Guide to TWAICE KPIs
Browse all TWAICE-calculated KPIs available on the platform, with a summary overview and a detailed description of each one.
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The table below describes all the available, TWAICE-calculated KPIs which can be accessed through the TWAICE Energy Analytics platform, including delivered in which platform feature (e.g. Reports, Performance Manager) and required sensors to calculate that KPI.
All of these KPIs are based on raw data coming from the BESS and leverage TWAICE raw data pre-processing and KPI-specific algorithms and models developed by TWAICE internally.
These KPIs are by standard daily aggregations. Daily KPIs are defines as: daily from 00:00:00UTC until 23:59:59.99UTC
Summary Outlook:
Detailed List:
| KPI Name / Unit | Level | Description | Platform Feature | Required Input Sensor |
| SoH - ref. Installed DC Energy SoH [%] Operational data needed (1-30 cycles) | System & String | State of Health using installed DC Energy as a reference. Installed DC Energy is using a bottom up approach from the cell up to define the total installed energy. On system level, aggregated state of health across all strings, calculated from individual string SoH values | Warranty Reports Performance - Recoverable Energy Health Data Explorer | String Current String Voltage String Temperature String Min Cell Voltage String Max Cell Voltage |
| SoH - ref. Equipment DC Energy SoH [%] Operational data needed (1-30 cycles) | System & String | State of Health using Equipment DC Energy as a reference. Equipment DC Energy is defined during the TWAICE onboarding process for the system. For the string level, the system Equipment DC Energy is divided by the number of strings. On system level, aggregated state of health across all strings, calculated from individual string SoH values | Warranty Data Explorer Reports | String Current String Voltage String Temperature String Min Cell Voltage String Max Cell Voltage |
| SoH - Energy-based SoH [MWh / kWh] Operational data needed (1-30 cycles) | System & String | State of Health focusing on the still usable energy and displaying the amount of energy directly. On system level, aggregated state of health across all strings, calculated from individual string SoH values | Health Warranty Reports | String Current String Voltage String Temperature String Min Cell Voltage String Max Cell Voltage |
| DC Resistance Resistance [Ω] Operational data needed (1-30 cycles) | String | DC resistance of a full string, which may be influenced by cable connections or faults in components like cells. | Health Safety Data Explorer Reports | String Current String Voltage String Temperature |
| DC Resistance Confidence Interval Upper Bound Resistance [Ω] Operational data needed (1-30 cycles) | String | Upper bound of the confidence interval for string DC resistance. | Health Data Explorer | String Current String Voltage String Temperature |
| DC Resistance Confidence Interval Lower Bound Resistance [Ω] Operational data needed (1-30 cycles) | String | Lower bound of the confidence interval for string DC resistance. | Health Data Explorer | String Current String Voltage String Temperature |
| SoC SoC [%] Operational data needed (1-30 cycles) | String | State of charge of an individual string, calculated using voltage, current, and temperature inputs and based on the TWAICE SoC model. | Performance - Imbalance Health Data Explorer Reports | String Current String Voltage String Temperature String Min Cell Voltage String Max Cell Voltage |
| Cell SoC Max SoC [%] Operational data needed (1-30 cycles) | String | Maximum SoC in a string, derived from the maximum cell voltage within the string and based on the TWAICE SoC model. | Performance - Imbalance Data Explorer | String Current String Max Cell Voltage String Min Cell Voltage String Temperature |
| Cell SoC Min SoC [%] Operational data needed (1-30 cycles) | String | Minimum SoC in a string, derived from the minimum cell voltage within the string and based on the TWAICE SoC model. | Performance - Imbalance Data Explorer | String Current String Min Cell Voltage String Max Cell Voltage String Temperature |
| Cell SoC Spread SoC [%] Available when data connection established | String | Difference between max and min SoC in a string, indicating internal imbalances. | Performance - Imbalance Data Explorer Reports | String Current String Max Cell Voltage String Min Cell Voltage String Max Cell Voltage String Temperature |
| Self-Discharge Voltage [V] Available when data connection established | String | Classification if the min cell voltage of a cell within a string is drifting away | Safety | String Min Cell Voltage |
| Energy Throughput charge (daily/ cumulative) Energy [Wh] Available when data connection established | String | Total charged energy throughput per string, tracked daily and cumulatively. | Data Explorer Reports | String Current String Voltage |
