Limit use of execute_load

[tonnrueter]

Purpose of this PR

Using execute_load to load values from GDX risks replacing symbol data entirely. Use execute_load only iff you want a clean slate for all attributes of a variable. In all other cases use execute_loadpoint to merge new data from a GDX into existing symbols while preserving it's attributes (i.e. bounds, levels, ..).

• Switch from execute_load to execute_loadpoint except for
• Usage in core/datainput.gms (lines 1627-1632) since there are no pre-existing values to preserve

Overview of the changes made:

File Path	Lines	Action	Reason
core/datainput.gms	1627-1632	Keep execute_load	Fresh initialization of reference parameters (p_prodSeReference, pm_prodFEReference, p_prodUeReference, p_co2CCSReference, pm_macCost) from scratch for comparison purposes. No pre-existing values to preserve.
core/preloop.gms	170	Switch to Execute_Loadpoint	Loading historical prices (t < cm_startyear) for pm_PEPrice, pm_SEPrice, pm_FEPrice. Future prices may already exist and should be preserved.
modules/21_tax/on/datainput.gms	153-154	Switch to Execute_Loadpoint	Loading baseline tax revenue parameters (pm_taxrevCO2LUC0, pm_taxrevGHG0). Should merge with existing baseline data.
modules/24_trade/se_trade/datainput.gms	189-190	Switch to Execute_Loadpoint	Loading reference demand values (p24_demFeForEsReference, p24_demFeIndSubReference). Should merge with existing reference data.
modules/29_CES_parameters/calibrate/datainput.gms	198	Switch to Execute_Loadpoint	Loading CES calibration data p29_cesdata_load from input.gdx. Should merge with existing calibration data.
modules/29_CES_parameters/calibrate/preloop.gms	29, 38	Switch to Execute_Loadpoint	Loading set mappings (ces2_29, regi_29_load) from input.gdx. Should merge with existing sets.
modules/30_biomass/magpie_40/datainput.gms	79	Switch to Execute_Loadpoint	Loading biomass cost data pm_pebiolc_costs_emu_preloop. Should merge with existing data.
modules/36_buildings/simple/datainput.gms	61	Switch to Execute_Loadpoint	Loading reference building demand p36_uedemand_build. Likely partial data that should be merged with existing data.
modules/37_industry/subsectors/datainput.gms	651	Switch to Execute_Loadpoint	Loading variable vm_demFeSector_afterTax. Variable bounds (.lo, .hi) should be preserved.
modules/37_industry/subsectors/datainput.gms	872	Switch to Execute_Loadpoint	Loading only .l attribute of v37_plasticWaste. Variable bounds should be preserved.

Please note that this might affect scenario results in unforeseen ways. Preliminary test runs:

• No changes, baseline run: /p/tmp/tonnru/clean_remind/output/SMIPv08-M-SSP2-NPi2025-def_2025-11-04_14.37.55
• Blanket replacement of execute_load, ✨ converged ✨: /p/tmp/tonnru/clean_remind/output/SMIPv08-M-SSP2-NPi2025-def_2025-11-04_18.02.35
• Partial replacement. Converged, but had INFES: /p/tmp/tonnru/clean_remind/output/SMIPv08-M-SSP2-NPi2025-def_2025-11-05_17.57.57
• Partial replacement, other scenario, ✨ converged ✨: /p/tmp/tonnru/clean_remind/output/SMIPv08-ML-SSP2-EcPrice300-def_2025-11-05_22.51.01

Please suggest further scenarios to be tested!

Type of change

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Do not delete any lines. This makes it easier to understand which areas are affected by your changes and which are not.

Parts concerned

• ☑️ GAMS Code
• ◻️ R-scripts
• ◻️ Documentation (GAMS incode documentation, comments, tutorials)
• ◻️ Input data / CES parameters
• ◻️ Tests, CI/CD (continuous integration/deployment)
• ◻️ Configuration (switches in main.gms, default.cfg, and scenario_config*.csv files)
• ◻️ Other (please give a description)

Impact

• ◻️ Bug fix
• ☑️ Refactoring
• ◻️ New feature
• ◻️ Change of parameter values or input data (including CES parameters)
• ◻️ Minor change (default scenarios show only small differences)
• ◻️ Fundamental change of results of default scenarios

Checklist

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In the end all checkboxes must be ticked before you can merge.

• I executed the automated model tests (make test) after my final commit and all tests pass (FAIL 0)
• I adjusted the reporting in remind2 if and where it was needed
• I adjusted the madrat packages (mrremind and other packages involved) for input data generation if and where it was needed
• My code follows the coding etiquette
• I explained my changes within the PR, particularly in hard-to-understand areas
• I checked that the in-code documentation is up-to-date
• I adjusted forbiddenColumnNames in readCheckScenarioConfig.R in case the PR leads to deprecated switches
• I updated the CHANGELOG.md correctly (added, changed, fixed, removed, input data/calibration)

Further information (optional)

• Runs with these changes are here:
• Comparison of results (what changes by this PR?):

[LaviniaBaumstark]

looks good. Did I get it right, that not all testruns did work? Could you provide a link to a compareScenarios for before and after your changes?

[tonnrueter]

looks good. Did I get it right, that not all testruns did work? Could you provide a link to a compareScenarios for before and after your changes?

Please find attached the compareScenario summary. Some observations
Uploading compScen-compScen-base_blanket_partial--2025-11-10_12.23.29-summary.pdf…

• Some differences in the FE pCap variable after 2060 for the different runs (p.24ff)
• Price|Carbon (p. 50) seem identical

[LaviniaBaumstark]

sorry, where is the compareScenario.pdf file?