{
  "node": {
    "id": "term:ul-1741",
    "type": "Term",
    "label": "UL 1741",
    "properties": {
      "id": "ul-1741",
      "name": "UL 1741",
      "aka": [
        "UL 1741 SB",
        "UL 1741 SA"
      ],
      "section": "topic-standards-stationary",
      "definition": "The North American safety standard for inverters, converters, charge controllers and interconnection equipment used with distributed energy resources such as solar and battery storage. Its Supplement SB certifies grid-support functions, such as ride-through and voltage and frequency response, against the tests of IEEE 1547.1-2020, taking over from the earlier Supplement SA.",
      "related": [
        "inverter",
        "ul-9540",
        "stationary-storage",
        "frequency-regulation",
        "vehicle-to-grid"
      ],
      "url": "https://lemonergy.com/learn/glossary/ul-1741/",
      "mentions": []
    }
  },
  "edges": [
    {
      "id": "edge:6447",
      "source": "term:ul-1741",
      "target": "topic:topic-standards-stationary",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:6448",
      "source": "term:ul-1741",
      "target": "term:inverter",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6449",
      "source": "term:ul-1741",
      "target": "term:ul-9540",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6450",
      "source": "term:ul-1741",
      "target": "term:stationary-storage",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6451",
      "source": "term:ul-1741",
      "target": "term:frequency-regulation",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6452",
      "source": "term:ul-1741",
      "target": "term:vehicle-to-grid",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6453",
      "source": "term:ul-1741",
      "target": "reference:ul-storage",
      "type": "cites",
      "properties": {
        "sourceFile": "wiki-references.json",
        "scope": "direct technical reference"
      }
    }
  ],
  "neighbors": [
    {
      "id": "topic:topic-standards-stationary",
      "type": "Topic",
      "label": "Stationary, industrial and product standards",
      "properties": {
        "id": "topic-standards-stationary",
        "name": "Stationary, industrial and product standards",
        "lede": "Safety and performance standards for portable, industrial and grid batteries, their electronics and their installation.",
        "context": "Match scope to product and installation.",
        "example": "A cell-level test does not establish fire performance or commissioning requirements for a complete installation.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/battery-basics/",
        "lesson_label": "Open battery basics"
      }
    },
    {
      "id": "term:inverter",
      "type": "Term",
      "label": "Inverter",
      "properties": {
        "id": "inverter",
        "name": "Inverter",
        "aka": [
          "power conversion system",
          "PCS"
        ],
        "section": "topic-pack",
        "definition": "The power electronics that turn the battery’s DC into AC for a motor or the grid, and back again for charging. In stationary storage it is called the power conversion system and its rating in kW or MW sets the system’s power independently of the battery’s energy.",
        "related": [
          "pre-charge",
          "dc-dc-converter",
          "stationary-storage",
          "energy-management-system",
          "direct-current",
          "iec-62477-1"
        ],
        "url": "https://lemonergy.com/learn/glossary/inverter/",
        "mentions": []
      }
    },
    {
      "id": "term:ul-9540",
      "type": "Term",
      "label": "UL 9540",
      "properties": {
        "id": "ul-9540",
        "name": "UL 9540",
        "section": "topic-standards-stationary",
        "definition": "The North American product safety standard for a complete energy storage system — battery, inverter and controls together — as opposed to UL 9540A, which is the test method for its thermal-runaway behaviour. Listing to UL 9540 is what most US fire codes require for installation.",
        "related": [
          "ul-9540a",
          "nfpa-855",
          "stationary-storage",
          "inverter",
          "pas-63100"
        ],
        "url": "https://lemonergy.com/learn/glossary/ul-9540/",
        "mentions": []
      }
    },
    {
      "id": "term:stationary-storage",
      "type": "Term",
      "label": "Stationary storage",
      "properties": {
        "id": "stationary-storage",
        "name": "Stationary storage",
        "abbr": "BESS",
        "aka": [
          "battery energy storage system",
          "ESS"
        ],
        "section": "topic-applications",
        "definition": "Batteries installed in a fixed place — a container at a solar farm, a cabinet in a home — to shift energy in time or support the grid. LFP cells dominate because cost per cycle and safety matter more than mass.",
        "related": [
          "lfp",
          "energy-management-system",
          "inverter",
          "energy-arbitrage",
          "long-duration-storage",
          "ul-9540a"
        ],
        "url": "https://lemonergy.com/learn/glossary/stationary-storage/",
        "mentions": []
      }
    },
    {
      "id": "term:frequency-regulation",
      "type": "Term",
      "label": "Frequency regulation",
      "properties": {
        "id": "frequency-regulation",
        "name": "Frequency regulation",
        "aka": [
          "ancillary services",
          "frequency response"
        ],
        "section": "topic-applications",
        "definition": "Rapidly injecting or absorbing power to hold the grid frequency at 50 or 60 Hz, a service batteries do better than any generator because they respond in milliseconds. It cycles the battery shallowly but very often.",
        "related": [
          "stationary-storage",
          "energy-arbitrage",
          "specific-power",
          "equivalent-full-cycle",
          "rate-of-change-of-frequency"
        ],
        "url": "https://lemonergy.com/learn/glossary/frequency-regulation/",
        "mentions": []
      }
    },
    {
      "id": "term:vehicle-to-grid",
      "type": "Term",
      "label": "Vehicle-to-grid",
      "properties": {
        "id": "vehicle-to-grid",
        "name": "Vehicle-to-grid",
        "abbr": "V2G",
        "aka": [
          "V2L",
          "V2H",
          "bidirectional charging"
        ],
        "section": "topic-infrastructure",
        "definition": "Discharging a vehicle’s battery back into a house or the grid through a bidirectional charger, so parked cars act as storage. Vehicle-to-load and vehicle-to-home are the simpler forms that power appliances or a house directly.",
        "related": [
          "electric-vehicle",
          "stationary-storage",
          "energy-arbitrage",
          "cycle-aging"
        ],
        "url": "https://lemonergy.com/learn/glossary/vehicle-to-grid/",
        "mentions": [
          "charger"
        ]
      }
    },
    {
      "id": "reference:ul-storage",
      "type": "Reference",
      "label": "Energy Storage System Testing and Certification",
      "properties": {
        "title": "Energy Storage System Testing and Certification",
        "publisher": "UL Solutions",
        "url": "https://www.ul.com/services/energy-storage-system-testing-and-certification",
        "type": "Official documentation",
        "scope": "System safety scope of UL 9540 and relationships to battery and power-conversion standards.",
        "accessed": "2026-10-27"
      }
    }
  ]
}