[Bldg-sim] WEATHER: A new free tool for creating AMY-files for Europe

[Lukas Lundström]

Dear all,

As part of my degree project I’ve developed a tool that creates Actual
Meteorological Year (AMY) files by merging observed weather data from
Integrated Surface Database (ISD) and modeled solar radiation from the
STRÅNG modeling system (developed by Swedish Meteorological and
Hydrological Institute, SMHI). Supported file formats are EnergyPlus
and IDA ICE.

Roughly, the tool covers most of Europe, excluding France (south of
Paris), Italy, Greece and everything south of that. Temporal coverage
is from Jan of 1999 to up to date for the northernmost area, the
southern area is covered from Jun of 2006.

The quality of the solar radiation data from STRÅNG varies in the
geographical dimension. Roughly the model gives good result for Sweden
and Central Europe, but underestimates for coast near areas like most
of UK, Norway etc. The model performs badly for the Baltics and some
high altitude sites as well. There’s a validation figure (for Google
Erath) at the tools homepage in the help section. Even though the
solar data from STRÅNG varies in quality it’s still better, for most
sites, than that provided in the ASHREAE IWEC files (which
underestimate direct solar radiation in the range of 20 to 40 % for
the area in question).

You are free to use the modeled solar radiation data from STRÅNG.
Weather data from ISD may however have restrictions regarding
commercial usage, depending on country and what data is being used.
Some countries have no restrictions (UK, Norway, Netherlands and
Slovenia) others some restrictions and other have most of their
weather data restricted. There is a function in the tool that excludes
data marked as “Additional” by WMO, this should make commercial use of
resulting weather files possible for most countries (my personal
interpretation of WMO resolution 40 Annex I). But it’s up to the end
user of the tool to read and interpret the WMO resolution 40 and check
with their National Weather Service for their data policy.  If
intentions are non-commercial the data accessed and created by this
tool can be used unrestricted for all countries in question.

Other issues: The STRÅNG data are on a painfully slow server so be
patient. The ISD lack recent data for many of the German weather
stations. Observed weather data can still be acquired from other
sources (i.e. EnergyPlus real-time weather service, Wunderground) and
by using copy/paste inserted into the tool. The tool has schemes for
re-sampling, interpolating and filling data gaps.

This tool was developed for making AMY-files to be used for model
calibration.  But it would be possible to use a similar approach to
create Typical Metrological Year (TMY) files as well, at least for the
North Europe where there soon exist 13 years of free solar radiation
data available via STRÅNG. Let me know if you think there’s a demand
for this kind of weather files or if you have any other comments.

Best regards,
Lukas Lundström
https://sites.google.com/site/weatherconverter