One barrier to the full support and deployment of alternative energy systems and the development of a sustainable energy policy is the lack of robust conclusions about the life cycle environmental impacts of energy technologies. A significant number of life cycle assessments (LCA) of energy technologies have been published, far greater than many are aware. However, there is a view held by many decision-makers that the state of the science in LCA of energy technologies is inconclusive because of perceived and real variability and uncertainty in published estimates of life cycle impacts between and within many energy technologies. Methodological inconsistency (e.g., inconsistent system boundaries, the use of outdated data, variations on similar energy process chains, and even simple differences in reporting of results) has contributed to this impression because it thwarts easy comparison amongst published studies. Despite the depth of literature available, little attention has been focused on analyzing the results of previous research in a way that can reduce the uncertainty and variability in as-published estimates of life cycle environmental impacts. NREL’s LCA Harmonization project aims to identify the sources of and, where possible, reduce variability in previous estimates of life cycle GHG emissions from electricity generation technologies through a meta-analytical technique called harmonization. It also aims to clarify central tendency to allow for more informed decision making and the use of more robust estimates in higher order analyses. To-date, the project has collected, screened and analyzed the results of over 2000 published LCAs of electricity generation technologies, conventional and renewable. It’s results have been used in the IPCC Special Report on Renewables (featured in 10 of 12 chapters and the Summary for Policymakers) and major DOE studies. A special issue of the Journal of Industrial Ecology is being devoted to the topic of meta-analysis of LCAs where many articles developed under this project will be featured. This seminar will summarize the project and preliminary results of the harmonization of LCAs on several technologies: wind, PV, CSP, nuclear, coal and NG. It will also briefly review other related research at NREL.