Introduction
This document outlines the data requirements for the TWAICE Energy Analytics platform. It specifies the supported BESS data model hierarchy, required sensor inputs and data resolution for best quality.
The customer’s cooperation and fulfillment of the outlined requirements are essential for the full delivery of TWAICE products and services.
Supported Battery Chemistries
TWAICE Energy Analytics platform is available for all common lithium-ion cell chemistries, listed below.
NMC/NCM (Lithium Nickel Manganese Cobalt Oxide)
NCA (Lithium Nickel Aluminium Cobalt Oxide)
LMO (Lithium Manganese Oxide)
LCO (Lithium Cobalt Oxide)
LNMO (Lithium Nickel Manganese Oxide)
LFP (Lithium Iron Phosphate)
BESS Data Model Components
Battery Energy Storage Systems (BESS) follow a hierarchical structure of components and sensors.
TWAICE uses hierarchy types to better represent how BESS systems are both electrically wired and physically organized. Below, a typical BESS data model components supported by TWAICE is given.
Physical Levels:
Name | Common Alternative Names | Definition |
Site | Plant | Used for grouping of multiple BESS, and other energy systems, such as wind and solar, at the same site. |
Enclosure | Container, Cluster | Represents the physical housing unit that contains key electrical and battery components such as racks, PCS modules, and auxiliary systems (e.g., HVAC, fire suppression). |
👉 Physical hierarchy can contain any of the electrical components (explained below) within “enclosures”.
Electrical Levels:
Name | Common Alternative Names | Definition |
System | Storage, System | Represents the complete BESS installation as a single operational unit. Includes all electrical and control subsystems required for operation. |
Meter | AUX Meter, Power Meter, Measurement Point | Device or logical point used for measuring electrical parameters (e.g., power, energy, voltage). Often corresponds to utility or submetering equipment. |
Transformer | Step-up Transformer, MV Transformer | Converts AC voltage levels between the grid and the BESS system (typically low-voltage to medium-voltage). Key interface between site and utility. |
AC Combiner | Cluster, AC Junction Box, AC Panel, AC Blok, Blok | Aggregates AC outputs from multiple PCS units to the transformer or grid interface. |
PCS | Inverter, Power Conversion System | Converts DC power from batteries to AC power for the grid, and vice versa. Typically consists of multiple PCS modules. |
PCS Module | Inverter Module, Power Block | Subcomponent of the PCS representing an individual module. Allows fine-grained monitoring and control. |
DC Combiner | Node, DC Junction Box, DC Panel, DC Box, Array, BSU | Combines multiple DC inputs from racks to the PCS Module(s). Used for current collection and protection. |
Rack Group | String Group, DC Branch, Battery Bank | Logical grouping of multiple battery racks, used for monitoring or control aggregation. |
Rack PCS | PCS Rack, Converter Rack, String PCS | Battery rack directly associated with a PCS input. Represents DC paths linked to specific converters. |
Rack | String, Pack | A chain of modules electrically connected in series or parallel. Commonly represents a container’s internal substructure. |
Rack Module PCS | PCS Battery Module, Converter Module, String Module PCS | Module within a rack that is directly associated with PCS-specific connections or control paths. |
Rack Module | Battery Module, Rack Module, String Module | A standard unit of connected cells forming part of a rack; often includes integrated BMS and monitoring electronics. |
Cell | Battery Cell | The smallest electrochemical unit containing active materials. Fundamental energy-storing component of the BESS. |
❗Notes:
Customers can customize naming of the component levels.
Customers may define additional hierarchy levels, any such custom additional levels are not included in TWAICE’s standard may not be reflected in the platform.
BESS Sensor Requirements
To enable the features of TWAICE Energy Analytics platform, a minimum set of sensor data should be provided by the customer. These sensors are essential to calculate key battery performance and health indicators such as SoC, SoH, and EFC.
We recommend the following minimum sensor inputs to be shared with TWAICE:
Sensor Data Resolution
While KPIs can be generated from a variety of data resolutions, higher fidelity data results in more precise calculations for battery performance and health.
The accuracy of performance and health KPIs may vary depending on the time and data resolution provided by the customer.
For optimal results, we require raw, high-resolution time series data (not down-sampled) from your BESS telematics system.
From battery time series data collected by your telematics system, we require the following parameters with the indicated resolution listed below.
Data Logging
Understanding your data logging method is critical for both accurate monitoring and diagnosis of any data inconsistencies.
❗This information should be shared with TWAICE before ingestion of data begins.
🔁 On-Change Logging
If the system logs data only when a value changes, please provide:
Heartbeat of those sensors ( TWAICE requires at least 10 minute heartbeat on all sensors)
Minimum expected value
Maximum expected value
Default value indicating invalid reading
📈 Continuous Logging
If data is logged at a fixed interval, please provide:
Native readings or aggregation (min/max/average)
Logging frequency
Minimum expected value
Maximum expected value
Default value indicating invalid reading
❗Note: Regardless of logging type, please inform TWAICE of any known or potential data gaps.
Additional Data Pattern Requirements
Time series data should reflect the following patterns for best quality of TWAICE KPIs provision.
Minimum of 30 full charge/discharge cycles required before SoC and SoH estimations can be generated.
Data should include all BESS operating states: charging, discharging, and resting.
BESS should be in regular operation (more than 200 Equivalent Full Cycles (EFC) annually).
Data gaps should be avoided, as they can affect KPI quality, particularly for EFC, throughput, SoC, and SoH.
Continuous data logging is recommended (see options above).
TWAICE Calculated KPIs
📘 For a complete list of KPIs calculated by TWAICE and delivered in Energy Analytics platform, please refer to the following article: Guide to TWAICE KPIs.