Engineering Resilience: How to Specify Medium Voltage Switchgear for Energy Storage

Technical Deep Dive: How to Specify Medium Voltage Switchgear for Energy Storage Systems

As energy storage projects scale in size and complexity, the demands placed on medium voltage (MV) switchgear are growing too. In Part 1, we explored the top features to look for in a high-performing system. Now, let's take a closer, more technical look at what it takes to specify switchgear that meets the real-world demands of modern energy storage projects.

Choosing the right switchgear is not just about ticking boxes — it's about engineering resilience, safety, and future flexibility into your project from day one.

1. Voltage Ratings and Standards Compliance

Energy storage switchgear must be carefully matched to the system's voltage class and meet rigorous industry standards.

• Common MV Classes: 5 kV, 15 kV, 27 kV, and 38 kV rated systems

• Primary Standards to Reference: ANSI/IEEE C37.20.2 (metal-clad switchgear design and testing), ANSI C37.55 (conformance testing for metal-clad switchgear), and ANSI/IEEE C37.20.7 (arc-resistant switchgear standards)

  
  

Ensure the gear is type-tested for withstand ratings, insulation coordination, and short-circuit performance appropriate to your interconnection voltage.

At GreenPowr, all MV switchgear designs meet or exceed applicable ANSI/IEEE and UL standards for energy storage and renewable integration.

2. Short-Circuit Ratings and Withstand Capability

With battery systems, the available fault current can be massive and fast-acting. Your switchgear must handle it.

• Momentary Withstand Ratings: Typically 25 kA to 63 kA for 2-3 seconds

• Interrupting Ratings: Matched to breakers; typical 25 kA, 31.5 kA, or 40 kA

  
  

Don't assume—always verify calculated maximum fault currents against the switchgear's rated short-circuit withstand and interrupting ratings.

3. Arc Flash Mitigation Strategies

Energy storage facilities are dense with equipment, and arc flash risks must be proactively managed.

Best practices include:

• Arc-resistant switchgear designs (tested to IEEE C37.20.7 Type 2B)

• Remote racking systems for circuit breakers

• Relaying and fast fault-clearing schemes to minimize incident energy

GreenPowr prioritizes arc flash risk reduction by integrating barrier systems, intelligent relaying schemes (differential protection, and light sensors) , and personnel protection features.

4. Smart Protection and Communication

Modern BESS installations demand switchgear that isn't "dumb" steel cabinets — they must integrate seamlessly into SCADA, EMS, and microgrid controllers.

Key features include:

• Advanced protective relays with programmable logic (SEL, ABB, Siemens)

• Communication protocols like Modbus, DNP3, or IEC 61850

• Remote monitoring of breaker positions, temperatures, and partial discharges

Switchgear should be ready for real-time fault isolation, load shedding, and dynamic grid support applications.

5. Modular Designs and Site Flexibility

Each project site is unique. Switchgear must adapt, not dictate.

Look for:

• Front-access or rear-access options

• Outdoor NEMA 3R enclosures

• Expandable lineups to add future ESS or PV blocks

  
  

GreenPowr’s modular switchgear approach helps projects scale efficiently without major redesigns or footprint expansions.

Engineering the Foundation for Success

Specifying MV switchgear for energy storage isn't about picking something "off the shelf." It's about future-proofing performance, protecting people and assets, and accelerating project timelines.

At GreenPowr, we believe great switchgear should quietly power great projects — built with American quality, engineered for flexibility, and designed to keep our clean energy future moving.