Tales of BESS #7 - Case Study: SOC discrepancy : 32MW / 32MWh (UK)

SOC discrepancy : 32MW / 32MWh (UK)

The BESS is operated by the Technical Asset Management team of Greensolver on the behalf of the Asset owner. The BESS is 32MW / 32MWh located in UK.

As part of the TAM scope of services, Greensolver team used on daily basis the Safety & Performance analytic tool BatteryInsight to ensure the SOC figures accuracy.

Wrong SOC figures given by the BMS and used by the RTM operator led to operational discrepancies and imbalances for the WM position and DFR services, which end by lost of revenues.

Thanks to the raw data: Temperature, Voltage and Current given by the SCADA/BMS at Battery racks level, Greensolver team was able to highlight SOC deviation between the SOC figures given by the BMS on site and the SOC figures calculated by BatteryInsight.

As part of the Performance feature of the tool, recurrent SOC deviation alarms was triggered, highlighting potential SOC calculation issue by the BMS from commissioning date. Below summary of the action plan managed by Greensolver team:

• First action: by tracking those alarms, Greensolver team could focus cause on the BMS
• Second action: Greensolver team requested remedial action to the Battery OEM
• Third action: Battery OEM performed a software update of the BMS to improve the SOC calculation

From the date of the software update, no more critical SOC deviation alarm have been raised. RTM operator gained in visibility to position the asset on the market applications reducing the risk of discrepancy.

Written by David Roissé