Cooperative Networks for Renewable Resource Measurements Solar Energy Resource Data

The Cooperative Network for Renewable Resource Measurements (CONFRRM) was an effort between NREL and other agencies to conduct long-term solar radiation and wind measurements at locations throughout the United States.

CONFRRM provides high-quality data for determining site-specific resources as well as data for the validation and testing of models to predict available resources based on meteorological or satellite data. The CONFRRM network provided additional geographic coverage to the National Oceanic and Atmospheric Administration's Integrated Surface Irradiance Study network.

Data Files

Access CONFRRM data files for the locations listed below. By accessing these files, you agree to abide by the NREL data disclaimer.

Prior to Jan. 1, 1996, these five CONFRRM sites together with South Caroline State College in Orangeburg, South Carolina, made up the Historically Black Colleges and Universities Solar Radiation Monitoring Network, located in the Southeastern United States:

• Daytona Beach, Florida
• Savannah, Georgia
• Itta Bena, Mississippi
• Elizabeth City, North Carolina
• Bluefield, West Virginia.

Data File Description

Solar data elements measured and reported by the CONFRRM sites include global horizontal irradiance, direct normal irradiance, diffuse horizontal irradiance, and global horizontal irradiance measured with a LI-COR pyranometer. Meteorological data include air temperature, relative humidity, pressure, wind speed, wind direction, and peak wind speed. Data logger temperature and battery voltage may also be reported. Some sites measure only two of the three broadband solar components (global horizontal, direct normal, and diffuse horizontal irradiance), while others include several meteorological measurements as well as the solar measurements.

Table 1 lists all fields that may be found in a CONFRRM data file and indicates the format for each field. Sites that include this field in their data files are also indicated in the table. For a list of measurements made at each site, and their order in the data record, see Table 2.

Data File Format

The format of the data files is comma delimited ASCII, each file containing one calendar month of quality-assessed data. Data quality assessment is performed on the broadband solar radiometric data using SERI_QC, which assigns data quality flags to every solar radiation component at every point in the data file. Flags assigned to other data indicate that the measurement passed or failed minimum/maximum tests or, in the case of a blank flag field, that no data quality tests were performed.

The following is an example of a CONFRRM solar radiation data file from Elizabeth City State University:

1997,8,1,12,0,781.21,14,821.77,15,53.02,15,27.50,01,38.88,01,30.38,01
1997,8,1,12,5,779.49,14,818.92,15,52.46,15,27.41,01,39.68,01,30.50,01
1997,8,1,12,10,779.38,14,816.37,15,52.51,15,27.24,01,41.16,01,30.48,01
1997,8,1,12,15,778.82,14,816.09,15,52.65,15,27.25,01,42.16,01,30.55,01
1997,8,1,12,20,778.53,10,814.33,11,52.61,11,26.98,01,43.12,01,30.45,01
1997,8,1,12,25,778.87,10,814.85,11,52.43,11,26.88,01,42.90,01,30.46,01
1997,8,1,12,30,778.60,14,816.57,15,53.50,15,27.00,01,42.98,01,30.36,01
1997,8,1,12,35,776.30,10,814.61,11,53.45,11,27.13,01,42.82,01,30.31,01

Each line, or record, represents five minutes, the data within each record being 5-minute averages. According to Table 2, the first field is the four-digit year, 1997. The next field represents the month, in this case, August. Next comes the day of the month, then the hour of the day, 0-23; then the minute, 0-59. Following these first five fields are the actual measured data. From Table 2, we see that in the first line the global horizontal irradiance was 781.21 W/m² and was given a flag 14 by SERI_QC.