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Known issues

This section lists some known issues with SpineOpt.jl and possible workarounds.

Issue 1: Incompatible Julia version

Status: Identified Bug Affects: SpineOpt.jl is not compatible with Julia 1.12 Issue ID: #1274

Description

SpineOpt.jl requires Julia versions between 1.10.10 - 1.11. If you encounter compatibility issues, please ensure that you are using a supported Julia version. You can check your Julia version by running julia --version in your terminal.

Issue 2: Investment Variable Reporting with Mixed Temporal Block Configurations

Status: Identified Bug Affects: SpineOpt.jl investment optimization with flexible temporal resolution Issue ID: #1273

Description

When configuring a model with the same block appearing twice in temporal blocks—once with has_free_start = true and another with has_free_start = false—in combination with the unit lifetime constraints, investment-related variables are reported incorrectly. Specifically:

  • The units_invested variable consistently reports as 0, regardless of actual investments made
  • The units_mothballed variables fail to account for initial unit counts (existing_units)
  • Investment variables are aggregated and reported at annual resolution even when the investment block uses a different temporal resolution

Operational Impact: While the model's operational variables (dispatch, flows, etc.) calculate correctly, investment planning results are unreliable, making it unsuitable for multiyear capacity expansion studies with flexible temporal resolution.

Affected Scenarios

  • Multi-year investment planning without representative periods
  • Models using flexible temporal resolution across different nodes
  • Configurations mixing temporal blocks with different has_free_start parameters for the same block

Workaround

Currently under investigation. Until resolved, consider:

  1. Avoiding mixed temporal block configurations when unit lifetime constraints are active. For example, ensure that the same block is not included in both a block with has_free_start = true (e.g., for operation) and another with has_free_start = false (e.g., for investment).
  2. Using uniform temporal resolution for investment blocks (e.g., 10Y) to prevent using the same temporal block as the operational blocks (e.g., 1Y).
  3. Using consistent has_free_start settings across all temporal blocks containing the same block

Reproducibility

A minimal reproduction case is available in the issue tracker: reducedmodelflexible_resolution.json

Last Updated: Issue opened and currently open Tracking: https://github.com/spine-tools/SpineOpt.jl/issues/1273