From Energy Bulletin
Energy Quiz: What renewable fuel delivers the most net energy?
by John Gulland

Charles Hall, a professor in the Faculty of Environmental and Forest Biology at the State University of New York, is one of the foremost EROEI researchers. Below is a graph produced by Hall and his colleague John Day that was published recently in American Scientist. The tan colored parts of the bars represent the range of EROEI resulting from different source quality and processes. The figures along the x axis show the exajoules of energy supplied in the U.S. by each of the sources