Book excerpt: The integration of renewable energy resources into the electricity grid presents an important challenge. This book provides a review and analysis of the technical and policy options available for managing variable energy resources such as wind and solar power. As well as being of value to government and industry policy-makers and planners, the volume also provides a single source for scientists and engineers of the technical knowledge gained during the 4-year RenewElec (renewable electricity) project at Carnegie Mellon University, the University of Vermont, Vermont Law School, and the Van Ness Feldman environmental law firm. The first part of the book discusses the options for large scale integration of variable electric power generation, including issues of predictability, variability, and efficiency. The second part presents the scientific findings of the project. In the final part, the authors undertake a critical review of major quantitative regional and national wind integration studies in the United States. Based on comparisons among these studies, they suggest areas where improvements in methods are warranted in future studies, areas where additional research is needed to facilitate future improvements in wind integration studies and how the research can be put into practice.