FONTE: ECONOMISTDATA DA NOTICIA: 04/12 /2008Energy: Wind power has established itself as an important source of renewable energy in the past three decades. The basic idea is ancient, but its modern incarnation adds many new high-tech twists.Old-fashioned windmills, no longer used to grind flour, have become tourist destinations in much of the developed world. Most people would agree that wooden windmills fit pleasingly into the landscape, and are charming reminders of a simpler, agrarian past. But opinion is divided about their high-tech descendants, wind turbines, which are springing up across the world as a source of renewable electricity. To some they are a blight on the landscape; to others they are graceful, majestic structures that signal the shift towards new sources of energy.The first wind farms sprouted in California in the early 1980s, beneficiaries of generous tax credits. Among the rolling hills of Altamont Pass, near San Francisco Bay, some early turbines can still be seen spinning, turning a portion of the winds kinetic energy into electricity. With capacity of mere tens of kilowatts and a rotor diameter of 15 metres or so, these windmills are no giants, at least by todays standards. New machines typically have a capacity of 1.5-2.5 megawatts (MW), or 30 to 50 times that of the early Altamont Pass turbines, with rotor diameters as great as 100 metres, so that their blades sweep an area about the size of a football field.document.write('');The wind-power industry has come a long way since the first Altamont Pass turbines started to spin. Although wind generates only about 1% of all electricity globally, it provides a respectable portion in several European countries: 20% in Denmark, 10% in Spain and about 7% in Germany. Wind power is also on the rise in America, where capacity jumped by 45% last year to reach nearly 17 gigawatts (GW) at the end of 2007. In China the pace has been faster still. Since the end of 2004, the country has nearly doubled its capacity every year. Globally, wind power installations are expected to triple from 94GW at the end of 2007 to nearly 290GW in 2012, according to BTM Consult, a Danish market-research firm. They will then account for 2.7% of world electricity generation, the company predicts, and by 2017 their share could be nearly 6%.LINK: http://www.economist.com/science/tq/displaystory.cfm?story_id=12673331COMENTARIO: O artigo apresenta de forma rapida um resumo da evolucao do mercado de energia eolica nas ultimas 3 decadas. A partir do inicio do anos 70, com a segunda crise do petroleo em 1973, os paises perceberam que nao podiam deixar as suas economias a merce do preco do petroleo. Notadamente os paises com base industrial e grande dependencia de importacao de petroleo, tais como Alemanha, Espanha, Dinamarca e Estados Unidos, comecaram a investir em pesquisa para desenvolvimento de tecnologia para geracao de energia eolica. A primeira usina eolica comercial conectada a rede publica foi instalada em 1979 na Dinamarca. A partir dai, em alguns paises como Alemanha, os governos passaram a dar incentivos que permitiram que a industria se desenvolvesse, ganhasse escala e atraisse investimentos do setor privado.No