of hydrokinetic power, although the National Oceanic and Atmospheric Administration maintains control over ocean thermal energy conversion (creating energy from the movement of the ocean’s thermal layers), and judging from conference documents, NOAA wants a larger role in other ocean energy projects. Other possible players are the Army Corps of Engineers, which regulates offshore wind energy, and the Minerals Management Service, which regulates offshore oil and mineral exploration. FERC’s jurisdiction is limited to inland and near shore activity but Partin explains that there is debate about exactly where “near shore” ends. She says that the permitting procedure now being used for ocean power is based on large-scale inland hydro, which doesn’t address the ocean’s specific issues. In fact, several federal and state regulatory agencies and experts are calling for FERC to come up with a permitting process suited to ocean power.
Despite the regulatory nightmare, private companies are still lining up for a shot at what could become a very lucrative California industry. “Finavera Renewables Inc. and California Wave Energy Partners, LLC have preliminary permits for the waves coming into Humboldt Bay,” says Bedard. Utilities giant Pacific Gas & Electric is in the planning and permitting phases of a research venture called WaveConnect. “This permit is for two sites, one out of Fort Bragg in Mendocino County and the other out of Eureka in Humboldt County, where technology development companies can place their equipment for testing and showcasing and hook into PG&E’s underwater cable that connects to the grid,” Bedard explains. On September 30, PG&E received a $1.2 million grant from the Department of Energy to develop wave energy in the two North Coast counties. The project beneath the Golden Gate Bridge teams the city of San Francisco with PG&E as well as with Oceana, a tidal energy technology development company.
Just how much power can these companies harvest? Well, that’s debatable. A 2005 study conducted by EPRI raised hopes by claiming that an average of 35 megawatts of extractable tidal power flowed under the Golden Gate Bridge, enough to power around 1,300 homes. “Much to everyone’s dismay, a subsequent study conducted by the URS Corporation reported only one and a half megawatts of extractable power,” says Partin. “The large discrepancy had a lot to do with the estimates of what percent of the power could be extracted with no major environmental impacts. The original study was using between ten and fifteen percent where current estimates are closer to five. Another issue is that these estimates are site-specific. We were disappointed in those numbers, but it’s still something that the city wants to be supportive of. If we can be helping to promote ocean power and other renewables around the world, we’re still looking into it as a possible demonstration site.”
With all of the unknowns facing the new industry—the cost, the energy yield, the environmental impact—it’s hard to tell what role ocean power will play in California’s quest for renewable energy. “Is it worth it?” Partin muses. “The answer is, we don’t know yet.”
