[TRNSYS-users] Radiation; tilted surface

[David BRADLEY]

Fernando,
  Type16 can be hard to set up correctly. Make sure that you have the 
parameters for the "starting DAY of the simulation," and the "solar time 
or local time" correct. If you are using a weather data source that is 
in local time, make sure that you set the "shift" parameter correctly. 
It is also a good idea to plot the solar radiation being read from the 
data file and as processed by Type16 using a Type65 online plotter. 
Looking at the shapes of the predicted radiation curves often gives a 
good idea of potential problems in the parameters.
Best,
  David


On 11/17/2010 10:47, Sancho,Fernando wrote:
> Hello,
> I´m having some problems with the radiation data. Using the same source and,  theoretically, the same estimation models there are big differences in the results for a tilted surface between TRNSYS and the other software  we normally use, specially in winter.
> I´m using Type 16, reduced estimation from Reindl to calculate diffuse and beam components and Hay and Davies model  for tilted surface, supposed to be what the other software use.
> But basically I find  a very little change between the two different sloped surfaces , 0º and 45º. We are supposed to get much more in percent in Winter when we have a sloped surface, don´t we?
> This are the results. Latitude 52º
>
>                        TOTAL                           kWh/m2 months
> Horizontal       1011.     18.8     32.1     67.3     112.7   152.3   150.4   160.9   135.0   86.9     56.6     24.1    14.2
> 45ºSurface     1050.     22.0     38.5     79.0     122.1   146.2   135.4   149.7   138.5   100.2   72.1     29.8     6.7
>
> Any advice about it? where am I wrong?
>
> Thanks a lot
>
>
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David BRADLEY
Principal
Thermal Energy Systems Specialists, LLC
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