“battery”

Batteries store energy for later use or export at a profit:

"battery": {
    "include": true,
    "initial_raw_capacity_kwh": 13.5,
    "cost_install_gbp": 5000.0,
    "max_charge_kw": 6.4,
    "max_discharge_kw": 6.4,
    "cost_maintenance_pa_gbp": 0,
    "round_trip_efficiency_percent": 93,
    "projection": {
      "cycles_to_reduced_capacity": 7500,
      "reduced_capacity_percent": 20
    }    
  },

“initial_raw_capacity_kwh” gives the battery’s initial capacity at the beginning of the project.

Include your battery’s maximum charge in discharge powers in “max_charge_kw” and “max_discharge_kw” respectively. All batteries, especially those couple to AC inverters, lose some power when charging and discharging, so you need to state the round trip efficiency in “round_trip_efficiency_percent”.

“gbp” is the intial cost including installation. If your battery requires annual maintenance (few do) put this in “gbp_per_year”.

The simulator assumes battery capacity reduces linearly with charge-discharge cycles. For your stated “initial_raw_capacity_kwh”, state the “reduced_capacity_percent” and “cycles_to_reduced_capacity”. I.e. in the above example, capacity reduces to 0.8 * 13.5 kWh (10.8 kWh) after 7,500 cycles.

Behaviour

The simulator attempts to satisfy the house load:

• from the battery, then

• from the grid.

The simulator assumes the battery charges as much as possible:

• from solar generation, then

• from the grid during off peak periods