Public Power - January/February 2009 - (Page 27)

nd turbines are now taller and more powerful. The average wind turbine in the United States has reached the size of a mature redwood tree: a 260-foot tower, with blades extending up another 120 feet. The new machines have been stretching upward to reach the higher speed winds at greater heights, and to support a larger rotor. Since the power output of wind turbines increases by the cube of the wind speed and the square of the rotor diameter, utility-scale machines are some 200 times more productive than their predecessors in the 1980s. Today, they are rated on average at 1.6 MW, even while the product line continues to advance. The newest machines on the market are in the 2.5 to 3.0 MW range, and there is talk of 7 MW machines for offshore deployment. The modern wind industry was established in the U.S. in the 1970s, but went dormant after cancellation of the investment tax credit in 1985. Europe took the lead and manufacturing took root in Denmark, Germany and Spain. By the late 1990s, costs had plummeted, the production tax credit was put in place, and the U.S. wind industry roared back to life. The United States installed about 5,200 MW of wind power in 2007, bringing the total installed capacity to nearly 17,000 MW, about 1 percent of U.S. www.APPAnet.org Wi electric generating capacity. With the tax credit recently extended through 2009, total capacity may soon exceed 24,500 MW. Among states, Texas leads the nation in installed wind capacity. If Texas were a country, it would rank sixth in the world. It also has the largest wind farms and the most ambitious prospects for future expansion. Meanwhile, wind is growing rapidly in more than 20 states and making major contributions in several others. Wind generation accounts for more than 6 percent of the electricity produced in Minnesota, Iowa, Colorado and South Dakota. Internationally, the penetration of wind into power systems is even greater. Denmark leads the world, with wind now accounting for 19 percent of electricity generation, followed by Spain and Portugal in the 10 to 12 percent range, and Germany and Ireland in the 7 to 8 percent range. Denmark anticipates eventually moving to the 50 percent level, with a large percentage of its output destined for the European and Nordic grids. Many observers believe Europe’s more substantial experience with wind will eventually redound to the benefit of the United States. State mandates for as much as 30 percent renewable contributions within the next two decades, raises questions about just how fast and how far wind power could expand over the next 20 years. At a cost of $50 to $70 per MWh (with the tax credit), it is the most competitive of the renewable options. Could the United States emulate the wind penetration levels seen in Denmark and Spain? From 2006 to 2008, the U.S. Department of Energy spearheaded the most serious exploration of this question. DOE led a joint effort by industry, government and national laboratories, notably the National Renewable Energy Laboratory and Lawrence Berkeley National Laboratory, to establish a scenario in which wind contributes 20 percent of U.S. electricity by 2030. Their report, issued in July 2008, took a hard look at the issues, costs, challenges and impacts of this possibility, and concluded the scenario “is ambitious, but feasible, if the challenges identified in the report are overcome.” But these challenges are daunting. Supply-chain bottlenecks and limited transmission access stand as obstacles. Wind-generated electricity is manufactured remote areas, far from the urban areas that are hungry for energy. Ten years ago, the idea of expanding wind power from 1 percent of the nation’s electric generating capacity to 20 percent January-February 2009 27 http://www.APPAnet.org

Table of Contents Feed for the Digital Edition of Public Power - January/February 2009

Public Power - December 2008 Contents Perspective 10 Questions Heat or Eat? Achieving Excellence in Nuclear Operations Training Grand Ambitions for Wind Power Visions of Green Carbon Trading Across The Pond Reliability Green Energy Customer Service DEED Hometown Connections Parting Shot

Public Power - January/February 2009

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