| Energy Throughput discharge (daily/ cumulative) Energy [Wh] Available when data connection established | String | Total discharged energy throughput per string, tracked daily and cumulatively. | Data Explorer Reports | String Current String Voltage |
| Energy Throughput net (daily/ cumulative) Energy [Wh] Available when data connection established | String | Net energy throughput (charge minus discharge) of a string, tracked daily and cumulatively. | Data Explorer | String Current String Voltage |
| Energy Throughput absolute (daily/ cumulative) Energy [Wh] Available when data connection established | String | Absolute energy throughput of a string, summing all energy flows regardless of direction. | Data Explorer Reports | String Current String Voltage |
| Capacity Throughput charge (daily/ cumulative) Charge [Ah] Available when data connection established | String | Total charged capacity throughput in Ah for a string, tracked daily and cumulatively. | Data Explorer | String Current |
| Capacity Throughput discharge (daily/ cumulative) Charge [Ah] Available when data connection established | String | Total discharged capacity throughput in Ah for a string, tracked daily and cumulatively. | Data Explorer | String Current |
| Capacity Throughput net (daily/ cumulative) Charge [Ah] Available when data connection established | String | Net capacity throughput in Ah for a string (charge minus discharge), tracked daily and cumulatively. | Data Explorer | String Current |
| Capacity Throughput absolute (daily/ cumulative) Charge [Ah] Available when data connection established | String | Sum of all charge and discharge capacity throughputs for a string in Ah, tracked daily and cumulatively. | Data Explorer | String Current |
| Equivalent Full Cycles (daily/ cumulative) Counter [-] Available when data connection established | String | Number of full equivalent charge/discharge cycles per string (0% to 100% and back), tracked daily and cumulatively. | Health Warranty Data Explorer | String Current |
| Equivalent Full Charge Cycles (daily/ cumulative) Counter [-] Available when data connection established | String | Full charge cycles per string, calculated from 0% to 100% SoC transitions, tracked daily and cumulatively. | Data Explorer | String Current |
| Equivalent Full Discharge Cycles (daily/ cumulative) Counter [-] Available when data connection established | String | Full discharge cycles per string, calculated from 100% to 0% SoC transitions, tracked daily and cumulatively. | Data Explorer | String Current |
| Equivalent Energy Cycles (daily/ cumulative) Counter [-] Available when data connection established | String | Equivalent full energy cycles based on energy throughput (Wh) from 0% to 100% SoC and back, tracked daily and cumulatively. | Data Explorer | String Current String Voltage |
| Equivalent Energy Charge Cycles (daily/ cumulative) Counter [-] Available when data connection established | String | Equivalent full charge energy cycles, based on energy throughput (Wh) from 0% to 100% SoC, tracked daily and cumulatively. | Data Explorer | String Current String Voltage |
| Equivalent Energy Discharge Cycles (daily/ cumulative) Counter [-] Available when data connection established | String | Equivalent full discharge energy cycles, based on energy throughput (Wh) from 100% to 0% SoC, tracked daily and cumulatively. | Data Explorer | String Current String Voltage |
| Cell Voltage Spread Voltage [V] Available when data connection established | String | Voltage difference between the highest and lowest cell voltage in a string, showing internal string imbalance. | Performance - Imbalance Health System Monitor Data Explorer | String Max Cell Voltage String Min Cell Voltage |
| Module Temperature Spread Temperature [°C] Available when data connection established | String | Difference between the highest and lowest module temperatures within a string, showing thermal imbalance. | Performance - Temperature Health System Monitor Data Explorer Reports | String Max Module Temp String Min Module Temp |
| String Non-operational Status [-] Available when data connection established | String | A string is marked non-operational if it sees less than 0.01 equivalent full cycles while peer strings see more than 0.01 on the same day. | Performance - Recoverable Energy System Monitor Reports | String Current |
| String RTE RTE [%] Available when data connection established | String | Round-trip efficiency of an individual string, calculated from energy throughput. | Data Explorer | String Current String Min Cell Voltage String Temp |
| Inverter RTE RTE [%] Available when data connection established | Inverter | Round-trip efficiency of the inverter, calculated from inverter-level signals and energy throughput. | Data Explorer | Inverter Active Power System Active Power AND Inverter Current DC Inverter Voltage DC OR Inverter Power DC |
| Transformer RTE RTE [%] Available when data connection established | Transformer | Round-trip efficiency of the transformer, based on energy throughput. | Data Explorer | Inverter Active Power System Active Power AND Inverter Current DC Inverter Voltage DC OR Inverter Power DC |
