TOF algorithm

Dear all,

I am trying to find optimum tilt angle with ladybug by using TOF component.

is it necessary to know what is inside the TOF and which formulas are used for estimating total annual solar radiation as well as the optimum tilt angle. But the problems are the formula inside the TOF. EPW gives us 8760 hours data file that feeds into the diffuse and direct and ground-reflect solar radiation. but, it is not clear that we used all 8760 hours data or average the data for a whole year or....?

and second questions is there is no any azimuth parameter inside the formulas. And how mesh is created without considering any azimuth parameter (see picture below).

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Replies to This Discussion

Permalink Reply by Hamid on July 23, 2016 at 12:05am

And why I can not create the figure for ground reflected values by bar chart component but I can do it for beam and diffuse solar radiation (see picture below please)?

and If I use just azimuth =180 degrees and different values for tilt angle, the results for annual solar radiation (2074 kwh/m2) will be the same as values that calculated for each azimuth and tilt angle?

thank you.

Permalink Reply by Hamid on July 23, 2016 at 12:39am

diffuse

Permalink Reply by djordje on July 23, 2016 at 2:56am

The reason why you got that error when you plugged the Eground to the Monthly bar chart component is due to bug inside the Monthly bar chart component.
The first branch of the Eground data tree consists of ground-reflected values for tilt = 0.
The PV_SWH_surface can not "see" beyond its plane, therefor a surface parallel to the ground does not receive any ground-reflected radiation. So all values are 0.
It would be useful to inform the user that the annual hourly values supplied to the _inputData are all zeros, instead of raising an error.
I will report this to component's author.

Are you trying to plot the total monthly values of beam, diffuse and ground-reflected, and total solar radiation?
For example in January the beam component was 100 kWh/m2 total (the summation of each hourly value in January).
In February the beam component was 120 kWh/m2 total, and so on...
Because right now with Monthly bar chart component you are plotting values for each hour during a year separated into months.

and If I use just azimuth =180 degrees and different values for tilt angle, the results for annual solar radiation (2074 kwh/m2) will be the same as values that calculated for each azimuth and tilt angle?

I didn't understand you this. Can you clarify please.

Permalink Reply by Hamid on July 23, 2016 at 3:32am

I am trying to plot both total monthly and yearly values of beam, diffuse, ground-reflected as well as total solar radiation (at azimuth = 180, tilt angle=0-90 degrees).

Permalink Reply by djordje on July 23, 2016 at 4:14am

I added a new output to the TOF component: Epoa, which would represent the total incident radiation on PV_SWH_surface (summation of Ebeam, Ediffuse, Eground). Monthly bar chart component does not support visualization of annual values, so you can not view those. In the attached file below you can only preview monthly values.

Attachments:

TOF_Eb_Ediff_Eground3.gh, 548 KB

Permalink Reply by Hamid on July 23, 2016 at 4:43am

Can I render each plot separately at Rhino?

In grasshopper, is it possible to plot total monthly values of incident radiation (x-axis) and tilt angle (y-axis) ?

thank you

Permalink Reply by djordje on July 23, 2016 at 4:57am

Can I render each plot separately at Rhino?

You probably can, but you need to google on how to render the mesh colors.
A simpler solution would be to use the "Print Screen" button on your keyboard, instead.

In grasshopper, is it possible to plot total monthly values of incident radiation (x-axis) and tilt angle (y-axis) ?

It is possible.
You can for example use the grasshopper Conduit plugin, or send the annual numerical values of Average Data component's totAnalysisPeriod output to Excel and make charts there.