Meta-analysis of net energy return for wind power systems

This analysis reviews and synthesizes the literature on the net energy return for electric power generation by wind turbines. Energy return on investment (EROI) is the ratio of energy delivered to energy costs. We examine 119 wind turbines from 50 different analyses, ranging in publication date from 1977 to 2007. We extend on previous work by including additional and more recent analyses, distinguishing between important assumptions about system boundaries and methodological approaches, and viewing the EROI as function of power rating. Our survey shows an average EROI for all studies (operational and conceptual) of 25.2 (n = 114; std. dev = 22.3). The average EROI for just the operational studies is 19.8 (n = 60; std. dev = 13.7). This places wind in a favorable position relative to fossil fuels, nuclear, and solar power generation technologies in terms of EROI. (C) 2009 Elsevier Ltd. All rights reserved.