 The Power of the Ocean - By Ken Silverstein Daily IssueAlert 3/22/2004 Free Sitting oceanside can be tranquil, but harnessing the force of the tides and waves can be a powerful experience. As the world's largest solar collectors, the oceans generate thermal energy. Now the task before scientists and engineers is how to capture this energy and produce electricity. The primary advantage of this technology is its energy density. Sea water is 832 times as dense as air, providing a six mile per hour ocean current with more kinetic energy than a 217 mile per hour wind, says Devon Girard, an expert with Blue Energy, an ocean energy developer. Ocean currents are one of the largest untapped renewable energy resources, he adds, noting that research shows a potential global market of 450,000 megawatts. That market would be worth more than $550 billion. European Union officials say that by 2010 ocean energy will generate more than 950 MW. To make ocean energy economics work, it will need to be done on a large scale basis. France's La Rance station is the only industrialized-sized tidal power station—gates and turbines are installed along dams—in the world. The plant, which went on line in 1966, produces 240 MW. The Annapolis Royal Station in Nova Scotia, Canada, meanwhile, generates about 20 MW of power using tidal power. The largest proposed system would be a 2.4 mile network in the Philippines that is estimated to cost $2.8 billion and should produce 2,200 MW. That so-called tidal fence uses turnstiles that spin with tidal currents but has been delayed because of political obstacles. Blue Energy of Canada is commercializing a turbine that generates electricity from ocean currents. It has developed six prototypes that produce up to 100 kilowatts. The cost: $1,200 per kW, it says. The tidal fence, which acts like underwater windmills, allows water and marine life to flow through freely and safely. The company says that in the United States, the Florida currents and the Gulf Stream are reasonably swift and that the continuous currents move in areas where there is a high demand for power—a key requirement if ocean currents are to be developed as energy sources. The United Kingdom could also be a potential spot for ocean power. A proposed off-shore project near Lynmouth would be capable of producing 300 kW of electricity and will become a testing ground for other tidal turbines. Project developer Marine Current Turbines told the BBC that it hopes the deal will come to fruition soon and added that tidal power could produce 10 gigawatts of power in the United Kingdom. “That's about the same as the existing nuclear industry,” it told the news organization. Indeed, it's a powerful concept, adds Richard Longini, a Ph.D. in physics. Ocean currents are reliable and the infrastructure required to harness its power is unobtrusive. Typically the ocean current streams are 80 to 150 kilometers wide and are most rapid near the surface, he says. They extend downward 80 to 120 meters. The fastest currents near the surface are about 2 meters per second. To get some idea of magnitude, he says that the total water flow in the Gulf Stream alone is about 30 times that of all the rivers on earth. Site Selection Altogether, the U.S. Department of Energy says that there are only a few hundred land-based sites in the tropics where deep-ocean water is close enough to shore to make ocean energy feasible. At the same time, ocean energy does present environmental challenges. According to the Energy Department, tidal power plants can impede sea life migration and can affect local ecosystems. Newer technologies, however, are less problematic and don't block migratory paths. The optimal solution, it says, is careful site selection. That involves appropriate spacing of the plants and choosing sites that preserve scenic shorelines. The economics of such facilities is also proving to be an impediment. While it doesn't cost much to operate tidal plants, they are expensive to build and any return on investment would take a long time. The cost of a proposed tidal power plant in the Severn River in the United Kingdom, for example, is estimated to run $12 billion for a 10 gigawatt facility—far more costly than a fossil-fired plant. As a result, the cost per kWh is not as competitive, says the Energy Department. In the United States, the Energy Department is funding one such ocean energy project in the Gulf Stream 11 miles off the Florida coast that would produce 120 kW. Because of the significant capital expense required to build tidal power plants, the private sector is reluctant to get involved right now. That could change if the price of coal or natural gas rises dramatically and stays there. And, it could change if governments decide to get more involved. That said, the cost to produce such power is coming down and the cost to operate those plants is nominal, given that the seawater is free. That's why the San Francisco Department of the Environment is looking into placing a generator hundreds of feet under water near the Golden Gate Bridge. Meanwhile, ocean energy has other positive attributes. “The power output of generators may not easily be incorporated directly into power grids but it could produce hydrogen gas which could be used 'on shore' to produce power,” says physicist Longini. “It might be the optimum way for the present hydrogen enthusiasm to be put into effect.” Obviously, harnessing the power of the ocean is a fledgling concept. But, scientists and engineers are working hard to figure out ways to bring the idea into the mainstream. If they are successful, then ocean energy could become another arrow in renewable energy's quiver. UtiliPoint's IssueAlerts are compiled based on the independent analysis of UtiliPoint consultants. The opinions expressed in UtiliPoint's IssueAlerts are not intended to predict financial performance of companies discussed, or to be the basis for investment decisions of any kind. UtiliPoint's sole purpose in publishing its IssueAlerts is to offer an independent perspective regarding the key events occurring in the energy industry, based on its long-standing reputation as an expert on energy issues. Copyright 2004. UtiliPoint International, Inc. All rights reserved. |
