Frank Vignola is the director of the University of Oregon (UO) Solar Energy Center. He received his B.A. in physics at the University of California–Berkeley in 1967 and his Ph.D. in elementary particle physics at the UO in 1975. Deciding to apply his skills to more practical applications he started working in solar energy at the UO in 1977. Vignola helped establish and manage the UO solar radiation monitoring network that has the longest-running high-quality solar radiation data set in the United States. He has organized a number of solar resource assessment workshops and has written and contributed to approximately 100 papers in the field. He is currently an associate editor for solar resource assessment for the Solar Energy Journal. Joseph Michalsky is a physical scientist in the Earth System Research Laboratory within the National Oceanic and Atmospheric Administration (NOAA). Prior to NOAA he was with the Atmospheric Sciences Research Center at the State University of New York–Albany. He began his career at the Department of Energy’s Pacific Northwest National Laboratory. Michalsky received his B.S. in physics at Lamar University and M.S. and Ph.D. in physics at the University of Kentucky. His early career focused on astronomical research before taking on problems in solar energy and the atmospheric sciences. Michalsky has nearly 100 refereed publications in these fields. Thomas Stoffel manages the Solar Resources and Forecasting Group at the National Renewable Energy Laboratory. He received his B.S. in aerospace engineering from the University of Colorado and M.S. in meteorology from the University of Utah. He began his career as an aerospace engineer at the U.S. Air Force Propulsion Laboratory simulating gas turbine engine performance and infrared radiation signatures. In 1978, Stoffel joined the Solar Energy Research Institute (now NREL), where he developed the Solar Radiation Research Laboratory (SRRL) that continues to provide research-quality solar and infrared radiation measurements. Stoffel has more than 80 publications addressing solar resource characterization.