ask.openLCA - Question and Answer (Q&A) on Life Cycle Assessment (LCA) - A Life Cycle Assessment (LCA) Community - Recent questions and answers

Answered: Is student application for ecoinvent Educational License permitted?

Fri, 08 May 2026 10:23:22 +0000

Yes sure, this is possible.

Answered: What if Exchanges had UUIDs?

Thu, 07 May 2026 14:15:12 +0000

Within openLCA, the internalId of an exchange is not mutable. The requirement is that it is unique within a process. The process contains a field, lastInternalId, which tracks this value; it is always incremented so that an exchange never receives the same internalId twice. The pair (process.id, exchange.internalId) is unique (and is used in product system links).

An exchange is not a standalone entity in openLCA; it always exists within a process. That process provides the context (such as location, industry sector, etc.) that could be used for this "edge-based impact assessment" (very interesting, thank you for sharing the link). In fact, this is already done with the regionalization feature in openLCA: if not defined for the exchange, openLCA uses the location of the process and matches it with regionalized characterization factors.

And yes, there is more to explore (such as handling sector-specific CFs). However, I do not currently see how UUIDs for exchanges would help here.

Answered: GeoJson files for regionalized impact assessment

Thu, 07 May 2026 13:46:39 +0000

Dear Chiara,

GeoJson files are not required to perform the regionalized assessment. For that is enought that you click on "regionalized calculation" when you calculate results (of course using regionalized methods). EF 3.1 and TRACI 2.2 natively don't provide shapefiles for now.

Best,

Sarah

Is LC-Impact method in openLCA compatible with Ecoinvent 3.12?

Thu, 07 May 2026 09:31:53 +0000

Answered: methane and nitrogen gas are not available as product flows in ecoinvent, is there an alternative to them ?

Thu, 07 May 2026 07:50:36 +0000

Hi,

the nitrogen product flow is nitrogen, liquid and the methane one is either biomethane, low pressure or high pressure and/ or natural gas, high pressure (or others). You have to look into the description of the flows to understand or you look in processes where methane should be used and adopt from there (e.g. chloroform production)

Answered: do results change if i calculate the impact for a product system of processes combined vs each process on its own

Wed, 06 May 2026 18:58:22 +0000

Hi, the question is not really clear to me, but the answer is no.

Answered: Product system loops in contribution tree

Wed, 06 May 2026 10:58:25 +0000

The contribution tree turns the looped LCA system into branches of a tree that are not looped; as a consequence, processes in a loop can appear several times, every time they are "vistited" when following the links in the model graph. This is as expected.

Answered: System dynamics in OpenLCA

Wed, 06 May 2026 10:55:43 +0000

Yes, we have implemented the xmile standard, but tested with Stella (and with our models created in Stella in various projects). It is in 262 also possible to make your own model in openLCA, so you do not need a classic system dynamics software any more (!). openLCA 262 is available as a snapshot, from the development folder, in the openLCA download page:

EF v3.1 as LCIA for ecoinvent consequential as database - any implications?

Wed, 06 May 2026 07:20:28 +0000

Hi!

I'm in the midst of my thesis, where I'm conducting a consequential LCA using ecoinvent consequential data (3.12), and I was planning on using EF v3.1 as assessment method.

Have any of you come across implications using EF v3.1 for consequential LCAs, if so what kind?

Answered: Injection moulding - handle production waste

Tue, 05 May 2026 10:56:38 +0000

As Jonas wrote, it is a service process, so you add the service with the same amount as your input products for the plastics (for example 2.0 kg of a certain type of plastics and 2.0 kg of the injection moulding service).

What most do not know and what you can only see with unit processes:

Services in ecoinvent already contain the losses from production / the residuals / the waste left overs. You can see in the example above that the service has 0.006 kg (rounded here) of waste plastic mixtures in the output. This is the "surplus" that is also in the input of the service process with 0.0036 kg polypropylene, granulate and 0.0017 kg polyethylene, low density, granulate and masses from fillers. So the services will already "take care" of losses and surplus material, so that modeling is easier and only the material+service has to be added both with the same amounts and with the amounts that are actually transformed / output of the service. Feel free to add additional losses to your processes if needed.

In other services it is more obvious that the surplus/waste is already included. For example in "metal working, average for copper product manufacturing" you will find in the service 227g of copper (22.7%) coming in and 227g getting out as a recyclable, to model the surplus/waste in the service.

Answered: What databases (preferably free ones) contain citric acid datasets (food grade) ?

