Wave and Tidal Renewable Northwest Project
Total Page:16
File Type:pdf, Size:1020Kb
Wave and Tidal Renewable Northwest Project experience in the field, WAVE AND TIDAL ENERGY IN THE NORTHWEST “Oregon and Washington adequate R&D funding, have the best wave energy Total Annual U.S. Incident Wave 2,110 terawatt- and proactive public pol- resource in the lower 48 Energy hours icy support, the costs of states … and could eventu- wave and tidal technolo- Technology: Wave Energy Tidal Energy ally generate several thou- gies are expected to fol- Current Levelized ~10-30 ~8-12 sand megawatts from wave low the same rapid de- power.” Cost (2006$) cents/kWh cents/kWh crease in price that wind Future Levelized ~5-6 cents/kWh ~4-6 cents/kWh energy has experienced. plore construction of North Amer- Cost (2006$) ica’s first utility-scale wave energy Potential facility off the coast of Reedsport, Resource Type Variable, Variable, highly Worldwide potential for Oregon. With the support of the predictable predictable wave and tidal power is Oregon Department of Energy, Ore- enormous, however, local kWh = kilowatt-hours. 1 terawatt-hour = 1 billion kWh. gon State University is also seeking Sources: see endnote 1. geography greatly influ- funding to build a national wave en- ences the electricity gen- ergy research facility near Newport, What Is Wave and eration potential of each technology. Oregon. Several tidal power projects Tidal Energy? Wave energy resources are best be- are also being explored in the region. In addition to its abundant solar, wind tween 30º and 60º latitude in both Tacoma Power has secured a prelimi- and geothermal resources, the Pacific hemispheres, and the potential tends nary permit to explore a tidal power Northwest is also uniquely situated to to be the greatest on western coasts. project at the Tacoma Narrows, one capture the renewable energy of the The United States receives 2,100 of the best locations for tidal power in ocean. Special buoys, turbines, and terawatt-hours of incident wave the country, and Snohomish County other technologies can capture the energy along its coastlines each year, Public Utility District has received power of waves and tides and convert and tapping just one quarter of this preliminary permits for seven other it into clean, pollution-free electricity. potential could produce as much potential tidal power sites in the Like other renewable resources, both energy as the entire U.S. hydropower Puget Sound.4 wave and tidal energy are variable in system. Oregon and Washington nature. Waves are produced by have the strongest wave energy re- Wave Energy winds blowing across the surface of source in the lower 48 states and Technologies the ocean. However, because waves could eventually generate several There are three main types of wave travel across the ocean, their arrival thousand megawatts of electricity 2 energy technologies. One type uses time at the wave power facility may using wave resources. Several sites floats, buoys, or pitching devices to be more predictable than wind. In in Washington’s Puget Sound with generate electricity using the rise and contrast, tidal energy, which is driven excellent tidal resources could be de- fall of ocean swells to drive hydraulic by the gravitational pull of the moon veloped, potentially yielding several 3 pumps. A second type uses oscillat- and sun, is predictable centuries in hundred megawatts of tidal power. ing water column (OWC) devices to advance. While no commercial wave or generate electricity at the shore using The technologies needed to gen- tidal projects have yet been devel- the rise and fall of water within a cy- erate electricity from wave and tidal oped in the United States, several lindrical shaft. The rising water energy are at a nascent stage, but the projects are planned for the near fu- drives air out of the top of the shaft, first commercial projects are cur- ture, including projects in the North- powering an air-driven turbine. rently under development, including west. AquaEnergy Group, Ltd is cur- Third, a tapered channel, or over- some in the Pacific Northwest. Like rently designing and permitting a topping device can be located either most emerging energy technologies, one-megawatt demonstration wave on or offshore. They concentrate wave and tidal technologies are cur- power plant at Makah Bay, Washing- waves and drive them into an ele- rently more expensive than traditional ton. Ocean Power Technologies has vated reservoir, where power is then generating resources, but with further received a preliminary permit to ex- generated using hydropower turbines Renewable Northwest Project • 917 SW Oak St., Ste. 303, Portland, OR 97205 • Phone (503) 223-4544, Fax (503) 223-4554 • www.rnp.org • revised 3/07 Wave and Tidal Energy page 2 as the water is released. The vast ma- flow spins the