NASA Prediction of Worldwide Energy Resource (POWER): Development of Thirty Plus Years of Satellite-Derived Solar Insolation and Meteorological Parameters for Global Applications

A significant shortcoming often associated with support decision tools is the lack of and/or the uncertainties in meteorological and solar irradiance data required as basic input to the respective application. Particularly problematic is the use of surface observations that may be far removed from the site of interest and may not reflect the environment of the application site. Additionally, surface observations can frequently have periods of missing data that need to be filled by various approximation schemes. It has become commonplace to supplement surface observations with data from reanalysis models, with a large contribution coming from remotely sensed data from satellites.

In this paper, the merits of meteorological data from NASA Modern Era Retrospective-analysis for Research and Applications (MERRA) atmospheric data assimilation and surface solar radiation derived from satellite observations (NASA's GEWEX Surface Radiation Budget [GEWEX SRB] project and NASA's Fast Longwave And SHortwave Radiative Fluxes [FLASHFlux] project) are discussed and assessed. Both the MERRA and GEWEX SRB/FLASHFLux solar irradiance data are available on a global ˝ degree latitude/longitude grid spanning the time period from January 1, 1983 to within several days of current time for the MERRA data and to within about one week for the solar data. These data are freely available as daily time series at user specified locations/regions via NASA's POWER project at http://power.larc.nasa.gov. POWER's focus is to provide satellite and modeled derived data supporting 1) Renewable Energy Technologies (RET's), 2) preliminary design of buildings and associated renewable-energy power system, and 3) agroclimatology. RETScreen International has been a big user of POWER data sets in the Renewable Energy Technologies (RET's) area. Recently, DOE/ASHRAE Building Climate Parameters has taken advantage of POWER data sets in the preliminary design of buildings via the generation of global climate zones. The agroclimatology community has also used POWER data sets for crop modeling.

The assessment of both the meteorological and the solar irradiance data are based upon comparisons with globally distributed surface observations – the meteorological observations from the National Climate Data Center's “Global Summary of the Day” (GSOD) data files and solar data from NASA's Baseline Solar Radiation Network (BSRN). Assessments of other parameters of interest such as heating, cooling, and growing degree-days are based upon MERRA vs. surface observations taken from the GSOD files. Results from the uncertainty assessments will demonstrate that the NASA's meteorological and solar irradiance data can represent a viable alternative to surface observations, particularly in data sparse regions of the world. A few applications associated with assessment of building energy usage will also be discussed.