How do I use my own weather files?

[AugustVan]

What do I have to change in this piece of code to be able to use my own epw weather files?

[shirubana]

in theory noting, if your EPW is in the right format for EPWs. IF it is giving an error that means some of the columns or formating is not the standard, check the documentation for EPW on the EnergyPlus webiste.

The function expects an EPW with extension EPW.

if you want to specify other formats, we currently support on hte main branch:
source : str
To help identify different types of .csv files. If None, it assumes
it is a TMY3-style formated data. Current options: 'TMY3',
'solargis', 'EPW'

And the development branch has 'sam' (psm3 format) and NSRDB data input as well.

S.

[AugustVan]

I don't think i'm using the wrong file because it's an epw file, I just think it's my lack of programming skills. Would it be possible to show the lines of code it takes to use my own epw files?

[shirubana]

sure, you can either share it here, or to my email silvana.ovaitt@nrel.gov, or we can have a short meeting to iron it out (couple 30 mins spot open today and tomorrow but more on wednesday)

[AugustVan]

This is the code I have at the moment.

import os
from pathlib import Path
from bifacial_radiance import *
import numpy as np
import pandas as pd

testfolder = str(Path().resolve().parent.parent / 'bifacial_radiance' / 'TEMP' / 'August')
if not os.path.exists(testfolder):
os.makedirs(testfolder)

testopstelling = RadianceObj('x',str(testfolder))

testopstelling.setGround()
albedo = 0.7
testopstelling.setGround(albedo)

#GETTING WHEATER FILE
epwfile = testopstelling.getEPW(lat = 37.5, lon = -77.6)
metdata = testopstelling.readWeatherFile(epwfile, coerce_year=2001)
fullYear = True
if fullYear:
testopstelling.genCumSky() # entire year.
else:
timeindex = metdata.datetime.index(pd.to_datetime('2001-06-17 12:0:0 -7'))
testopstelling.gendaylit(timeindex) # Noon, June 17th (timepoint # 4020)

#CREATING A MODULE
moduletype = 'test-module'

num_panels = 1
x = 0
y = 0
x_gap = 0.20
y_gap = 0.10
z_gap = 0

num_cells_x = 12
num_cells_y = 24
x_cell = 0.17283
y_cell = 0.08692
x_cell_gap = 0.002
y_cell_gap = 0.002

cellLevelModuleParams = {'numcellsx': num_cells_y, 'numcellsy': num_cells_x,
'xcell': y_cell, 'ycell': x_cell, 'xcellgap': y_cell_gap, 'ycellgap': x_cell_gap}

module = testopstelling.makeModule(name=moduletype, x=x, y=y, numpanels=num_panels,
xgap=x_gap, ygap=y_gap, cellModule=cellLevelModuleParams)

#Making the scene
pitch = 9 # m
albedo = 0.22 # 'grass' # ground albedo
hub_height = 1.9 # m
nMods = 6 # six modules per row.
nRows = 3 # 3 row
azimuth_ang = 270 # Facing west
tilt = 90 # tilt.

sceneDict = {'tilt': tilt, 'pitch': pitch, 'hub_height': hub_height, 'azimuth': azimuth_ang, 'nMods': nMods,
'nRows': nRows}

scene = testopstelling.makeScene(module=moduletype, sceneDict=sceneDict)

#CREATING FRAME
torquetubelength = 14.036
postheight = 0.05
postwidth = 0.03

post_x = -2.285
z_step = 1.148
y_step = 9

y = 9.127

for i in range(3):
post_z = 2.9
for j in range(3):
name = 'Post{}{}'.format(i, j)
text = '! genbox Metal_Aluminum_Anodized torquetube_row2 {} {} {} | xform -t {} -0.2 0.15 | xform -t {} {} {} '
'| '
'xform -rz 90'.format(
torquetubelength, postheight, postwidth, (-torquetubelength + module.sceney) / 2.0, post_x, y, post_z)
customObject = testopstelling.makeCustomObject(name, text)
testopstelling.appendtoScene(radfile=scene.radfiles, customObject=customObject, text="!xform -rz 0")
post_z -= z_step

y -= y_step

pileheight = 3.05
pilewidth = 0.05
piledepth = 0.05

x_offset = - 0.1
y_step = 2.15

x_value = -9
for i in range(3):
y_value = -8.23
for j in range(7):
name_string = 'pile{}{}'.format(i, j)
text = ('! genbox Metal_Grey pile{}row{} '.format(i, j) + '{} {} {} '.format(pilewidth, piledepth, pileheight)
+ '| xform -t {} {} {}'.format(x_value, y_value, 0))
customObject = testopstelling.makeCustomObject(name_string, text)
testopstelling.appendtoScene(scene.radfiles, customObject, '!xform -rz 0')
y_value += 2.331

x_value += 9

testopstelling.scene.showScene()
#ANALYSIS
octfile = testopstelling.makeOct(testopstelling.getfilelist())

analysis = AnalysisObj(octfile, testopstelling.basename)

frontscan, backscan = analysis.moduleAnalysis(scene)

results = analysis.analysis(octfile, testopstelling.basename, frontscan, backscan)

load.read1Result('results\irr_x.csv')

bifacialityfactor = 0.9
print('Annual bifacial ratio: %0.2f ' %( np.mean(analysis.Wm2Back) * bifacialityfactor / np.mean(analysis.Wm2Front)) )

scene.saveImage()
analysis.makeImage('side.vp')
analysis.makeFalseColor('side.vp')

[shirubana]

Hi AugustVan

So, if you have an epw file you have to pass the file name/direction here:

epwfile= r'C:/Users/AugustVan/Documents/LocationEPWfile.epw
metdata = testopstelling.readWeatherFile(epwfile)

Let me know if this doesnt work

[AugustVan]

Hh I forgot the r' ', thanks alot!

[shirubana]

yeah python has weird things like that. lmk other questions through here or email

S.