The battery model
How usable energy, round-trip efficiency, C-rate and state of charge combine to decide how much energy the battery can move at each step.
At every step of the dispatch model, three battery properties decide how much energy can move and how much of it survives the round trip: how much of the pack's nameplate energy is usable right now, how much of a full charge/discharge cycle comes back out as delivered energy, and how fast the pack can move energy in or out. This page is those three, plus the state-of-charge tracking that ties them together across a run.
Usable energy
usable energy = nameplate energy × DoD × SOHDoD — depth of discharge — is the fraction of nameplate energy usable per cycle; not every kWh of a pack's rating is meant to be cycled. SOH — state of health — is the battery's remaining capacity relative to nameplate as it ages, starting from an initial value at commissioning and falling over the project life; see Degradation, EOL and augmentation for how that curve is shaped. Nameplate energy itself doesn't change between the two — it's DoD and SOH together that decide how much of it the dispatch model can actually draw on at a given point in the project.
Round-trip efficiency
RTE — round-trip efficiency — is the share of energy recovered from one full charge/discharge cycle, including auxiliary losses. Because a full cycle has two legs, charging in and discharging out, the model applies the square root of the round-trip figure to each leg separately rather than the whole figure to just one — so the two legs' losses compound back to the full round-trip figure you entered, over one complete cycle.
C-rate
C-rate is the battery's power-to-energy sizing ratio, power divided by energy (MW ÷ MWh). It caps how fast the pack can move energy in a single step: in the Standalone dispatch rule, for instance, the Off-Peak grid recharge is capped by both the C-rate ceiling and however much headroom the pack has left. See How dispatch works for where that applies.
State of charge across a run
Every run of the dispatch model starts the battery at 100% state of charge, and each step's charge or discharge — decided by whichever dispatch rule governs that run — moves it from there. Usable energy and round-trip efficiency apply the same way regardless of which dispatch rule is active: they describe the battery itself, not the rule deciding when it charges or discharges. C-rate sets a ceiling wherever a dispatch rule draws on it, as in the Standalone example above.
See Battery parameters for the Depth of Discharge, Initial State of Health, Round-Trip Efficiency and C-Rate fields, their defaults and their ranges.
Where to go next
Delivery Fulfilment Ratio (DFR)
What DFR measures at each granularity, how its five targets are set, and how a shortfall becomes a financial penalty.
Degradation, EOL and augmentation
The battery's SOH curve, end-of-life by years or cycles, replacement vs augmentation, and how it differs from generation degradation.