Costing

PsCosting computes CAPEX/OPEX breakdowns and levelized costs from costing blocks in simulation data.

Overview

The costing tool works with PsDataManager to:

1. Import costing block data from HDF5 files
2. Group devices into user-defined categories
3. Compute CAPEX, OPEX, and energy costs per group
4. Calculate levelized costs (e.g., LCOW — Levelized Cost of Water)

Defining Device Groups

Device groups map logical names to simulation unit names:

device_groups = {
    "RO": {"units": "ROUnits"},
    "Pumps": {
        "CAPEX": {
            "units": {"PrimaryPumps", "BoosterPumps", "EnergyRecoveryDevices"}
        },
        "OPEX": {
            "units": {"PrimaryPumps", "BoosterPumps", "EnergyRecoveryDevices"}
        },
    },
}

Group Structure

• Simple groups: {"units": "UnitName"} — same units for CAPEX and OPEX
• Split groups: Separate "CAPEX" and "OPEX" sub-dicts with different unit sets

Using PsCosting via PsDataManager

The simplest way is through PsDataManager.get_costing():

from psPlotKit.data_manager.ps_data_manager import PsDataManager

dm = PsDataManager("my_results.h5")
dm.load_data([
    {"filekey": "fs.water_recovery", "return_key": "Water recovery", "units": "%"},
])

dm.get_costing(device_groups)

get_costing Parameters

Parameter	Default	Description
costing_groups	—	Device group definitions (see above)
costing_block	"fs.costing"	Root costing block in simulation
costing_key	"costing"	Sub-key for costing data
default_flow	"fs.product.properties[0.0].flow_vol_phase[Liq]"	Flow variable for levelized cost
work_keys	["control_volume.work[0.0]"]	Energy consumption keys
include_indirect_in_device_costs	True	Include indirect costs in device totals

Plotting Cost Breakdowns

After computing costing, use BreakDownPlotter:

from psPlotKit.data_plotter.ps_break_down_plotter import BreakDownPlotter

dm.reduce_data(
    stack_keys="number_of_stages",
    data_key="LCOW",
    reduction_type="min",
)
dm.select_data(["stacked_data"], True)
selected = dm.get_selected_data()

plotter = BreakDownPlotter(selected)
plotter.define_area_groups({"RO": {}, "Pumps": {}})
plotter.define_hatch_groups({"CAPEX": {}, "OPEX": {"hatch": "//"}})
plotter.plotbreakdown(
    xdata="Water recovery",
    ydata=["cost_breakdown", "levelized"],
    axis_options={"yticks": [0, 0.5, 1.0, 1.5, 2.0]},
)