Battery

The epl.Battery model is suitable for modelling an electric battery, such as a lithium-ion battery.

The battery charge rate is defined by power_mw, which defines both the maximum rate of charge and discharge. discharge_power_mw can be used to define a different rate of maximum discharge.

The battery storage capacity is defined by capacity_mwh. This should be the capacity after taking into account any battery depth of discharge limits.

An efficiency penalty is applied to the battery charge energy, based on the efficiency_pct parameter. No electricity is lost when discharging or during storage.

initial_charge_mwh and final_charge_mwh control the battery state of charge at the start and end of the simulation. These can cause infeasible simulations if the battery is not able to charge or discharge enough to meet these constraints.

You can check the correctness of the battery model here.

import energypylinear as epl

asset = epl.Battery(
    power_mw=2,
    discharge_power_mw=2,
    capacity_mwh=4,
    efficiency_pct=0.9,
    electricity_prices=[100.0, 50, 200, -100, 0, 200, 100, -100],
    freq_mins=60,
    initial_charge_mwh=1,
    final_charge_mwh=3,
    name="battery"
)
simulation = asset.optimize()

assert all(
    simulation.results.columns
    == [
        "site-import_power_mwh",
        "site-export_power_mwh",
        "site-electricity_prices",
        "site-electricity_carbon_intensities",
        "site-high_temperature_load_mwh",
        "site-low_temperature_load_mwh",
        "site-low_temperature_generation_mwh",
        "site-gas_prices",
        "site-electric_load_mwh",
        "spill-electric_generation_mwh",
        "spill-electric_load_mwh",
        "spill-high_temperature_generation_mwh",
        "spill-low_temperature_generation_mwh",
        "spill-high_temperature_load_mwh",
        "spill-low_temperature_load_mwh",
        "spill-gas_consumption_mwh",
        "battery-electric_charge_mwh",
        "battery-electric_charge_binary",
        "battery-electric_discharge_mwh",
        "battery-electric_discharge_binary",
        "battery-electric_loss_mwh",
        "battery-electric_initial_charge_mwh",
        "battery-electric_final_charge_mwh",
        "total-electric_generation_mwh",
        "total-electric_load_mwh",
        "total-high_temperature_generation_mwh",
        "total-low_temperature_generation_mwh",
        "total-high_temperature_load_mwh",
        "total-low_temperature_load_mwh",
        "total-gas_consumption_mwh",
        "total-electric_charge_mwh",
        "total-electric_discharge_mwh",
        "total-spills_mwh",
        "total-electric_loss_mwh",
        "site-electricity_balance_mwh",
    ]
)