NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. Variable Condition Pyrheliometer Comparisons 11 th International Pyrheliometer Comparisons (IPC-XI) PMOD/WRC Tom Stoffel & Joe Michalsky 27 Sept – 15 Oct 2010
National Renewable Energy Laboratory Innovation for Our Energy Future Acknowledgements Afshin Andreas Ells Dutton Pete Gotseff Bev Kay Daryl Myers Don Nelson Ibrahim Reda Steve Wilcox Radiometer Manufacturers
National Renewable Energy Laboratory Innovation for Our Energy Future Purpose Working Group on Direct Solar Measurements: Review commercially available windowed pyrheliometers relative to the BSRN goal of 3 W/m 2 accuracy Ells Dutton (US-NOAA, Chair) Klaus Behrens (GER- Deutscher Wetterdienst) Patrick Fishwick (UK Met Office) David Halliwell (Environment Canada) Don Nelson (US-NOAA) Tom Stoffel (US-NREL) Steve Wilcox (US-NREL, VCPC Coordinator)
National Renewable Energy Laboratory Innovation for Our Energy Future Experiment Design 4 Location: Solar Radiation Research Lab Golden, Colorado USA Measurement Reference: 3 All-Weather AHF Cavities (AWX) 1 Windowed AHF Test Instruments: 3 samples of each commercially available pyrheliometers. Data Collection: All readings were recorded in volts or ohms every 2 seconds, except the four cavities in W/m 2 every 1 second
National Renewable Energy Laboratory Innovation for Our Energy Future VCPC Deployment
National Renewable Energy Laboratory Innovation for Our Energy Future VCPC 24 November 2008 – 1 September 2009 Data Elements 33 Pyrheliometer Signals 1 Ref Voltage (5mV) 1 Shorted Channel Wind Speed Wind Direction Air Temperature Relative Humidity Barometric Pressure Solar Zenith Angle
National Renewable Energy Laboratory Innovation for Our Energy Future VCPC 24 November 2008 – 1 September 2009 Data Elements 33 Pyrheliometer Signals 1 Ref Voltage (5mV) 1 Shorted Channel Wind Speed Wind Direction Air Temperature Relative Humidity Barometric Pressure Solar Zenith Angle Monthly Clear-Sky Comparisons with NREL Standard Group (Un-Windowed)
National Renewable Energy Laboratory Innovation for Our Energy Future VCPC Daily Maintenance (M-F & Sa?)
National Renewable Energy Laboratory Innovation for Our Energy Future VCPC Daily Maintenance (needed today!)
National Renewable Energy Laboratory Innovation for Our Energy Future VCPC 24 November 2008 – 1 September 2009
National Renewable Energy Laboratory Innovation for Our Energy Future VCPC 24 November 2008 – 1 September 2009 Daily Maintenance (M-F) Records
National Renewable Energy Laboratory Innovation for Our Energy Future VCPC 24 November 2008 – 1 September 2009 Joe’s Analyses…