December 2025

New features

• The modelling of solar PV has been improved:
  • New sliders to set the full load hours separately for solar rooftop (households), solar rooftop (buildings), solar on land and solar offshore.
  • Updated default hourly profiles of solar PV technologies for the European datasets in the ETM, based on the Pan European Climate Database (PECD). Go to the Dataset Manager to find this data for a specific dataset.
  • The default hourly profiles can be overwritten by uploading custom profiles in the Flexibility section of the model.
• The scenario landing page has been changed from a generic introduction to working with the ETM to a scenario dashboard.
• The output products of a selection of processes for liquid fuels production have been updated to match existing standards.
• The start year data for Northern Ireland has been revised and updated.

Bug fixes

• Unused surplus heat production in district heating networks, the industrial steam network and from local CHPs in agriculture, were previously allocated to the final energy demand of their respective sectors. This has been changed so that unused heat is no longer part of final energy demand but is considered as a loss. This may have changed final energy demand in existing scenarios.
• The data exports sometimes showed error messages when exporting curves of private scenarios. This has been fixed.
• There was a bug in sliders that set the efficiency of power plants, resulting in an overestimation of electricity production. This bug has been resolved.
• There was some faulty behaviour in scenario collaboration which has been resolved. Go to MyETM to start collaborating on scenarios.
• Various other improvements and minor bug fixes have been made.

November 2025

November 2025

Liquid fuels improvements

The modelling of liquid fuels production and consumption has been improved by adding new production processes and expanding final demand sectors.

This improvement includes various new features and changes, among others:

• A new section Liquid fuels and feedstock has been added, containing existing and new processes for liquid fuels production. Go to the documentation for more information.
• The following energy carriers have been added to the model: bionaphtha, biomethanol, pyrolysis oil and pyrolysis bio-oil.
• Final demand in the chemical industry, national and international transport has been expanded with existing and new energy carriers.
• Improvements have been made in the calculation of primary demand for biogenic carriers. This may have resulted in changes to existing scenarios.
• The existing Oil refineries and Transport fuels sections have been relocated in the model to be better fit their role in the energy system.

Other new features

• The hourly availability of the power-to-heat technologies for district heating in the Flexibility section is now temperature-dependent. Go to the documentation for more information.
• PyETM is the standard Python package used to connect to the API of the ETM. A completely renewed version is now available as a pre-release on PyPI.
• Various improvements in user experience have been made, such as automatic chart rescaling in Collections when switching units and enhanced functionality for editing scenario collections in MyETM.

Bug fixes

• The hourly profiles in the data exports for heat in the built environment started on the 1st of April. They have been corrected to start at the 1st of January.
• There was an error in the biomass potentials in the start year data of regional Dutch datasets. This error has been rectified; the datasets now contain the correct biomass potentials. Consult the Dataset Manager to view the potentials for a specific region.
• The datasets of Norway and Serbia contained incorrect values for aluminium production in the start year. These values have been updated. Consult the Dataset Manager to see the country-specific values.
• For some regional Dutch datasets, a bug has been solved in the hourly profiles. Similar to the other regional datsets, the hourly profiles are now based on the national dataset.

October 2025

New start year 2023 for the Netherlands

Replacing 2019 as the start year, 2023 is now set as the default for new scenarios for the Netherlands and all its regions: municipalities, provinces and RES regions.

This start year update also includes improvements in data quality, among others:

• Updated values for final demand and energy production across all sectors, based on recognized data sources such as Eurostat, CBS, Klimaatmonitor and Emissieregistratie.
• Enhancements in data on heat demand in the built environment, such as insulation values and useful heat demand, by using more up-to-date and higher-quality sources.
• Significant improvements in hourly supply and profiles, aligning with recognized data sources such as the Pan-European Climate Database (PECD).
• Overall improvements in data transparency and documentation, see the Dataset Manager for the regional datasets and ETDataset for the national dataset.

