NREL Releases Updated Typical Meteorological Year Data Set
May 1, 2008
The U.S. Department of Energy?s National Renewable Energy
Laboratory (NREL) today released an updated typical
meteorological year (TMY) data set derived from the
1991-2005 National Solar Radiation Data Base update. The
TMY3 data and user?s manual are available at
http://rredc.nrel.gov/solar/old_data/nsrdb/1991-2005/tmy3
The new data sets update and expand the TMY2 data sets
released by NREL in 1994. The TMY3 data sets provide greater
geographical coverage than previous TMY sets with
information on 1,020 locations in the United States, project
leader Steve Wilcox said. Only 239 locations were listed in
the TMY2 data set.
A TMY data set contains typical meteorological values for
specific locations. TMY data sets are widely used by
building designers and others for modeling renewable energy
conversion systems. Although not designed to show
meteorological extremes, TMY data sets hold hourly values of
solar radiation and meteorological elements for a one-year
period that typify climate based on a much longer period of
time.
Unless they are revised, computer programs designed for
previous TMY data sets will not work with TMY3 data. NREL
provides a software utility that allows reformatting of the
TMY3 data to the TMY2 format at the TMY3 link above.
The TMY3 data sets and the users manual were produced by
NREL's Electric and Systems Center under the Solar Resource
Characterization Project, which is funded and monitored by
DOE?s Energy Efficiency and Renewable Energy Office.
NREL is the U.S. Department of Energy's primary national
laboratory for renewable energy and energy efficiency
research and development. NREL is operated for DOE by
Midwest Research Institute and Battelle.
For further information contact NREL Public Relations at
(303) 275-4090.
Jason Glazer, P.E.
Great news on the TMY3 weather data. We want to start using it in eQuest.
However, FYI... in order to test the new TMY3 files out, we downloaded a TMY3
weather file for Little Rock, AR. Then we converted the TMY3 file to TMY2
(using same name as TMY2 --> LITTLEAR.BIN ), placed it in a new folder under
eQuest weather (Weather\TMY3) then tried to use in eQuest and got an error,
and the simulation would not run.
Is there any additional information that we need to know in order to make
this work?
Any information would be appreciated.
Thanks!
Regards,
James A. Hess, PE, CEM
Be aware that what NREL calls TMY2 weather data is true text based TMY2
weather data per their original definition. DOE2 (eQuest) uses a binary
version of the TMY2 weather files. The binary version is about 1/10th
the file size of the original text based TMY2 file. You need to use
another weather processor to convert the true TMY2 into a binary version
(xxxxxx.BIN) for use with eQuest. You can't just rename the file as it
sounds like you did.
step 1 - Get the TMY3 weather file for your location
step 2 - Use NREL's TMY3toTMY2 converter to convert it to TMY2
step 3 - Use DOE2 or EnergyPlus weather utilities to convert the text
based TMY2 weather file to a binary version for use with DOE2 (eQuest)
I think you skipped step 3.
Randy Wilkinson
Randy,
I very much appreciate that information!
Thank you
Regards,
James A. Hess, PE, CEM
I am attempting to follow these steps, but I can't seem to figure out how to use the DOE2 unilities. It looks like it is only DOS based and I am not familiar with DOS. Could you walk me through the steps to convert from .TM2 to .bin using the DOE2 utility?
Thanks,
Tim
Be aware that what NREL calls TMY2 weather data is true text based TMY2
weather data per their original definition. DOE2 (eQuest) uses a binary
version of the TMY2 weather files. The binary version is about 1/10th
the file size of the original text based TMY2 file. You need to use
another weather processor to convert the true TMY2 into a binary version
(xxxxxx.BIN) for use with eQuest. You can't just rename the file as it
sounds like you did.
step 1 - Get the TMY3 weather file for your location
step 2 - Use NREL's TMY3toTMY2 converter to convert it to TMY2
step 3 - Use DOE2 or EnergyPlus weather utilities to convert the text
based TMY2 weather file to a binary version for use with DOE2 (eQuest)
I think you skipped step 3.
Randy Wilkinson
I've just gone through this procedure, i.e., creating *.BIN versions, for 50
of these new TMY3 weather files, using the TMY3toTMY2 and doewth programs.
Please note that doewth reads only a 5-number station number, while these
new TMY3/TMY2 files use a 6-number station number. Thus, you need to delete
the last number from the station number both on the INPUT.TMP and the first
line of the raw TMY2 weather file.
Joe Huang
The DOE2 documentation is a little confusing in this regard. Here are
the general steps:
1. Copy your TMY2 file to DOE2's EXENT directory and rename to
WEATHR.TMP
2. Create a file called INPUT.TMP in the EXENT directory
3. In the INPUT.TMP file, put the following text. Be sure to replace the
city, state, and station number as appropriate for your location. You
can find this information in the first line of the TMY2 file.
PACK
PHOENIX AZ TMY2
TMY2 23183
STAT
END
4. Run the DOEWTH.EXE executable (it will automatically use the
WEATHR.TMP and INPUT.TMP files above as inputs). This will create a
NEWTH.TMP file in the EXENT directory that is your bin weather file for
use with DOE2. Just rename to Location.bin and you're set.
Scott Horowitz
As I mentioned in a previous BLDG-SIM post yesterday, you must change the
station number from 6 numbers to 5 in both the INPUT.TMP file and the first
header line of the TMY3/TMY2, i.e., WEATHR.TMP, file. If you don't, you will
either get a warning that the station number in the INPUT.TMP is too big, or
another one that the station number doesn't exist on the WEATHR.TMP file.
Joe Huang