Christian A. Gueymard received a PhD from the University of Montreal, Canada. He has held the position of research scientist at the Florida Solar Energy Center and is currently president of Solar Consulting Services (USA). He has been active in solar energy applications for 45+ years and developed an internationally recognized expertise in the fields of solar resource assessment, solar radiation modeling, radiometry, and their applications in various technological forms of energy production. His solar radiation models are widely used in solar applications. In particular, various ASTM and IEC spectral irradiance standards are based on his SMARTS model. He has published 220+ scientific papers in refereed journals or conference proceedings, as well as 30+ research reports or book chapters. He has received awards from ASHRAE, ASME, and ISES for his excellence in publication and from ASES for his career achievements in support of the solar energy industry.