A bevy of bright-yellow buoys may soon bob off the coast of Reedsport, Oreg. With each rise and fall of an ocean swell, the flotilla of giant, robotic, $4 million duckies will generate electrons to power TVs and industries. The electricity will travel to an underwater substation, then by cable to shore. What impact will these plunging machines – humming with electromagnetic fields, strung together by a network of cables – have on the marine environment? No one's really sure.
Such is the gist of a new report prepared for Congress by the Department of Energy. Much of the report, which explores the possible impacts of energy generators on marine and aquatic environments, is necessarily speculative, pointing out a fathomless list of side effects surmised from related, existing situations, like traditional hydro-electric turbines, offshore wind farms, bridge construction, and so on.
Over 100 different "marine and hydrokinetic" renewable energy technologies are in the conceptual stages – the farm off the Oregon Coast, with 10 buoys planned by 2012, is set to become the first in the US. Such projects, which come in all shapes and sizes, could change currents, amplify or diminish or redirect waves, scar ocean floors, grate across endangered grasses, shift sedimentation patterns, host possible biofoulers like mussels and algae, create buzzes and clicks and rings harmful (or surely irritating) to marine mammals, cause a racket while being installed, introduce many less-than-wonderful toxins (feel free to skip ahead at any time), entangle leviathan flippers, effectively erect walls and block migrations, suck fish into vortices, knock them silly (or in two) with rotating blades ... (exhausted and stressed out yet?).
Of course, the report also points out that many of these worries might not pan out, nor prove insurmountable, particularly with scrupulous planning. Situating buoys and other floating generators to avoid sensitive or especially biologically productive pelagic, estuarine or riverine zones — and installing them during the right season — will go a long way toward minimizing their eventual impact. Overall, the report emphasizes the need to closely monitor these technologies and their impact as they are implemented, then make adjustments as appropriate. In essence, the best of strategies: common sense.
What's also notable, perhaps, is that the report focuses only on the impact this wave of the energy future might have on marine and aquatic environments, saying nothing of human use conflicts (such as the concerns of commercial fishermen), aesthetics, viewsheds, etc. Though not the purview of DOE's report, these issues are undoubtedly some of the more important stumbling blocks that will have to be negotiated before marine and hydrokinetic energy can get off the ground, and into the water.
For more on tidal energy in the Northwest, check out this HCN feature: "Testing the Waters"