Mon, 04 May 2026 07:19:46 +0000

Hi,

for this, you can use the Nexus search: https://nexus.openlca.org/search/query=citric%20acid. It looks like there is a limited option on free citric acid datasets.

Should a system be established with the downstream process as the reference?

Thu, 30 Apr 2026 05:52:25 +0000

If one wants to calculate the upstream and downstream parts of the process, should a system be established based on the downstream process as the reference? For example, in the picture, "Iron phosphate, product" and "lithium carbonate, product"

Answered: How to aggregate processes to reflect the impacts of different stages ?

Wed, 29 Apr 2026 22:03:21 +0000

Hi,

maybe the introduction of analysis groups since v2.4 can help: https://greendelta.github.io/openLCA2-manual/res_analysis/res_analysis_groups.html

Answered: Merging two databases in OpenLCA

Tue, 28 Apr 2026 12:34:10 +0000

Hi, you mean this database, right : https://nexus.openlca.org/database/OzLCI2019 ?

You have done the right thing by importing the database into ecoinvent. This will add the number of background datasets available for your foreground model. This means, if you make your own process, you can add the Australian background dataset. The OzLCI2019 works with openLCA method package.

Answered: EN 15804 add on - EN15804+A2 (EF v3.1) impact method

Tue, 28 Apr 2026 09:06:56 +0000

You will need it if you do an EPD for EPD Norge (now EPD Global) or EPD International. But in this case, you will also see the description of this indicator in the PCRs of the programme operators that you need for the modeling and result reporting rules. This indicator has the abbreviation GWP-IOBC/GHG.

We also have a description in the impact category description field (maybe not in the older versions), where we write:

Method: EF v3.1 EN15804 implementation from ecoinvent database v3.12, GWP-total but the biogenic carbon dioxide uptake ("Carbon dioxide, in air"), the biogenic carbon dioxide emissions ("Carbon dioxide, non-fossil") and the biogenic carbon dioxide correction ("Carbon dioxide, non-fossil, resource correction") is set to zero.

Impact category UUID: Taken from EPD International / ECO-Platform

This impact category is not part of the official EN15804 reference package, but is used in EPDs and sometimes called GWP-GHG (EPD International) or GWP-IOBC (EPD Norge / EPD Global). Because only one UUID number exists in the ILCD+EPD v1.2 MR6 format reported by the indata network (https://www.indata.network/resources) the UUID number for EN15804 EF 3.0 is taken from the ILCD+EPD v1.2 MR6 format and the UUID number for EN15804 EF 3.1 is taken from EPD International.

How should evaporated water be modelled in openlca?

Tue, 28 Apr 2026 08:04:23 +0000

Hi,

I am using openLCA with the BAFU 2025 database and EF 3.1 adapted. I need to model water separated from drilling sediments that is pumped to a basin and passively evaporates.

I used “Water vapour” as an elementary output to air, but it has no characterization factor in EF 3.1 adapted, so the water use impact is zero.

What is the correct flow to use for evaporated water in BAFU 2025? Should this evaporation be characterized in EF 3.1 water use, or should I keep “Water vapour” only as an LCI flow and report the evaporated amount separately?

Answered: Import database in Gabi to openLCA

Mon, 27 Apr 2026 14:36:46 +0000

No, you will need to register this license in Nexus, for a fee (lower than the initial license fee), and will then receive the database prepared for openLCA from Nexus.

Best wishes,

Andreas

Answered: Ecoinvent 3.12 -Difference between Cutoff System and Cutoff Unit

Mon, 27 Apr 2026 14:34:18 +0000

unit has unit processes, system has system processes.

Answered: openLCA on MacOS future big big problem

Sun, 26 Apr 2026 15:03:56 +0000

We know of it already and our IT works on a native ARM version for Apple Silicon Macs.

The change from Apple to stop supporting x64 apps via Rosetta will happen earliest in September with the new MacOS 27.

Answered: How to export list of "Total requirements" from direct calculation?

Fri, 24 Apr 2026 13:57:33 +0000

well, copy and paste?

Answered: Regionalized Calculation active causes negative values [ecoinvent in OPENLCA]

Fri, 24 Apr 2026 08:36:04 +0000

Hi,

the ecoinvent database itself has no regionalized characterisation factors. So, using the option is not helpful. Please have a look at the regionalisation chapter: https://greendelta.github.io/openLCA2-manual/advanced_top/regionalized.html.
Hope this helps

Handling large farm-level datasets (~9000 fields) in openLCA

Thu, 23 Apr 2026 17:07:54 +0000

Hello,

I am working on an LCA study of maize production systems (rainfed vs irrigated) using openLCA, and I have a dataset of approximately 9,000 individual fields (farms), each with different input data (fertilization, yield, energy use, irrigation, etc.).

