Parameters & Scenarios¶
Parameters control the global settings of the optimization: the time horizon, solver choice, and objective function. Scenarios are named sets of parameter overrides that let you run what-if analyses without duplicating the entire model.
Parameters¶
Navigate to the Parameters tab to configure the following:
Time settings¶
| Parameter | Description |
|---|---|
| Start date | Beginning of the model time horizon (inclusive). Format: YYYY-MM-DD. |
| End date | End of the model time horizon (inclusive). Format: YYYY-MM-DD. |
| Time resolution | Step size as a pandas offset string: 1H (hourly), 30min, 1D, etc. |
Reducing model size
For exploratory runs use a short time horizon (e.g. one week at hourly resolution). Scale to a full year only when the model structure is validated.
Solver settings¶
| Parameter | Default | Description |
|---|---|---|
| Solver | glpk |
LP solver backend. Options: glpk, gurobi, cplex, cbc. The selected solver must be installed in the Python environment. |
| Solver options | (none) | Key-value pairs passed directly to the solver (e.g. mipgap: 0.01). |
| Verbosity | True |
When enabled, solver progress is written to the run log. |
Objective function¶
| Parameter | Default | Description |
|---|---|---|
| Objective | minize_cost |
Calliope objective function. Leave as default unless you have a custom objective defined in the override block. |
Scenarios¶
Scenarios apply a named set of parameter overrides on top of the base model at run time. They are the Calliope way of exploring different assumptions without maintaining separate model files.
Creating a scenario¶
- Go to the Scenarios tab.
- Click Add Scenario.
- Give it a name (e.g.
high_carbon_price). - Add one or more overrides — each override is a dot-separated Calliope parameter path and a new value:
techs.gas_ccgt.costs.monetary.cost_om_prod = 0.08
techs.solar_pv.costs.monetary.cost_energy_cap = 400
- Click Save.
Running a specific scenario¶
In the Run screen, select the scenario from the Scenario dropdown before clicking Start. If no scenario is selected, the base model parameters are used.
Overrides¶
The Overrides tab provides a raw YAML text editor for injecting arbitrary Calliope override blocks. This is intended for advanced users who need to express model features not exposed in the UI forms.
The content of this block is appended verbatim to the exported YAML under the overrides key. Invalid YAML will cause the export and the run to fail.