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Output Overview

EPM produces several types of output after each run: raw model results, processed CSVs, figures, and summaries.

Output categories

EPM outputs are organized into thematic categories. Each maps to a set of variables in the Output Catalog.

Category What it covers
Capacity & Transmission Installed capacity by plant/fuel/zone/year, new builds, retirements, transfer limits
Energy & Dispatch Annual generation by plant/fuel, hourly dispatch, energy balance
Costs & Investment CAPEX, operating costs, NPV system cost, marginal prices
Utilization Capacity factors by plant, fuel, technology
Reserves Spinning reserve provision, capacity credits
Interconnection Cross-border flows, congestion rents, interconnector utilization
Emissions CO₂ by zone, emissions intensity
Financial LCOE per plant, average system cost per MWh
Fuel Delivered fuel price trajectories

Output formats

Format Files Description
GDX epmresults.gdx Complete binary results written by GAMS. Contains all output variables.
CSV output_csv/*.csv 10 analysis-ready files produced by the postprocessing pipeline (see below).
Figures img/ · EPM Dashboard PNG plots auto-generated by category; also viewable interactively in the Dashboard.
Summaries summary.csv · summary_generators.csv Aggregated key metrics across scenarios.

REPORTSHORT flag

When REPORTSHORT = 1 in pSettings.csv, only three variables are exported (pCosts, pCostsFull, pEnergyBalance). The full catalog assumes the default REPORTSHORT = 0.

Folder structure

Each run creates a timestamped folder under epm/output/:

simulations_run_<timestamp>/
│
├── baseline/                    # Scenario folders (e.g. baseline, HighDemand)
│   ├── output_csv/              # CSVs merged for dashboard
│   ├── epmresults.gdx           # Comprehensive raw data
│   └── input_version/           # Input data snapshot
│
├── img/                         # Auto-generated figures
│
├── summary.csv                  # Summary CSVs
├── summary_generators.csv
└── input_scenarios.csv

Postprocessing pipeline

After GAMS completes, EPM automatically runs a 10-step Python pipeline (output_treatment.py) that transforms raw GAMS outputs into analysis-ready files:

  1. Rename columns for compatibility
  2. Merge plant files with generator tech-fuel mapping
  3. Fill missing tech-fuel combinations
  4. Build complete dispatch tables
  5. Fill cost components
  6. Calculate cumulative values
  7. Create merged CSV files (see below)
  8. Add country columns to zone-based files
  9. Restructure and sort files
  10. Delete intermediate files: only the 10 final files are kept in output_csv/

Output CSV files

After the pipeline, output_csv/ contains exactly 10 files:

File What it consolidates Key dimensions
pTechFuelMerged.csv Capacity, energy, utilization, reserves by technology and fuel zone · tech · fuel · year
pPlantMerged.csv Capacity, energy, costs, LCOE by individual plant zone · plant · year
pYearlyCostsMerged.csv Zone-level costs, discounted costs, cost per MWh zone · year
pTransmissionMerged.csv Flows, utilization, capacity, congestion, net imports zone pair · year
pYearlyZoneMerged.csv Demand, emissions, intensity, prices by zone and year zone · year
pCostsSystemMerged.csv System NPV costs and cost per MWh system · year
pCapexInvestmentMerged.csv CAPEX by component, including cumulated values zone · year
pDispatchComplete.csv Full hourly dispatch by tech and fuel zone · tech · fuel · period
pPrice.csv Marginal price signals by zone and period zone · period
pSettings.csv Scenario settings captured at run time —

The raw, unprocessed results remain accessible at any time in epmresults.gdx.

Multi-scenario runs

When running multiple scenarios, EPM processes them in parallel and consolidates results automatically:

  • Each scenario gets its own subfolder (e.g. baseline/, high_demand/, low_fuel/) with its own output_csv/.
  • Figures in img/ cover all scenarios. Cross-scenario comparisons appear at the top level.
  • summary.csv and summary_generators.csv aggregate key indicators across all scenarios into a single file.
  • input_scenarios.csv tracks the configuration of every scenario run.