It’s risky, it’s costly, and it’s bad for the whales. But Orcas Power and Light (OPALCO) continues to pursue the feasibility of harnessing San Juan County’s robust ocean currents for power generation.
The local power cooperative recently received a $3 million U.S. Department of Energy (DOE) matching grant for its trailblazing effort to explore tidal energy as a renewable resource.
“We are looking at key issues that will be needed to line up for a project like this to move forward,” said Foster Hildreth, general manager of OPALCO, who has been looking at tidal energy since 2018. “We will need it to be financially viable and to work well in our pristine natural environment.”
Hildreth now regards “floating turbine technology” to have the most promise. A preliminary design and siting assessment, prepared under a 2021 grant from the U.S. Department of Commerce, provided OPALCO with baseline data.
The current DOE-funded feasibility study will build upon the preliminary assessment and focus specifically on the technological, environmental and economic factors underpinning deployment of “a floating stream device” currently deployed in Scotland’s Orkney Islands.
“The fundamental question is one of economics,” said Brian Polagye, director of the Pacific Marine Energy Center at the University of Washington, and a consultant to OPALCO’s preliminary assessment.
The O2 floating marine turbine
Tidal power technology relies upon the constant, highly predictable movement of oceanic tides and currents to capture the kinetic energy of moving water and convert it to electricity. OPALCO’s technology partner, Orbital Marine Energy, Ltd., has chosen to optimize underwater turbines with rotating blades mounted on a floating platform.
Orbital has been operating its O2 device in the Orkney Islands for 11 months. The 242-foot, 680-metric ton hull is anchored to the sea floor with mooring lines, suspending 50-foot rotors on “wings” mounted underneath that can be raised for on-site service.
Before the O2 or similar device could be deployed in San Juan County waters, OPALCO faces a years-long pathway for which the 2024–25 feasibility study is only the beginning. Still to come are likely further studies and an extensive interagency permitting process involving more than a dozen federal and state agencies. (Also read in Salish Current: “OPALCO proposes to harness tidal power for San Juans,” May 13, 2024.)
The preliminary assessment places the cost of building an O2-type device in the US at $40 million. OPALCO may consider placing four such devices in local waters.
“Because of the early stage of the technology, tidal power is an expensive source of energy,” Polagye told Salish Current. He cited 2019 data that placed commercial-scale tidal energy at $130 to $280 per megawatt-hour, compared to $20 per megawatt-hour for wind.
Polagye listed expensive maintenance needs for machinery in contact with corrosive seawater and pricey engineering as significant cost-driving factors. “As of now,” he added, “everything’s pretty custom.”
Conversely, he noted that, as renewable energy volumes have exploded, the “cost factors for wind and solar have plummeted.” He expects the same economic scalability would lower tidal costs over time.
Still, Polagye acknowledges that energy conservation could play a role in reducing the need for expensive solutions like the O2. “It is a lot easier to conserve than to consume,” he said.
A National Renewable Energy Laboratory study assesses the potential for rooftop solar alone to meet 39% of U.S. energy demand — 27% even in the northern latitudes of Washington. [Ed.: Corrected source.]
In U.S. waters, commercial tidal technology is in its infancy.
A study by the NREL maps four U.S. West Coast sites with potential for tidal: Washington’s Puget Sound, Oregon’s Columbia River mouth, San Francisco Bay and Alaska’s turbulent waters southwest of Anchorage.
“Harnessing just 10% of the U.S.’s tidal energy resources could be an optimistic goal even as the technology matures,” wrote Levi Kilcher, co-author of the NREL’s rooftop assessment.
Currently there are only 13 tidal installations worldwide compared to the millions and millions of available rooftops and built surfaces for solar. “They don’t need permits from a dozen state and federal agencies to operate,” said Lopez resident and energy researcher Chom Greacen. [Ed.: Corrected source.]
In 2013, the National Research Council reviewed data from DOE and raised concerns that estimates of tidal capacity could be overstated. “There’s a tendency for proponents to exaggerate the potential and not look at the practical side,” Chris Garrett, an oceanographer emeritus at the University of Victoria, noted in the study. “Things that sound green in principle are green in a small-scale situation. But even if large scale is feasible, it may not be green.”
Orbital’s $40 million O2 has less than a year of operating history with which to measure economic performance.
Critical habitat for the SRKW
The Southern Resident killer whales (SRKW) were listed as “endangered” in 2005. Few, if any, wildlife species — marine or terrestrial — seem to evoke the passions and fundamental protective instincts that the SRKW’s human counterparts feel, especially in and around San Juan County.
The passion for whales drives tourism, inspires artists, and bolsters political figures into action.
The Orcas-based scientific and educational SeaDoc Society estimates the “whale watching economy” supports over $216 million worth of economic activity in the Puget Sound annually, including generation of $12 million in state and local tax revenues, and 1,800 jobs. Whether or not the O2 itself constitutes a potential lethal hazard for individual whales, the scientific community is deeply concerned.
David Bain, chief scientist at the Orca Conservancy, is already expressing reservations about the device, even as the feasibility study gets underway. “The waters around the San Juan islands are legally designated ‘critical habitat’ for the whales,” he said. “The Southern Resident population has dropped below 75, which is dangerously close to the level from which recovery will be impossible.
“Even with access to all the habitat they have now, the population is not recovering. Further habitat loss would lead to the loss of the species, not recovery, especially if critical habitat is involved.”
Commercial ship traffic through critical habitat has exploded in recent years. Even hypothetically discounting the risk of an accidental spill of crude oil or chemicals, every ship — and there are thousands per year — removes a slice of critical habitat during its passage.
If they are in front of a ship, whales will flee. The noise and disruptions reduce hunting success. All information available to the whales tells them another segment of habitat is off limits.
The O2 is expected to be noisy. There are mechanical moving parts, hydraulics, warning signals for shipping, and more. Bain expects the O2 to be roughly the noise-equivalent of a passing commercial ship — a category of vessel already known to harm the whales’ hunting success.
“Exposure to unfamiliar noise, even if the noise source is removed,” Bain said, “can result in long-term loss of access to habitat. Further, the cumulative effects of harmful actions, no matter how small, have jeopardized the continued existence of the species.”
The O2, then, becomes one more incremental problem for the whales, 24/7/365.
“All the ways we keep chipping away at the habitat for these species, their peace and quiet, and right to live without interference,” said Elizabeth Robson of Protect the Coast PNW, which focuses on offshore energy development in the Pacific Northwest. “We just keep chipping away. Should we be surprised when that eventually tips them into extinction?”
“Agreed,” said Shari Tarantino, executive director of the Orca Conservancy. “If we continue to put obstacles in their way, including a massive tidal turbine, at some point they will be unable to adapt. We continue to put nail after nail in their coffin.”
The Salish Current is a nonpartisan, nonprofit, online local news organization serving Whatcom, San Juan and Skagit counties by reporting local news with independence and strict journalistic integrity, and by providing fact-based information and a forum for civil commentary.
