There has been some debate about whether wind turbines have a more limited shelf-life than other energy technologies. A previous study used a statistical model to estimate that electricity output from wind turbines declines by a third after only ten years of operation. Some opponents of wind power have argued that aging turbine technology could need replacing en masse after as little as ten years, which would make it an unattractive option in economic terms. In a new study, researchers carried out an analysis using local wind speed data from NASA, and showed that the turbines will last their full life of about 25 years before they need to be upgraded.