Battery storage
AC interface metering
Import and export energy measured at the AC side of your battery storage system, at the PCS or the grid connection. A clear record of what went in, what came out and when.
THE PROBLEM
What the battery says and what the site sees can differ
A battery energy storage system reports plenty about itself: state of charge, cell temperatures, DC power. But the owner's business case is written in AC kWh: energy bought from the grid or solar, energy delivered back to the site, and the losses in between.
Round-trip efficiency, peak shaving results and arbitrage revenue all depend on an independent AC measurement at the right point. Where several PCS units share one grid connection, each needs its own measurement as well.
Commercial and industrial sites also run storage alongside solar and generators, so the AC metering has to fit an electrical system with energy flowing in both directions.
HOW WE SET IT UP
Bidirectional AC data at the right points
Meter at the designated AC points
We place AC sub-meters at the PCS output and, where needed, at the storage grid connection. The points are agreed from the single-line diagram with the system integrator.
Import and export kept separate
Charge and discharge energy are recorded as separate registers where the meter supports them, so round-trip efficiency is a straight calculation over any period.
Battery data through Modbus
Battery management systems and PCS controllers often expose state of charge, alarms and DC values over Modbus. Our gateway reads them so AC and battery data sit on one timeline.
Dispatch and savings reports
With site load and solar metered as well, RIOD Live shows when the battery charged, when it discharged and what that did to the site peak.
AT A GLANCE
Battery storage metering at a glance
- Measured
- AC import and export energy where supported, AC power at the PCS or grid connection
- Hardware
- Smart energy sub-meters on the AC side; RS485 Modbus IoT gateway for BMS and PCS registers
- Connectivity
- Ethernet or 4G, Modbus RTU or TCP into the gateway
- Security
- MQTT over TLS 1.2 from every device
- Data goes to
- RIOD Live cloud, or the platform deployed on your own server
- Reports
- Audit trails on every report, PDF and Excel export, AI access to the data through MCP
- Engineering note
- DC battery telemetry comes from the BMS or dedicated DC hardware, read alongside the AC meters
FAQ
Questions buyers ask us
How do you measure the round-trip efficiency of a battery storage system?
Record AC energy into the system during charging and AC energy out during discharge at the same metering point, over a period long enough to start and end at a similar state of charge. Energy out divided by energy in gives round-trip efficiency including PCS losses.
Where should a BESS energy meter be placed?
At the AC terminals of each PCS for unit-level data, and at the storage system point of connection for the combined figure. The exact points come from the single-line diagram and the reporting you need.
Can you also monitor battery cell data?
Yes, through the battery management system. Cell voltages, temperatures and state of charge come from the BMS, and where it exposes them over Modbus our gateway reads them alongside the AC meters.
Can storage data be combined with solar and site load?
Yes. With solar output and the site incomer metered, reports show how the battery shifted solar energy and reduced peak demand.
Commissioning or operating battery storage?
Share the single-line diagram and the PCS and BMS models. We will propose the AC metering points and the data integration.