I would like to ask for advice on the best approach to handle this type of large dataset in openLCA:

Is it feasible (or recommended) to create and calculate thousands of individual processes within openLCA?
Would using the openLCA IPC interface for automation be a suitable approach for this scale?
Alternatively, is it better practice to use openLCA to obtain background data (e.g., emission factors) and perform the large-scale calculations externally (e.g., Python or R)?

My goal is to ensure a robust and efficient workflow suitable for scientific publication.

Any recommendations or examples of similar use cases would be greatly appreciated.

Thank you very much!

Answered: OpenLCA crashes when hovering "Description"

Tue, 21 Apr 2026 08:57:12 +0000

Same here. Freeze when hovering over the description of the output "biowaste"

Answered: Monte Carlo simulation not generating any results

Mon, 20 Apr 2026 21:45:44 +0000

Maybe to find out the reason, some more questions: Which database type did you use, unit process, system process or library? Have you entered the uncertainties in exchanges of product flows that have a supply chain with impacts connected? Which uncertainty type did you chose, always log-normal for example? When you click on one of the exchange uncertainties and you run „test“, do you see the uncertainty statistics for 100 runs?

Answered: How to avoid multiplying upstream process impacts when outputs go to different downstream processes?

Mon, 20 Apr 2026 11:50:03 +0000

In the result calculation, the process is contributing to each of the supply chain branches where it is used with the specific amount required in each branch. If you check the impact analysis, you will see the process only once, with all impacts combined. The contribution tree intentionally splits the entire system into different branches, so that you can see the impact of different branches of your life cycle on the result. You do not need to follow specific modeling tricks or so to make openLCA calculate this correctly.

Sometimes, in systems with many loops, the "linearisation" into branches that is done for the contribution tree is difficult and openLCA then uses an approximation. The entire result, as shown in the impact analysis, is not affected by this.

Hth, Andreas

Answered: How to easily visualize the environmental impacts of only the processes entered by the user

Fri, 17 Apr 2026 08:33:27 +0000

I think you would only be able to achieve this with some workarounds - at the moment at least. One option would be to go through the impact categories using the Contribution Tree, extending it to show the processes in question. The other option is to save the respective processes as system processes, then calculate the results and export. But both options would take some time.

Impact assessment methods for Exiobase 3.4 + mapping files

Thu, 16 Apr 2026 07:37:03 +0000

Hi All,

when appying the EXIOBASE Input factors assessment method to an EXIOBASE 3.4 product system built out of a standard process ("Construction work (45) - IT") I am getting a result for the "Value added" indicator but not for the "Employment" and "Employment hours" indicators. Is that right?

Also, is there any mapping file available that can help bridging at least some of the indicators included in the ReciPe 2016 v1.03 method? We are currently working on an extremely interesting impact valuation modeling project which is using data from ReciPe to model spend-based activities not covered in Ecoinvent.

Thanks,

Andrea

Answered: Process amounts randomly invisible in v 2.6.0

Wed, 15 Apr 2026 14:31:35 +0000

Strange, but Mac has sometimes some UI glitches, depending on the OS version; I am not aware this was reported before. Can you maybe provide more details? Does it persists with 2.6.1 as well?

Thank you!

(you did not attach an image)

Answered: How can I download Agribalyse data for use in OpenLCA?

Wed, 15 Apr 2026 11:49:11 +0000

You need to register the license first in Nexus (or, buy it from Nexus next time, for the same price as from ecoinvent).

How can I model in openLCA industrial symbiosis of wooden pallet?

Tue, 14 Apr 2026 12:39:02 +0000

I have to model a scenario in which Industrial Symbiosis of pallet is assessed. Is it possible to make a model where i start from the raw material supply for the pallet manufacturing, then i consider the distribution and use, and then, instead of the EoL, I consider the industrial symbiosis stage, where the disposable pallet is used fro the prodcution of a wooden piece of furniture?

Answered: Combining parts of EXIOBASE into ecoinvent

Mon, 13 Apr 2026 10:53:24 +0000

Hi and welcome,

8GB is really not much, but if you use the libraries of both databases, that should work.

