Energy Storage Systems (ESS) Plan Review & Inspection

At Texas Power Inspections (TPI), we provide complete combined plan review and inspection services for residential energy storage systems (ESS) across Texas. Our process ensures every battery installation complies with SB 1202, NEC Article 706, IRC R330, and UL 9540/9540A standards — giving contractors and homeowners confidence that their systems are safe, compliant, and ready for long-term performance.

We work directly with contractors and AHJs to verify that each system meets electrical safety, structural, ventilation, and fire protection requirements, as adopted by local jurisdictions throughout Texas.

What We Review

TPI’s plan review process examines all design documentation, electrical diagrams, and manufacturer data to ensure full compliance before installation begins.

During plan review, we verify the following:

  • Scaled site plan: Shows battery location (interior/exterior), clearances from walls and openings, disconnect locations, inverters, service panels, and transfer switches.

  • System documentation: Review of all manufacturer data sheets for batteries, inverters, transfer switches, and controllers — confirming each is listed by a Nationally Recognized Testing Laboratory (NRTL) such as UL, Intertek, or CSA.

  • Battery listing verification: Confirm each ESS unit is UL 9540 certified and, where required, tested to UL 9540A standards for thermal runaway performance

  • System capacity and limits: Ensure compliance with IRC R330.5 energy limits — no more than 20 kWh per unit, and aggregate capacity not exceeding:

    • 40 kWh inside closets, basements, or utility rooms

    • 80 kWh in attached/detached garages or accessory structures

    • 80 kWh outdoors (wall-mounted or ground-mounted)

  • Electrical design: Verify conductor sizes, insulation types, disconnect ratings, overcurrent protection, grounding and bonding per NEC 706.20–706.31.

  • One-line diagram: Confirm accuracy of conduit routing, wire sizes, breaker ratings, and labeling for AC/DC disconnects, inverters, and service panels.

  • Ventilation and environment: Review manufacturer requirements and site conditions to confirm adequate air exchange, temperature control, and separation from ignition sources.

  • Fire and clearance spacing: Confirm compliance with IRC R330, including minimum clearance from doors, windows, and property lines.

  • Signage and labeling: Verify proposed labeling per NEC 706.15 and manufacturer instructions, including “Energy Storage System” and disconnect identification.

  • Interconnection coordination: Review integration with solar or generator systems to confirm safe load management and correct utility tie-in configuration (supply-side or load-side).

What We Inspect

After plan approval, TPI conducts a detailed inspection to confirm that the installation matches the approved design and all safety standards are met.

During inspection, we verify:

  • Battery installation and mounting: Proper anchoring, spacing, and environmental protection per manufacturer specifications.

  • Disconnects and overcurrent devices: Correct placement, labeling, and accessibility.

  • Conduit and wiring: Proper size, routing, and protection from physical damage.

  • Grounding and bonding: Continuity and compliance with NEC 250 and 706.30.

  • Clearances and ventilation: Minimum spacing from combustible materials and openings, and compliance with environmental and temperature ratings.

  • System labeling: Permanent and legible markings identifying voltage, hazard, and emergency contact information.

  • Commissioning verification: Safe startup and operational testing under manufacturer guidelines.

  • Fire safety compliance: Separation from habitable spaces, and confirmation of location requirements under IRC R330.5–R330.8 and IFC 1207.

  • Interconnection safety: Confirm that system interfaces with solar or generator equipment function properly without overloading service equipment or violating NEC 705.

Important Notice: The inspection and review items listed above are intended to serve as a general guideline and do not represent a complete list of all code, safety, or installation requirements. Additional elements may be included, excluded, or modified based on specific project conditions, system design, or field observations. All code references cited are based on the State of Texas’ currently adopted editions of the National Electrical Code (NEC), International Residential Code (IRC), International Fire Code (IFC), and International Building Code (IBC). Local Authorities Having Jurisdiction (AHJs) may adopt different code editions or amendments that can alter applicable requirements. It is the responsibility of the contractor or system owner to confirm compliance with the locally adopted codes and standards in effect at the time of project submission.