Energy storage power supply grounding requirements and specifications

Why do battery energy storage systems need grounding and bonding?

For grid-scale battery energy storage systems (BESS), grounding and bonding is essential for safety and performance. The goal of grounding and bonding is to achieve customer-targeted resistance levels. These low resistance levels allow fault currents to easily discharge into the ground, protecting people, equipment and the BESS itself.

Why do I need a grounded system?

An effectively grounded system with respect to the Company’s EPS must be provided to ensure neutral stability, facilitate ground fault detection, and avoid distribution circuit over voltage during accidental isolation of the Company’s area EPS from the Company’s main system.

Should battery energy storage system (BESS) use GFM?

Studies conducted thus far indicate these numbers may be upwards of 30%.1,2,3 Since the current percentage of GFM resources is near zero in nearly all large, interconnected power systems, it is recommended to start requiring and enabling GFM in all future Battery Energy Storage System (BESS) projects for multiple reasons.

What are local power system requirements?

Local power system requirements may lead to operational power factors at the POI ranging between 0.9 lagging (VARs to the power system) and unity. These facilities will also be required to meet the latest Regional ISO, NPCC, or local regional planning criteria.

How long does a grounding system last?

High-quality, value-engineered grounding systems are key to meeting the desired BESS infrastructure service life of at least 25 years. Other solutions may meet these requirements initially but will degrade over time. nVent provides tested solutions that will deliver long-term consistent results.

Do der facilities need to be grounded?

To avoid overvoltage on the distribution EPS and other customers, the Company’s policy requires any DER facility 500 kW and above connected to a four-wire multi-grounded distribution feeder to provide an effectively grounded system with respect to the Company’s EPS. Refer to Section 7.1.4 for specific grounding requirements.