Best wishes,

Andreas

edit on response to your comment:

I meant this (also available in the DAL I think):

Check here about libraries in openLCA: https://greendelta.github.io/openLCA2-manual/libraries/index.html (and related pages)

Answered: Log file - Error when updating maximum memory usage in 2.6

Thu, 09 Apr 2026 18:27:32 +0000

I guess you have no user rights to write files in the openLCA folder. Try it with the admin account, or use the zip-version of openLCA that you can simply unzip in a folder of your choice (which will have for sure access rights when you can open it or create it).

Is it possible to show unit processes as single contributors like system processes in openLCA?

Wed, 08 Apr 2026 16:02:15 +0000

Hi everyone,

I am working with ecoinvent 3.11 (cut-off) in openLCA and I modified some unit processes, for example a landfill process (treatment of inert waste) and a diesel combustion process, to better reflect my specific case (PFAS-related waste).

For modelling reasons, I need to use unit processes (to adjust emissions), but for interpretation I would like to see the results in a more aggregated way.

The problem is:
When I run the LCIA, the contributions of my modified processes are fully disaggregated into upstream processes (electricity, transport, materials, etc.).
So I no longer get a clear result like:

“X kg CO₂-eq – treatment of inert waste”

but instead many small contributions from background processes.

With system processes, this aggregation works fine (e.g. “market for electricity” appears as one contributor), but then I cannot directly modify the emissions.

So my question is:

Is there a way in openLCA to display or aggregate results of unit processes so that they appear as a single contribution (similar to system processes)?

For example:

grouping all upstream contributions under the foreground unit process
or forcing contribution analysis at the level of selected processes

If not directly possible:

what would be the recommended workaround?

Answered: SOCA: How is the activity value (social assessment) calculated and how does it differ from the activity variable?

Wed, 08 Apr 2026 13:07:52 +0000

Hello Katrin
Activity variable is the same as acitivity value you see in social assessment tab per process. However, yes the single acitivity value you see per social indicator is weigthed average acitivity variable.

Answered: SOCA: How would you proceed, to do a social hotspot analysis?

Wed, 08 Apr 2026 13:05:25 +0000

Hello Kathi
Both impact assessment and social assessment tabs are important to look at. I am assuming you are looking at soca v4 so impact assessment shows all the impact categories which represent each social indicator in medium risk hours. Social assessment give you further details on how each social indicator per process along the supply chain is being evaluate at what risk level.
I recommend chapter 2.7.2 in PSILCA manual to learn more openLCA Nexus: The source for LCA data sets

Kind regards.

Ash

Answered: Download links from openLCA homepage and nav bar are broken. The fix:

Mon, 06 Apr 2026 13:48:02 +0000

eh - no (at least not for me)? But thank you for reporting

edit: we tested and it depends on the browser, most automatically convert the old http link to https, some don't - and thus we updated the links now on the site. Thank you again for reporting it.

Excel Import: Importing same product flows with providers from various locations

Wed, 01 Apr 2026 15:52:02 +0000

I'd like to import processes that have input and output flows from providers that only differ in terms of their location.

Here is an example to make it feasible - I'd like openLCA to recognise the following via excel import:

Inputs:

Flow	Provider
electricity, low voltage	market for electricity, low voltage \| electricity, low voltage \| Cutoff, U - EC
electricity, low voltage	market for electricity, low voltage \| electricity, low voltage \| Cutoff, U - BE
(...)	(...)

Outputs:

Flow	Provider
heat, district or industrial, natural gas	market group for heat, district or industrial, natural gas \| heat, district or industrial, natural gas \| Cutoff, U - RER
heat, district or industrial, natural gas	market group for heat, district or industrial, natural gas \| heat, district or industrial, natural gas \| Cutoff, U - GLO
(...)	(...)

(In this case, heat energy is avoided)

In the excel file, this is reflected in the following entries in the "Providers" tab:

Though, when importing the excel file only the first providers are recognised by openLCA, leading to the both input providers being "EC", and both output providers being "RER". In general, it is not clear to me how openLCA links the entries made in the "Inputs" and "Outputs" tabs to the providers in the "Providers" tab.

My questions:

1) Is there something like a general guidance document for preparing excel files for process import? In the openLCA manual, I only found very few information.

2) Is it, at all, possible to import multiple located providers using the excel template, and if so, how?

3) The answer to 2) is "no", what would be the easiest and fasted alternative? I currently have all my data ready in an excel copy-paste format, as well (copy-pasting inputs and outputs is fully working, but the goal is to automate the process for hundreds of process datasets).

Thank you in advance to anyone who can help out - also, don't hesitate to ask any questions in case you need more information.

