[TRNSYS-users] Time shift in result of solar radiation calculation

Agata Swierc agata.swierc at polsl.pl
Wed Aug 5 13:20:43 PDT 2015

I have some issues with the result of my simulation that I wanted to
discuss. The simulation was very basic. I wanted to calculate total and
diffusive solar radiation for different orientations and inclinations.

Orientations  -90 (east)  -- 0 (south) -- 90 (west) with inclinations  0 ,
10, 20, 30, 40, 50, 53, 60 to mimic the roofs orientations for solar panels.

I used Trnsys 16 weather data from the database IE-Dublin-Airport-39690.tm2
with the model Type109-TMY2, and connected it into the Type25a. In the
Control Cards I chose simulation start 0h, stop 8760h (one year).

In the results I saw some discrepancy because the maximum solar radiation
was for approximately hour 13:30. Dublin's latitude is 6 23W with local time
UTC, thus I was expecting the maximum to be at around 12:30.

Is it possible that Trnsys returns results in a DST time which for Dublin is
currently UTC+1?

My simulation was with time step of 1h. The maximum at 13:30 could also be
explained by wrong mapping of sample of results to the local time. Does the
first sample correspond to 00:00 1st Jan? 

Kind regards, 

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