Hello,

I saw some threads related to this on old forum and github but didn’t fild an answer. There is this great example file that changes lightning schedule according to recieved daylight. The drawback would be analysis time here as Daysim, even on low settings, would take a while. This may be a problem if you wanted to do parametric studies or optimisation, that is my case exactly.

I do not necessairly need super accurate results but would like to roughly investigate how glazing ratio, dimensions, placement and pane types would affect lightning energy use. So i was wondering if there is another way. **Is it possible to somehow bypass daysim and do such thing using energy plus?**

Thank you for your time and help

# Energy plus lightning energy calculation

**Wujo**#1

I will suggest to keep the workflow as in the example, but choosing ONLY one or two sensors to do the daysim calculation. At the end E+ receives just a few of them as input (can’t recall the newest version of it, but in previous ones only 2 sensors were allowed).

-A.

**Wujo**#3

Abraham,

Thank you for your response. Using one sensor is perfectly fine for me but it still takes about a minute to calculate a simple geometry given in mentioned example. Considering bigger designs with a lot of iterations these can take days. I was just wondering if it was possible to make a simpler operations (ex. using sun vectors only) and to “fine tune” picked options in later design phase using more advanced tools like daysim simulations. Unfortunately I don’t code and “manual” algorithm of that kind would probably take even longer for grasshopper to calculate (considering number of vectors). A faster solution would be great for optimisation workflows (as cooling, heating loads are only a part of equation). On the other hand I understand it is not that simple + calculations need time + i get more accurate result that way. So I guess I’ll stick to that.

Once again, thank you for your advice, have a great week!

Daylight illuminance set point / Set EP zone thresholds component results

@wujo,

If you are only interested in the energy consumption of lighting you don’t necessarily need E+. The Daysim calculations can do that for you in addition that you can check different scenarios of light control types.

Anyways, simulations take time.

-A.