This book resLilted from the recognition that, for wind energy to continue its success and worldwide growth, policy makers and industry practitioners must understand the complex interplay of factors affecting wind energy today. These factors include not j List technology and economics, but also issues of policy, finance, corn-petition and environment. We have written this book with three primary audiences in mind: policy makers, academic researchers and electricity industry professionals, For energy policy makers and energy industry analysts, the hook should be useful for understanding how the wind energy industry has arrived at its current state, what have been the tactors for success as well as failure, and, most importantly, what are the critical factors which will affect its future evolution and implementation.