Results between OpenLCA and OLCA-IPC differ - sometimes

Question

Hey :)

I experience the same issue like in Results between OpenLCA and OLCA-IPC differ. 

I am using the ecoinvent 3.9.1 consequential upr data, OpenLCA 2.0.4 and olca 2.0.2 . 

I experience this issue with the original market electricity processes. I create product systems within openlca and use the specific id to calculate with olca. For all electricity processes I have tested so far, I get different results in OpenLCA ('calculate') and olca. I double checked the impact method. I have the feeling, that olca does not recognize or include all provider contributions.

I created the procut system from this process: 'ebd1677d-a57c-3309-aefe-be1cd88f68a1' with the following setting: Linking approach during creation: Prefer default providers; Preferred process type: System process

Here is the code:

import olca_ipc as ipc
import olca_schema as o
import pandas as pd
def lcaproductsystem(id):
impact_categories = []
product_system = [id]
# create a calculation setup
setup = o.CalculationSetup(
target=o.Ref(
ref_type=o.RefType.ProductSystem,
id=id,
),
impact_method=o.Ref('c99194f6-351f-425a-82eb-6cd9654cefca'),

)

# run a calculation
client = ipc.Client()
result: ipc.Result = client.calculate(setup)
state = result.wait_until_ready()
result.get_impact_categories()
impact_category_ref = o.Ref(
ref_type=o.RefType.ImpactCategory,
id='6446ccbd-fd85-4332-95aa-d6107b3ceef6' # ID of the impact category
)
results = result.get_total_impacts()
contributions = result.get_impact_contributions_of(impact_category_ref)

impact_categories = [(str(n.impact_category.name)) + ' ' + str(n.impact_category.ref_unit) for n in results]
df = pd.DataFrame(columns=product_system, index=impact_categories)
df[str(product_system)] = [n.amount for n in results]
result.dispose()
return df, contributions

x = lcaproductsystem(id = '623ac099-df08-4abe-b534-769710b7ea77')

Answer 1

I could find your process, impact method, impact category. Since you said that all electricity processes are affected: have you checked the units? My guess is that you calculated inside the openLCA software the results for 1 kWh and with the OLCA-IPC for 1 MJ (reference unit for "Energy").

Result for 1 kWh:

0.53065 kg CO2-Eq

Results for 1 MJ:

0.14740 kg CO2-Eq

Comments

For the OLCA-IPC I don't know it spontaneously. I guess that the OLCA-IPC is always calculating the reference unit as a default, so that users do not mix up different units.

But inside the openLCA software you can select for your product system MJ instead of kWh, or you can also select kWh as the reference unit for the whole database inside the unit group for "Units of energy". Or you can simply convert MJ and kWh results whenever you want with a factor of 3.6 MJ = 1 kWh.