gtopt/battery.hpp file

Header for battery energy storage components.

This module defines data structures for representing battery energy storage systems (BESS) in power system planning models. A battery stores and releases electrical energy between time blocks, subject to capacity and efficiency constraints. It is coupled to the electrical network through a Converter that links it to a discharge Generator and a charge Demand.

Standalone battery (unified definition)

When the optional bus field is set (without source_generator), the system automatically generates the associated Generator (discharge path), Demand (charge path), and Converter during preprocessing — no separate elements are needed. Both charge and discharge connect to the same external bus:

{
  "uid": 1,
  "name": "bess1",
  "bus": 3,
  "input_efficiency": 0.95,
  "output_efficiency": 0.95,
  "emin": 0,
  "emax": 100,
  "capacity": 100,
  "pmax_charge": 60,
  "pmax_discharge": 60,
  "gcost": 0
}

Generation-coupled battery (hybrid / behind-the-meter)

When both bus and source_generator are set, the battery is in generation-coupled mode: the source_generator directly feeds the battery charge path through an auto-created internal bus. System::expand_batteries() will:

Create an internal bus (name = battery.name + "_int_bus")
Connect the discharge Generator to the external bus
Connect the charge Demand to the internal bus
Set the source_generator's bus to the internal bus

The source_generator should have no bus set, or its bus will be overwritten with the internal bus.

{
  "uid": 1,
  "name": "bess1",
  "bus": 3,
  "source_generator": "solar1",
  "input_efficiency": 0.95,
  "output_efficiency": 0.95,
  "emin": 0,
  "emax": 100,
  "capacity": 100,
  "pmax_charge": 60,
  "pmax_discharge": 60,
  "gcost": 0
}

Traditional multi-element definition

Without the bus field, a separate Converter, Generator, and Demand must be defined manually to couple the battery to the electrical network:

{
  "uid": 1,
  "name": "bess1",
  "input_efficiency": 0.95,
  "output_efficiency": 0.95,
  "emin": 0,
  "emax": 100,
  "capacity": 100
}

Fields that accept a number/array/string value can hold:

A scalar constant
A 1-D inline array indexed by [stage]
A filename string referencing a Parquet/CSV schedule in input_directory/Battery/

Namespaces

namespace gtopt

Classes

struct gtopt::Battery: Represents a battery energy storage system (BESS)