[TRNSYS-users] Info weather forecast in Trnsys

[David BRADLEY]

Toni,

  I am not aware of a component that will read ahead in a weather data 
file. You could of course modify Type15 to do so (or write your own 
component to do so). You might also be able to run a simulation in which 
you read the weather data and write back out the critical pieces of it 
that you want (ambient temperature and solar). Then modify that file so 
that it is shifted by 24 hours. From then on you can use a Type9 to read 
the shifted weather data in parallel with whatever component you're 
using to read the present weather data. There are components available 
that will give you a running average over the past N hours. Because the 
data is shifted, what it thinks of as the "past" N hours are in fact the 
"next" N hours.

  If you do this, be careful not to run the shifted solar data through a 
radiation processor (such as Type16) but instead deal only with the raw 
(uninterpolated) data. The reason is that Type16 uses the present 
simulation time to determine the sun's present position. If you run the 
modified solar through a radiation processor you'll be using tomorrow's 
data with today's sun position.

  Also a slight caution in that you're going to get a perfectly accurate 
"forecast" of the next day's weather. Once or twice in my experience I 
have seen days when the forecasted weather did not turn out quite the 
way it was supposed to. You might want to add some stochastic element to 
your forecast so that it is not always 100% accurate. There are some 
random number generator components in the TESS Utility library that can 
help in this regard (though not directly)

kind regards,

  David



On 06/30/2022 10:16, Toni Calabrese via TRNSYS-users wrote:
>
> Hi,
>
> for a project we are interested on weather forecast analysis in ordert 
> o increase PV self consumption. I would like to understand if  there 
> is the possibility (with a Type?) to calculate in Trnsys average 
> values of variables (ambient temperature or solar irradiation) looking 
> in the future (24h+ for example). What I would need is in each 
> timestep to have the possibility to compare a variable with the 
> average of that variable considering the next N timesteps. Someone 
> could help me?
>
> ------------------------------------------------------------------------
>
> *Toni Calabrese*, MSc.
>
> Wissenschaftlicher Projektleiter
>
> toni.calabrese at spf.ch <mailto:toni.calabrese at spf.ch> 
> |toni.calabrese at ost.ch <mailto:toni.calabrese at ost.ch>
>
> T +41 58 257 4827
>
> SPF Institut für Solartechnik
>
> OST – Ostschweizer Fachhochschule
>
> Oberseestr. 10 | CH-8640 Rapperswil | Switzerland | www.spf.ch 
> <http://www.spf.ch/>| www.ost.ch <http://www.ost.ch/>
>
>
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-- 
***************************
David BRADLEY
Principal
Thermal Energy System Specialists, LLC
3 North Pinckney Street - suite 202
Madison, WI  53703 USA

P:+1.608.274.2577
d.bradley at tess-inc.com

http://www.tess-inc.com
http://www.trnsys.com
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