Solar Energy Lab Weather Data

Most transient thermal simulations require weather data. The Solar Energy Lab has begun the process of collecting weather data and making it available to the simulation community. The TRNSYS simulation program, developed by the Solar Energy Lab, is capable of accepting many forms of weather data. However, two primary types have been standardized. The first is monthly average data, which is available for download below. The second format is TMY (Typical Meteorological Year) data. Each TMY file contains one year of weather information at one hour time intervals for a particular location.

The SEL has generated weater hourly data for cities throughout the world. The data is in TRNSYS TMY format. List of Cities

Monthly Average Weather Data

The TRNSYS Type 54 Weather Data Generator generates hourly weather data for a typical year given the monthly average values of solar radiation, dry bulb temperature, humidity ratio, and windspeed (optional).

WDATA.DAT is a file of monthly average weather data from 329 sites in the United States and Canada. The data is taken from the publication Input Data for Solar Systems by Cinquemani, Owenby, and Baldwin, published by the U.S. National Oceanic and Atmospheric Administration, Asheville, NC.

NREL.DAT is also a file of monthly average weather data from the 239 US sites listed in WDATA.DAT. This file is from the National Solar Radiation Data Base (NSRDB) created by the National Renewable Energy Laboratory (NREL). This file should be more accurate and current than the data in WDATA.DAT.

Monthly average weather data in the files WDATA.DAT and NREL.DAT is listed in the following format: 

line 1: NLOC
line 2: LOCATION 1	 LATITUDE
line 3: I1  I2  I3 ... I12
line 4: w1  w2  w3 ... w12
line 5: TEMP1 TEMP2 TEMP3 ... TEMP12

line 6: LOCATION 2	LATITUDE
line 7: I1  I2  I3 ... I12
ETC.

where:

NLOC: the number of locations in the data base
LOCATION: the name of the location, maximum of 32 characters
LATITUDE: between -90.0 and 90.0 degrees, number must start in column 33
I1-I12: monthly average daily global horizontal solar radiation (kJ/m2)
w1-w12: monthly average humidity ratio multiplied by 104 (kg water / kg air)
TEMP1-TEMP12: monthly average temperature (degrees C)

See the section 4.1.10-1 of the TRNSYS Manual for more information.

Typical Meteorological Year (TMY) Data

TRNSYS TMY Data

TMY data sets for 234 U.S. locations, derived from the widely accepted 1952-1975 SOLMET/ERSATZ data base, have been modified at the Solar Energy Laboratory for ease of use with the TRNSYS energy system simulation program. The original TMY files are ASCII text files containing one year of weather data (ranging from solar radiation to precipitation) at one hour time intervals. TRNSYS TMY files, containing only the most widely used information from the original files and corrected for known problems, are available from the Solar Energy Lab. These files are much smaller in size than the original TMY files from which they are derived.
 
TMY2 Data
 
TMY2 weather files for 239 U.S. locations can be downloaded free of charge from from the U.S. National Renewable Energy Laboratory (NREL). The TMY2 data are derived from the 1961-1990 National Solar Radiation Data Base (NSRDB). As TMY2 data are based on more recent and accurate data and will make possible more accurate performance and economic analyses of energy systems, these data sets are recommended by NREL for use in place of earlier TMY data sets derived from the 1952-1975 SOLMET/ERSATZ data base. TMY and TMY2 data sets cannot be used interchangeably because of differences in time (solar versus local), formats, elements, and units. The TMY2 data sets and manual were produced by the National Renewable Energy Laboratory's (NREL's) Analytic Studies Division under the Resource Assessment Program, which is funded and monitored by the U.S. Department of Energy's Office of Solar Energy Conversion.

Links to Other Weather Resources

Current Madison, WI Forecast from WISC-TV3

Interactive US Weather Map (University of Hawaii)

Solar Energy Resource Maps from NREL: