{
  "$schema": "https://ps-wiki.github.io/schema/v1/term.schema.json",
  "id": "ancillary-services",
  "title": "Ancillary Services",
  "description": "Services necessary to support the transmission of electric power.",
  "language": "en",
  "tags": [
    "transmission",
    "reliability",
    "ferc",
    "nerc"
  ],
  "related": [],
  "breaking": false,
  "dates": {
    "created": "2025-03-15",
    "last_modified": "2025-06-20"
  },
  "authors": [
    {
      "name": "Jinning Wang",
      "url": "https://jinningwang.github.io"
    }
  ],
  "content": {
    "sections": [
      {
        "order": 1,
        "id": "definition-by-ferc",
        "title": "Definition by FERC",
        "type": "definition",
        "source_keys": [
          "ferc2020glossary"
        ],
        "page": null,
        "body_md": "> Those services necessary to support the transmission of electric power from seller to purchaser, given the obligations of control areas and transmitting utilities within those control areas, to maintain reliable operations of the interconnected transmission system. Ancillary services supplied with generation include load following, reactive power-voltage regulation, system protective services, loss compensation service, system control, load dispatch services, and energy imbalance services.\n\nMore details can be found in the Reference <d-cite key=\"nerc2011ancillary\"></d-cite> Appendix I: Regional Practices for Ancillary Services.\n"
      }
    ]
  }
}