Note: the national dataset is added to the model, which means that all existing scenarios with start year 2019 remain unaffected. The regional datasets however are updated to 2023, which means that all existing scenarios with start year 2019 have been changed to the new start year. As a result, scenario results may have changed.

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Bug fixes

• After the addition of naphtha in the August release, the energetic CO₂ emissions of the industry sector were wrongly included non-energetic emissions for naphtha, leading to an overestimation of this sector’s CO₂ emissions. The original emissions are now restored by excluding non-energetic naphtha.
• For steel-producing European countries (excluding the Netherlands), the transformation input of cokes in blast furnaces was counted twice in the start year data. This issue has been fixed. The flows of the Eurostat energy balance, see the Dataset Manager, are now more accurately represented in the ETM.
• In some charts, the hourly electricity demand of cooling in buildings did not cover all cooling technologies. This has been fixed.

2025.09

September 2025

New features

• Several sliders in the Biomass section have been moved to more intuitive locations in the model. Specifically:
  • The use of wood pellets in cyclone ovens for steel production can now be set in the Steel section.
  • The sliders that set the oil mix per demand sector have been moved to their respective demand sectors: Industry, Agriculture, Households and Buildings. Note: for some regions it is not possible to set the oil mix for all demand sectors.

Bug fixes

• The costs and revenue of respectively imported and exported electricity were calculated incorrectly. This has now been fixed, which causes the net costs of electricity exchange with neighbouring countries to change for existing scenarios.
• The data export of annual costs was not working due to an issue. This has been fixed.
• Due to an issue in the modifiable profiles, uploading a custom profile for weather-related profiles (such as solar PV and wind) gave an error. This issue has been solved: the weather-related profiles can now be uploaded again without any errors.

2025.08

August 2025

New features

• Naphtha is now explicitly modelled in the ETM. Previously, naphtha was included in the aggregated carrier oil products as a product from refineries. Changes include:
  • Naphtha can be produced by refineries or imported in case of shortages.
  • Assumptions can be made for the final demand of naphtha in the chemical industry as an energetic fuel or as (non-energetic) feedstock.
  • Datasets are updated to include the production and final demand of naphtha in the start year. See the Dataset Manager for data for a specific region.
  • Results in existing scenarios might change slightly as a consequence of splitting off naphtha from oil products.
• Existing scenarios created for Germany and Denmark with start year 2015 are now updated to 2019. This may have affected outcomes for those scenarios.

Bug fixes

• Modifiable profiles of type 'Capacity profile' (such as solar PV and wind profiles) are now downloaded in the same format as they should be uploaded. Previously, a normalised profile was obtained when downloaded, which required a conversion step to transform the profile to the required format in which it needed to be uploaded. This is not needed anymore. Read more about modifiable profiles in the documentation.
• For a few Dutch provincial and RES datasets, a minor correction was made in the rounding values in the start year data. The fix might have resulted in very slight changes (if any) in households heat demand in existing scenarios.

2025.07

July 2025

New features

New tables available to explore economic viability

The ETM now includes three new economic viability tables that provide comprehensive cost-benefit analyses for electricity production, storage, and flexible demand technologies. The tables enable users to gain a first insight in the cost effectiveness of these assets. The tables can be found in the "Cost" section of the charts selection. See the documentation for more information.

Other new features

• With the next Deploy in August, all existing scenarios for Germany and Denmark with start year 2015 will automatically be updated to start year 2019.

Note: the outcomes for these scenarios are expected to change as a result of the start year update. To ensure scenarios remain unchanged, transfer them to the stable version #2025-01 before August. See the documentation for more information.

Bug fixes

• The power shortage dashboard item showed an incorrect number for scenarios with household batteries, this also caused minor errors in the electricity price calculations. This issue is now fixed.
• Users who are not logged in can now download the profiles uploaded in public scenarios.
• A number of fixes to the password reset process and user emails have been made, this makes the process to reset the user passwords more user-friendly.

2025.05

New features

• Several improvements have been made to increase the speed of model calculations, contributing to a better overall user experience.
• Improvements in start year data of the Antwerp dataset have been made, related to transport and heating in the built environment. Consult the Dataset Manager to view this dataset.