turbines, which then jority of recently proposed wave en- generate electricity. Tidal turbines ergy projects would use offshore would be deployed in underwater floats, buoys or pitching devices. ‘farms’ in waters 60-120 feet deep The world’s first commercial off- with currents exceeding 5-6 mph. shore wave energy facility will begin Because water is much denser than operating by the end of 2007 off the air, tidal turbines are smaller than Atlantic coast of Portugal. The first wind turbines and can produce more 7 phase of the project, which Scottish electricity in a given area. A pilot- company, Ocean Power Delivery scale tidal turbine facility – the first (OPD) developed, features three in North America – was installed in ‘Pelamis’ wave energy conversion New York’s East River in December devices and generates a combined 2006. The developer, Verdant 2.25 MW of electricity. OPD plans Power, hopes to eventually install a 8 to expand the facility to produce 22.5 10 MW tidal farm at the site. Graphic: Artist’s representation of an MW in 2007.5 Environmental underwater tidal turbine. (Source and copyright: Marine Current Turbines, Ltd.) Tidal Power Impacts Technologies Unlike fossil-fueled power plants, Power Delivery (Nov 2006). Until recently, the common model for wave and tidal energy facilities gen- -Tidal energy levelized costs from North tidal power facilities involved erect- erate electricity without producing American Tidal In-Stream Energy Con- ing a tidal dam, or barrage, with a any pollutant emissions or green- version Technology Feasibility Study, sluice across a narrow bay or estuary. house gases. Since the first wave and EPRI (June 2006), pgs 5-6. As the tide flows in or out, creating tidal energy facilities are currently 2 EPRI op. cit. note 1, p 28. uneven water levels on either side of being deployed, the full environ- 3 “Tides hold promise of electricity.” The the barrage, the sluice is opened and mental impacts of wave and tidal Daily Herald (Everett, WA), 2/11/07. water flows through low-head hydro power remain uncertain but are pro- http://www.heraldnet.com/stories/07/02/1 turbines to generate electricity. For a jected to be small. Concerns include 1/100loc_a1sunpower001.cfm. tidal barrage to be feasible, the differ- impacts on marine ecosystems and 4 “Current Projects”, AquaEnergy Group, ence between high and low tides must fisheries. Environmental impact Ltd. (2006), http://aquaenergygroup.com/ be at least 16 feet. La Rance Station studies are currently underway and projects/index.php, accessed 10/18/06. in France, the world’s first and still several pilot and commercial projects -“Agreement to Develop Wave Park in largest tidal barrage, has a rated ca- are undergoing environmental moni- Oregon”, RenewableEnergyAccess.com, pacity of 260 MW and has operated toring. The East River tidal turbine 2/23/07, http://www.renewableenergyac- since 1966. However, tidal barrages, pilot project includes a $1.5 million cess.com/rea/news/story?id=47546&src= have several environmental draw- sonar system to monitor impacts on rss, accessed 4/2/07. backs, including changes to marine fish populations, for example.9 Care- and shoreline ecosystems, most nota- ful siting should minimize impacts on - The Daily Herald, op. cite. note 3. 5 bly fish populations.6 marine ecosystems, fishing and other “Energy Portugal: Riding the Wave of the Future”, InterPress News Agency, Several other models for tidal coastal economic activities. Wave 9/27/06, http://ipsnews.net/news.asp? facilities have emerged in recent and tidal facilities also have little or idnews=34898, accessed 10/19/06. years, including tidal lagoons, tidal no visual impact, as they are either 6 fences, and underwater tidal tur- submerged or do not rise very far Renewable Energy Fact Sheet, Envi- ronmental and Energy Study Institute, bines, but none are commercially above the waterline. (May 2006). operating. Perhaps the most promis- 7 Depth and current speed requirements ing is the underwater tidal turbine. 1 Wave energy resource figure and from “Background”, Marine Current Several tidal power companies have graphic from: Project Definition Study: Turbines (MCT), (2002), developed tidal turbines, which are Offshore Wave Power Feasibility Dem- http://www.marineturbines.com/backgrou similar in many ways to wind tur- onstration Project, Electric Power Re- nd.htm, accessed 10/17/06. bines. These turbines would be search Institute (EPRI), (Jan 2005), p 12. 8 The Daily Herald, op. cite. note 3. placed offshore or in estuaries in -Wave energy levelized costs from corre- 9 “Energy From the Restless Sea”, New strong tidal currents where the tidal spondence with Des McGinnes of Ocean York Times, 7/3/06. Renewable Northwest Project • 917 SW Oak St., Ste. 303, Portland, OR 97205 • Phone (503) 223-4544, Fax (503) 223-4554 • www.rnp.org • revised 4/07 .