Ok. Based on cloud information from the weather files, or?
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Dru Crawley <dbcrawley@...> wrote:
>
> The EnergyPlus WeatherConverter now does calculate direct/diffuse solar
> radiation if it's missing.
>
>
> On Thu, Nov 8, 2012 at 9:47 AM, rokkas80 <lukas.rokka@...> wrote:
>
> > **
> >
> >
> > E+ don't model the solar radiation by it self. You need to have weather
> > files with measured or/and modeled values. But E+ may have some simple
> > "sanity check" (like that there shouldn't be any solar radiation during
> > night time and min/max limits).
> >
> > --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "Jean marais" <jeannieboef@>
> > wrote:
> > >
> > > no. i mean from latidute and longitude and the equation of time, etc.
> > together with some assumptions about atmospheric conditions, the direct and
> > diffuse radiation can be calculated. It does not have to be measured, or?
> > If there was no weather data for this, or incorrect weather data...I was
> > under the impression that e+ runs a "sanity check" to see if the radiation
> > from weather files is okay. And if not, it uses it's calculated results?
> > I've made a excel spreadsheet once to do this as a check...and the results
> > are okay.
> > >
> > > --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "rokkas80" <lukas.rokka@>
> > wrote:
> > > >
> > > > I don't understand what you are asking for, could you please clarify?
> > > > Do you mean that e+ calculates the direct normal solar from global and
> > diffuse solar? Well, the Weather Converter program can calculate the direct
> > normal from global and diffuse solar according to the documentation.
> > > >
> > > >
> > > > --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "Jean marais" <jeannieboef@>
> > wrote:
> > > > >
> > > > > "Even though the solar data from STR�NG varies in quality it's
> > still better, for most sites, than that provided in the ASHREAE IWEC files"
> > > > >
> > > > > Doesn't e+ calculate the direct solar?
> > > > >
> > > > > --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "rokkas80" <lukas.rokka@>
> > wrote:
> > > > > >
> > > > > > Hi all,
> > > > > >
> > > > > > I've updated my tool for creating Actual Meteorological Year (AMY)
> > files for North Europe. The tool can be downloaded at
> > http://rtwc.blob.core.windows.net/clickonce/publish.htm.
> > > > > >
> > > > > > News for this version, Real-Time Weather Converter 2.0:
> > > > > > - All data from ISD is available, also data marked as
> > "Additional". If you tried the tool before but didn't get any data for your
> > station, you should now be able to get usable data for most locations.
> > > > > > - A new server that maps data from the SMHI server. Now retrieval
> > time are just a few seconds for one year of solar data. A AMY-files can now
> > be made in under a minute.
> > > > > > - Missing data points are visualized graphically.
> > > > > >
> > > > > > The tool was made as part of my MSc degree project at
> > M�lardalens University, Sweden. It uses observed actual weather data from
> > the Integrated Surface Database (ISD),
> > http://www.ncdc.noaa.gov/oa/climate/isd, and modeled solar radiation data
> > from STR�NG, http://strang.smhi.se.
> > > > > >
> > > > > > Roughly, the tool covers most of Europe excluding south Europe.
> > Long-term coverage is from 1 of January 1999 to up to date for the
> > northernmost area, the southern area is covered from 1 of June 2006 (see
> > website for map).
> > > > > >
> > > > > > The quality of the solar radiation data from STR�NG varies in
> > the geographical dimension. Roughly the model gives good result for Sweden
> > and Central Europe, but underestimates for ocean coast near areas like UK,
> > Norway etc. The model do underestimate as well for the Baltics, northern
> > Finland and some high altitude sites. There's a validation figure (for
> > Google Earth) at the tools homepage in the help section. Even though the
> > solar data from STR�NG 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). For model calibration these data are very useful.
> > > > > >
> > > > > > You are free to use the modeled solar radiation data from
> > STR�NG. Weather data from ISD may however have restrictions regarding
> > commercial usage, depending on country and what data is being used. Some
> > countries (UK, Norway, Netherlands, Slovenia and Sweden from next year(?))
> > have free weather data, other countries some restrictions and some
> > countries have most of their weather data restricted. There is a method 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
> > freely for all countries in question.
> > > > > >
> > > > > > 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 methods for re-sampling, interpolating
> > and filling data gaps.
> > > > > >
> > > > > > This tool was developed to make 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 geographic
> > area where there soon exist 13 years of free solar radiation data available
> > free via STR�NG. Let me know if you think there's a demand for this kind
> > of weather files or if you know of any available tools or algorithms that
> > can make this kind of files.
> > > > > >
> > > > > > Best regards,
> > > > > > Lukas Lundstr�m
> > > > > > https://sites.google.com/site/weatherconverter
> > > > > >
> > > > >
> > > >
> > >
> >
> >
> >
>
------------------------------------
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