Best regards,

Johannes

Answered: Wrong NH₃/NOx CFs in ReCiPe 2016 Midpoint (H) Terrestrial acidification – openLCA LCIA Methods 2.8.0?

Wed, 01 Apr 2026 10:07:46 +0000

Hi,

Thank you for your detailed feedback. This looks indeed like an implementation error. We’ll address it in the next update release of the method package.

We appreciate you bringing this to our attention.

Best regards,

Sarah

How to do LCSA with social, ecological and economic sustainability?

Tue, 31 Mar 2026 16:13:14 +0000

Holistic and Integrated Life Cycle Sustainability Assessment (HILCSA). It was developed by Helmholtz Centre for Environmental Research (UFZ) to enable a comprehensive and integrated assessment of social, ecological, and economic sustainability. Using around 80 indicators linked to the UN Sustainable Development Goals, it helps identify trade-offs, synergies, and hotspots across sustainability dimensions. HILCSA has already been used for various case studies. https://nexus.openlca.org/database/HILCSA

Answered: Can I export all LCIA results from the "contribution tree" tab for all impact categories in one step?

Mon, 30 Mar 2026 17:34:32 +0000

Hi everyone.

I'd like to revisit this crucial question (especially for design offices specializing in eco-design that want to migrate from Sima Pro to OpenLCA): how can I easily export a matrix with:

- in rows: the calculated impacts (e.g., climate change, eutrophication, etc.)

- in columns: the processes entered and used in the modeling (e.g., xx kW of electricity, xx km of transport, xx kg of PVC, etc.)?

Visualizing this matrix is essential because it allows for the rapid identification of the most impactful processes for each impact category.

What is the fastest way to obtain this visualization?

Many thanks for your feedback.

Answered: Error in making a product system.

Mon, 30 Mar 2026 10:08:39 +0000

Hi, this is really strange - maybe the installation was incomplete. Can you retry to install, from a fresh download?

Answered: Where is the download for the Circularity Package?

Mon, 30 Mar 2026 09:49:37 +0000

Hi, it is here:

Best wishes,

Andreas

Answered: EPD results parametrization

Thu, 26 Mar 2026 12:03:01 +0000

Hello Jocelyn,

can you maybe explain more how do you wish for it to be parametrized ? like in the element of "results" itself at the impact categories table ?

Answered: How can I get ecoinvent database for free on openLCA?

Thu, 26 Mar 2026 11:46:39 +0000

You are probably eligible for the free educational ecoinvent database license for lower income countries, please check the license text on Nexus.

PC and PET Bottles case study, 9: End-of-life modelling, Problem getting the required processes into the database

Mon, 23 Mar 2026 14:02:55 +0000

Hello!

I am trying to learn how to use the OpenLCA software with the “Modelling PC and PET Bottles” case study. In section 9: End-of-life modelling, there is a link through which the processes “Waste incineration of plastics (Material Flow Logic)” and “Waste incineration of plastics (Opposite Direction Approach)” should be imported into the database. However, the link does not work.

How should I proceed so that I can complete the case study?

Answered: How to get impact result of each individual flow per impact category in openLCA IPC Python?

Mon, 23 Mar 2026 10:00:08 +0000

Hi,

It seems you can access it after a calculation via: "Result.get_direct_impact_values_of". You'll have to make your own script using this function. See here: https://greendelta.github.io/openLCA-ApiDoc/results/impacts/direct-contributions.html

I'll let Greendelta precise or correct my answser :-).

Nicolas

Answered: How to get output flow battery pack quantity in "item"

Fri, 20 Mar 2026 11:13:23 +0000

Ah true, the unit is called "item(s)", the flow property is number:

Answered: followed Basic exercise but couldn't get battery pack impact analysis

Thu, 19 Mar 2026 10:02:52 +0000

The direct contributions are only the direct contributions of one process (battery pack), while the analysis that you have above is for an entire life cycle model (which you conveniently also called battery pack), and only these are nested and can thus be "unfold".

Hth, Andreas

Answered: Processes gone and can't find: All of the processes I created are gone

Wed, 18 Mar 2026 09:15:28 +0000

Hi, well difficult to say, you can check whether there are indeed no processes left

(e.g.: select * from tbl_processes, as sql).

You do not have a backup of your database?

Answered: Are trainings offered in either PST or EST so they can be attended by folks in the United States?

Tue, 17 Mar 2026 17:59:31 +0000

Hi, sure - we typically have trainings with CET afternoon sessions for half a day with US participants, and then also morning sessions for attendees from Asia and Australia - ideally check this before booking a training, thank you.