eflips-impact

eflips-impact is part of the eFLIPS tool family for electric bus fleet simulation. It provides two impact analysis modules operating on eFLIPS simulation results:

• TCO — Total Cost of Ownership, including capital expenditure (vehicles, batteries, charging infrastructure) and operational expenditure (energy, staff, maintenance, insurance, taxes).
• LCA — Life Cycle Assessment of greenhouse gas emissions (GWP, kg CO₂-eq), following ISO 14040/14044. Functional unit: revenue-kilometre (Nutzwagenkilometer).

Both modules read simulation data from an eFLIPS database and accept scenario parameters from JSON configuration files.

Installation

From PyPI

pip install eflips-impact

From source

git clone https://github.com/mpm-tu-berlin/eflips-impact.git
cd eflips-impact
pip install .

For development (includes linting, type checking, and docs tools):

pip install -e ".[dev]"

Python version: 3.10 – 3.13.

Quick start

Two example scripts under bin/ demonstrate the full pipeline end-to-end.

TCO example

python bin/example_tco.py

Runs the following steps:

1. Initialises fleet topology (battery types, charging point types) from fleet.json.
2. Writes TCO parameters to the database from tco.json.
3. Calculates TCO and prints a per-category cost table (EUR / revenue-km).
4. Saves a stacked bar chart to tco_by_type.png.

LCA example

python bin/example_lca.py

Runs the following steps:

1. Initialises fleet topology from fleet.json.
2. Writes LCA parameters to the database from lca.json and lca_overrides.json.
3. Calculates LCA and prints GWP results by lifecycle scope and component type.
4. Saves charts to lca_by_scope.png and lca_by_type.png.

Before running, set the DATABASE_URL variable at the top of each script (or via the DATABASE_URL environment variable) to point to a populated eFLIPS simulation database.

Input data

eflips-impact requires two types of input:

1. eFLIPS simulation data

A PostgreSQL database produced by an eFLIPS simulation run, containing VehicleType, Trip, Route, Event, Area, Station, and related tables. The database URL is passed to all entry-point functions via database_url or the DATABASE_URL environment variable.

2. JSON parameter files

Scenario-specific parameters are supplied through four JSON files. Example files for all four are provided under eflips/impact/defaults/example/:

Copy and adapt the example files to your scenario. The matching between JSON entries and database rows uses string keys (name_short for vehicle types, type for charging infrastructure) — never database-assigned integer IDs.

Calculation workflow

eFLIPS simulation DB
        │
        ▼
  complete_fleet()                        ← fleet.json
  (creates BatteryType /
   ChargingPointType rows)
        │
        ├─────────────────────────────────────────┐
        │                                         │
        ▼                                         ▼
  init_tco_params()  ← tco.json     init_lca_params()  ← lca.json
  (writes tco_parameters                (writes lca_parameters          + lca_overrides.json
   to DB entities)                       to DB entities)
        │                                         │
        ▼                                         ▼
  calculate_tco()                       calculate_lca()
        │                                         │
        ▼                                         ▼
   TCOResult                              LCAResult

complete_fleet() must be called once before the parameter-init functions. The two parameter-init steps (init_tco_params, init_lca_params) and the two calculation steps are independent and can be run separately.

Public API

from eflips.impact.utils import complete_fleet
from eflips.impact.tco import init_tco_params, calculate_tco
from eflips.impact.lca import init_lca_params, calculate_lca

# 1. Fleet topology
complete_fleet(scenario=1, json_path="fleet.json", delete_existing_data=True, database_url=DATABASE_URL)

# 2a. TCO parameters
init_tco_params(scenario=1, json_path="tco.json", database_url=DATABASE_URL)

# 2b. LCA parameters
init_lca_params(scenario=1, lca_json_path="lca.json", overrides_json_path="lca_overrides.json",
                database_url=DATABASE_URL)

# 3. Calculate
tco_result = calculate_tco(scenario=1, database_url=DATABASE_URL)
lca_result = calculate_lca(scenario=1, database_url=DATABASE_URL)

# 4. Results
print(tco_result.tco_per_revenue_km)  # EUR / revenue-km
print(lca_result.total_per_revenue_km.gwp)  # kg CO₂-eq / revenue-km

# 5. Plots
tco_result.plot(use_revenue_km=True, save_path="tco.png")
lca_result.plot_by_scope(save_path="lca_scope.png")
lca_result.plot_by_type(save_path="lca_type.png")

Development

# Format
black eflips/

# Type check
mypy eflips --explicit-package-bases --strict

# Tests
pytest

License

See LICENSE.