2025.04

Stable version release 2025-01

The first stable version of the ETM is released, marking a major milestone for the model. Traditionally, the ETM has been under continuous development to capture the latest energy system modelling features, bug fixes and updates to datasets. The downside of this was that scenario settings, outcomes and dataset values could change over time. With the the stable version release, users now have the choice to work on the traditional and default version, #latest, or on the new and stable version, #2025-01.

The default and stable version of the model are at this moment exactly the same, but as #latest will continue to be under development, it will over time diverge from #2025-01. The release of the stable version does not affect any of the scenarios created before the release. For more information about stable versions and how to move scenarios to the stable version, see the documentation.

Note: the release of the stable version does not affect any of the scenarios created before the release.

Other new features

• It is now possible to download an overview of all slider settings of a scenario in the Data export section.
• Improvements of the start year data related to final demand in agriculture for the municipality of Noordoostpolder. Consult the Dataset Manager to view this dataset.
• Update of the chart "Final energy demand in other sector" where the carriers are now split into energetic and non-energetic (feedstock) demand.

Bug fixes

• There was an issue in modelling losses related to the treatment of natural gas extraction. This led to a mismatch between calculations for the annual and hourly natural gas balance and to an overestimation of natural gas imports in certain scenarios. This issue is now fixed.
• The charts in Collections that show the final demand ‘by carrier’ and ‘by sector by carrier’ were not aligned. This caused a discrepancy between these charts in the total final demand of Liquid biofuels and Oil and oil products. These charts have now been aligned to resolve this discrepancy.
• Greenhouse gas emissions from the Other sector were missing from the Greenhouse gas footprint visual. These are now included in the visual under Industry, Energy & Other.
• Under certain conditions, the forecasting algorithm for electricity storage caused invalid hourly electricity prices to emerge during curtailment. This issue is now fixed and the electricity price becomes 0 €/MWh in hours with curtailment.
• The electricity used in demand side response (DSR) in the central ICT sector was not taken into account in all calculations for final demand. This issue is now fixed.

Stable Release 2025.01

Released on the 4th of April, 2025.

2025.03

API Changes

• Version tags are now used for "Saved scenarios" and "Collections" in API responses
  (In preparation for releasing a stable version of the ETM).
  Read more about changes to the API in the API changelog.

UX and Account Management Improvements

• New setup of the "My Scenarios" and "My Account" pages.
• A central environment is introduced to manage:
  • Saved scenarios
  • Collections
  • Account settings
• Use this to:
  • Manage and share saved scenarios.
  • Generate Personal Access Tokens.
  • Subscribe to the newsletter.
  • Update personal information.

Collections (Previously "Transition Path Charts" / "Multi Year Charts")

• Renamed to "Collections".
• URL prefix changed from myc → collections.
• Definition updates:
  • A "Collection" is a set of saved scenarios that can be created in "My Scenarios".
  • A "Transition Path" is a specific type of "Collection", where a single saved scenario is interpolated to intermediate years.

New Charts

• Added to chart selection:
  • ‘Electricity supply and demand’
  • ‘Network gas supply and demand’

CO₂ Emissions Improvements

• Enhancements to non-energetic CO₂ emissions for better comparison between 1990, the start year, and future years.
• Updates to the ‘CO₂ emissions’ chart:
  • Splitting of non-energetic and delayed emissions into separate categories.
  • Updated chart descriptions regarding non-energetic emissions.
  • Updated documentation:
    • 1990 emissions
    • Modelled emissions in the ETM

Data & Scenario Updates

• Climate and Energy Outlook (KEV) 2024 added as a featured scenario for:
  • 2030 → View scenario
  • 2035 → View scenario
• Municipality of Emmen:
  • Improved start year data for chemical and other industry sectors.
• Antwerp dataset update:
  • Updated to start year 2022.

Technical Improvements

• Further enhancements to our automatic testing suite to improve model calculations.