Pvwattsv8 solar_resouce_data not working

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isaiahgarcia
Topic Author

20 Jun 2024 02:08 #13269 by isaiahgarcia

Pvwattsv8 solar_resouce_data not working was created by isaiahgarcia

Hello! I am currently using PySAM.PSSC and PySAM.Pvwattsv8 and I am running into issues when using solar_resource_data instead of solar_resource_file.

Essentially, I have a weather dataset as a Pandas.dataframe created from this NREL API (developer.nrel.gov/api/nsrdb/v2/solar/psm3-2-2-download.csv). Instead of converting that dataframe to csv in my local storage and declaring the solar_resource_file field, I just want to populate solar_resource_data with my weather data.

Here is the specific code block I am using:

import PySAM.PySSC as pssc
import PySAM.Pvwattsv8 as pv8
from datetime import datetime, timedelta
start_time = datetime(2022, 1, 1)
time_delta = timedelta(hours=1)
num_hours = 8760
solar_resource_data = {
"lat": info["Latitude"][0],
"lon": info["Longitude"][0],
"tz": info["Time Zone"][0],
"elev": info["Elevation"][0],
"year": [],
"month": [],
"day": [],
"hour": [],
"minute": [30] * num_hours,
# "dn": list(site_generation["DNI"]),
# "df": list(site_generation["DHI"]),
# "gh": list(site_generation["GHI"]),
# "wspd": list(site_generation["Wind Speed"]),
# "tdry": list(site_generation["Temperature"])
"dn": [500]*num_hours, # Example values, replace with actual data
"df": [100]*num_hours, # Example values, replace with actual data
"gh": [600]*num_hours, # Example values, replace with actual data
"wspd": [3]*num_hours, # Example values, replace with actual data
"tdry": [20]*num_hours # Example values, replace with actual data
}
for hour in range(num_hours):
current_time = start_time + time_delta * hour
solar_resource_data["year"].append(current_time.year)
solar_resource_data["month"].append(current_time.month)
solar_resource_data["day"].append(current_time.day)
solar_resource_data["hour"].append(current_time.hour)
pv_model = pv8.new()
pv_dat = pssc.dict_to_ssc_table(pvwatts_json, "pvwattsv8")
pv_model = pv8.wrap(pv_dat)
pv_model.SolarResource.assign({"solar_resource_data": solar_resource_data})
pv_model.execute()
pv_model.Outputs.dc

When I print out the dc/ac electricity values, I am seeing a list of all 0.0. I tried out the same exact code block replacing solar_resource_data with the solar_resource_file I create, and that works correctly because I am seeing expected outputs.

My main question is if the solar_resource_data is no longer a viable use case for this version of Pvwattsv8?

...ttsv8_code.png

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pgilman

20 Jun 2024 18:01 #13270 by pgilman

Replied by pgilman on topic Pvwattsv8 solar_resouce_data not working

Hi Isaiah,

The 'solar_resource_data' variable is an input to the Pvwattsv8 module:

nrel-pysam.readthedocs.io/en/main/modules/Pvwattsv8.html#PySAM.Pvwattsv8.Pvwattsv8.SolarResource.solar_resource_data

Please make sure that your 'pvwatts_json' file does not assign a value to 'solar_resource_file'. The model determines whether to use the weather file or the dictionary based on which variable is assigned: It first checks to see if 'solar_resource_file' is assigned and uses it if assigned, then checks 'solar_resource_data' to see if it is assigned. This means that if the JSON assigns a value to 'solar_resource_file', it will ignore the 'solar_resource_data' variable.

The source code for this behavior is here:

github.com/NREL/ssc/blob/9cadfe3d36a74614a2550065f37388bc8aa2aecf/shared/lib_pv_io_manager.cpp#L125

Best regards,
Paul.

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isaiahgarcia
Topic Author

20 Jun 2024 19:08 - 09 Jul 2024 17:31 #13272 by isaiahgarcia

Replied by isaiahgarcia on topic Pvwattsv8 solar_resouce_data not working

Hi Paul,

Thank you for replying! I can confirm that I do not have a 'solar_resource_file' value defined in my pvwatts_json file. I can confirm this by printing out 'PySAM.Pvwattsv8.Pvwattsv8.SolarResource.solar_resource_file' and it gives me an error because it is not assigned (which is what I want).

I can also confirm that my 'solar_resource_data' is properly assigned after I run this line:

Pvwattsv8.SolarResource.assign({'solar_resource_data': solar_resource_data_var})

My guess at this point is the dictionary is not in the correct format/structure. I attached a link of my example 'solar_resouce_data' dictionary.

example.json

Last edit: 09 Jul 2024 17:31 by pgilman. Reason: Format code section

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pgilman

24 Jun 2024 15:13 #13274 by pgilman

Replied by pgilman on topic Pvwattsv8 solar_resouce_data not working

Hi Isaiah,

Here is some code that I think does what you want:

import PySAM.Pvwattsv8 as pv8
import json

from datetime import datetime, timedelta

start_time = datetime(2022, 1, 1)
time_delta = timedelta(hours=1)
num_hours = 8760

solar_resource_data = {
    "lat": 0,
    "lon": 0,
    "tz": 0,
    "elev": 0,
    "year": ,
    "month": ,
    "day": ,
    "hour": ,
    "minute": [30] * num_hours,
    # "dn": list(site_generation["DNI"]),
    # "df": list(site_generation["DHI"]),
    # "gh": list(site_generation["GHI"]),
    # "wspd": list(site_generation["Wind Speed"]),
    # "tdry": list(site_generation["Temperature"])
    "dn": [500]*num_hours, # Example values, replace with actual data
    "df": [100]*num_hours, # Example values, replace with actual data
    "gh": [600]*num_hours, # Example values, replace with actual data
    "wspd": [3]*num_hours, # Example values, replace with actual data
    "tdry": [20]*num_hours # Example values, replace with actual data
}

for hour in range(num_hours):
    current_time = start_time + time_delta * hour
    solar_resource_data["year"].append(current_time.year)
    solar_resource_data["month"].append(current_time.month)
    solar_resource_data["day"].append(current_time.day)
    solar_resource_data["hour"].append(current_time.hour)

pv_model = pv8.default("PVWattsNone") # see https://nrel-pysam.readthedocs.io/en/main/sam-configurations.html

print("== Test with no weather data ==")

# model will fail because defaults do not include weather
verbose_simulation = 1
try:
    pv_model.execute(verbose_simluation)
except:
    print("\npv_model failed")

print("\n== Test with constructed data ==");

# assign resource data constructed above
pv_model.SolarResource.assign({"solar_resource_data": solar_resource_data})

print("\nDNI from inputs:")
print(pv_model.SolarResource.solar_resource_data["dn"][0:23])

pv_model.execute()

print("\nDC output:")
print(pv_model.Outputs.dc[0:23])

print("\nDNI from outputs:")
print(pv_model.Outputs.dn[0:23])

print("\n== Test with data from JSON ==");

with open( 'example.json', 'r') as f:
        pv_inputs = json.load( f )

print("\nDNI from inputs:")
print(pv_model.SolarResource.solar_resource_data["dn"][0:23])

pv_model.execute()

print("\nDC output:")
print(pv_model.Outputs.dc[0:23])

print("\nDNI from outputs:")
print(pv_model.Outputs.dn[0:23])

Best regards,
Paul.

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