The ISES webinar on DNI brought together several of the world experts to provide you with the most up-to-date thinking and analyses on developing credible DNI results for the CSP industry. The ISES President, Dr David RENNE, moderated the webinar. He is an expert on solar resource assessment who led the research activities related to solar resources at the National Renewable Energy Laboratory (NREL), in the USA. He currently leads the IEA Solar Heating & Cooling Task on "Solar Resource Assessment & Forecasting". The three speakers were: Dr Richard MEYER, Managing Director of Suntrace GmbH and Representative of IEA SolarPACES Task "Solar Resource Assessments & Forecasting", Germany. Dr Chris GUEYMARD, President of Solar Consulting Services, Expert on Solar Resource Assessment & Solar Radiation Modelling, USA. Dr Philippe BLANC, Responsible for Research on Evaluation of Renewable Energy Sources, Centre Observation, Impacts, Energy - MINES ParisTech, France. Speakers discussed best techniques and demonstrated operational successes in a wide variety of settings.