NEMPulse · Glossary · Dispatch

SOC

Name: NEM Grid-Scale Battery Dispatch & Revenue Data
Creator: NEMPulse
License: https://creativecommons.org/licenses/by/4.0/

State of Charge — fill level relative to total registered capacity. 0% = empty, 100% = full. Primary source: energy storage reported by the unit in AEMO DISPATCHLOAD data (available next-day, shown in cyan). Where not yet reported, SOC is integrated from dispatch MW using ~85% round-trip efficiency (0.92 × 0.92), shown as a dotted line. Reported values above 105% are treated as data glitches and discarded.

State of Charge (SOC) is how full a battery is, expressed as a percentage of its registered energy capacity — 0% is fully discharged, 100% is fully charged. It is the constraint that ultimately limits how a battery can respond to price signals: it cannot discharge once empty, and cannot charge once full, regardless of how attractive the spot price is at that moment.

Where AEMO publishes a unit's reported energy storage directly (via DISPATCHLOAD, available the next day), NEMPulse uses that measured value. Where it is not yet available — most often for the most recent day or two of a selected range — SOC is instead integrated from dispatch MW using an assumed round-trip efficiency of roughly 85% (0.92 charging efficiency times 0.92 discharging efficiency), shown as a dotted rather than solid line so the two provenance tiers are visually distinct. Reported values above 105% are treated as data artefacts and discarded rather than plotted.