Andy Walker is a Senior Research Fellow at the National Renewable Energy Laboratory, where he conducts engineering and economic analysis of energy efficiency and renewable energy projects for Federal agencies such as national parks and military bases and also for commercial and industrial clients. He has lead photovoltaics training and certification efforts in Ghana and Tanzania and has experience with off-grid PV/battery/generator installations for applications such as cell phone sites. His patent on the Renewable Energy Optimization (REO) method of planning renewable energy projects across a portfolio of properties based on economic value was awarded the Thomas A. Edison Patent Award in 2015 based on innovation and impact. He has taught at the University of Colorado at Boulder, Colorado School of Mines, and at Metropolitan State University of Denver. He has led the Solar Energy Division of the American Society of Mechanical Engineers and is an ASME Fellow. Dr. Walker is the author of over 28 book chapters, journal articles, and conference papers including “Solar Energy: Technologies and Project Delivery for Buildings,” a reference book published by John Wiley and Sons; and “Sustainable Energy Technologies,” by CRC Press. Dr. Walker’s credentials include a B.S., M.S., and Ph.D. in Mechanical Engineering from Colorado State University, and he is a registered Professional Engineer in the State of Colorado.