| System RTE RTE [%] Available when data connection established | System | System-wide round-trip efficiency, aggregating values from string, inverter, and transformer levels. | Warranty Data Explorer Reports | String Current String Voltage String Temperature Inverter Active Power System Active Power AND Inverter Current DC Inverter Voltage DC OR Inverter Power DC |
| String Availability Availability [%] Available when data connection established | String & System | Reflects component availability based on disconnected strings. | Warranty Data Explorer Reports | String Current |
| PCS Module Availability Availability [%] Available when data connection established | String & System | Reflects component availability based on disconnected PCS modules. | Warranty Data Explorer Reports | String voltage PCS module DC voltage |
| Guaranteed Power Availability Availability [%] Available when data connection established | PCS module, AC combiner & System | Compares the available power with the guaranteed power. | Warranty Data Explorer | Available charge & discharge power\ \on the respective level |
| Requested Power Availability Availability [%] Available when data connection established | PCS module, AC combiner & System | Compares the delivered power with the requested power. | Warranty Data Explorer | Requested power\ Active power\ \on the respective level |
| Missed Requested Energy Availability [MWh] Available when data connection established | PCS module, AC combiner & System | Compares the delivered power with the requested power and quantifies the missed Energy. | Warranty Data Explorer | Requested power\ Active power\ \on the respective level |
| Total Usable Energy Energy [MWh] Operational data needed (1-30 cycles) | System | Usable energy for daily operation, accounting for aging, recoverable energy, and missing data. | Performance - Recoverable Energy Data Explorer Reports | String Current String Voltage String Max Cell Voltage String Min Cell Voltage String Min/ Max Cell ID or Location String Temperature |
| Inverter Usable Energy Energy [MWh] Operational data needed (1-30 cycles) | Inverter | Usable energy from one inverter for daily operation, considering aging, recoverable energy, and missing data. | Performance - Recoverable Energy | String Current String Voltage String Max Cell Voltage String Min Cell Voltage String Min/ Max Cell ID or Location String Temperature |
| String Usable Energy Energy [kWh] Operational data needed (1-30 cycles) | String | Usable energy from a single string for daily operation, taking aging, imbalances, non-operation and weak cells into account. | Performance - Recoverable Energy | String Current String Voltage String Max Cell Voltage String Min Cell Voltage String Min/ Max Cell ID or Location String Temperature |
| Total Recoverable Energy Energy [MWh] Operational data needed (1-30 cycles) | System | Recoverable energy on system level due to non-operational components, weak cells or imbalances. | Performance - Recoverable Energy Reports | String Current String Voltage String Max Cell Voltage String Min Cell Voltage String Min/ Max Cell ID or Location String Temperature |
| Inverter Recoverable Energy Energy [MWh] Operational data needed (1-30 cycles) | Inverter | Recoverable energy on inverter level due to non-operational components, weak cells or imbalances. | Performance - Recoverable Energy Energy | String Current String Voltage String Max Cell Voltage String Min Cell Voltage String Min/ Max Cell ID or Location String Temperature |
| String Recoverable Energy Energy [kWh] Operational data needed (1-30 cycles) | String | Recoverable energy on string level due to non-operation, weak cells or imbalances. | Performance - Recoverable Energy | String Current String Voltage String Max Cell Voltage String Min Cell Voltage String Min/ Max Cell ID or Location String Temperature |
| Depth of Discharge (DoD) Percentage [%] Available when data connection established | String | The daily maximum difference between the maximum and minimum State of Charge | Warranty | BMS SoC TWAICE SoC |
| String Penalty Cycles (daily/ cumulative) Counter [-] Available when data connection established | String | Cycle count meeting defined penalty conditions as specified in warranty contract, tracked daily and cumulatively. | Warranty Data Explorer | String Current Warranty-specific inputs |
| String Warranty-relevant Cycles (daily/ cumulative) Counter [-] Available when data connection established | String | Cycle count including penalty cycles, tracked daily and cumulatively. | Warranty Data Explorer | String Current Warranty-specific inputs |
| Weak Cell Detection Boolean [-] Operational data needed (1-30 cycles) | String | Identification of individual cells which are limiting the string performance | Performance - Recoverable Energy | String Max Cell Voltage String Min Cell Voltage String Min/ Max Cell ID or Location |
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