{
  "assumptions": [],
  "data_window": {
    "daily_prices": [
      "2021-01-01",
      "2026-08-29"
    ],
    "detailed_intervals": [
      "2025-10-01",
      "2026-08-29"
    ],
    "long_history": [
      "2015-01-01",
      "2026-08-29"
    ]
  },
  "disclosure": "Analysis and drafting were model-assisted; sources, code, assumptions, and evidence hashes are disclosed.",
  "figure": {
    "alt": "Chart for Are negative electricity prices always low-carbon?: negative-price days at or above the sample median low-carbon share, shown as below median, at/above median.",
    "height": 675,
    "labels": [
      "below median",
      "at/above median"
    ],
    "url": "/research-media/home-papers/are-negative-electricity-prices-always-low-carbon.webp",
    "values": [
      38.42584329823309,
      61.57415670176691
    ],
    "width": 1200
  },
  "licence": "See /legal/data-licensing and docs/voltcast/LICENSING.md",
  "limitations": [
    "Low-carbon share is an operational generation proxy, not lifecycle emissions."
  ],
  "method_family": "episode survival, matched calendar controls, reliability scoring, and network lead-lag analysis",
  "multiplicity": "Within-family Holm control applies to inferential claims; this descriptive result makes no unadjusted significance claim.",
  "paper_id": "VOLT-HOME-WP-017",
  "primary_result": {
    "bootstrap_95_interval": null,
    "interpretation": "Negative wholesale prices often coincide with abundant low-marginal-cost output, but are not themselves a carbon measure.",
    "interval_method": "not reported for this estimand",
    "metric": "negative-price days at or above the sample median low-carbon share",
    "sample_size": 5603,
    "unit": "%",
    "value": 61.57415670176691
  },
  "provenance": {
    "analysis_code_sha256": "57c57de79cdab2b5b6d6c54c485cb5162598c5ba0b0bfe995da40d75e6c52ba9",
    "protocol_sha256": "adb36bf6b447af9f96339249b8becaefc20422499cca1977242866347a97bd4b",
    "read_only_transaction": true,
    "registry_sha256": "7bcb91d7476d0a69fe9fa75a5c7782f8117e0153f82f9112b7e1d307d3943717",
    "snapshot_sha256": "f77e3ae328f93916e53b1bab7516e1d0ac740a0dbf424cd2b73c81fee2559318",
    "source_registry_sha256": "07949550ac443ff673fda5c0209b99f137544f3ffecf6775f109bb9d09663bd6",
    "statement_timeout_seconds": 180
  },
  "publication_cutoff": "2026-08-30T00:00:00Z",
  "schema": "volt-home-paper-evidence-v1",
  "secondary_results": [],
  "series": "home-energy-working-papers-v1",
  "slug": "are-negative-electricity-prices-always-low-carbon",
  "source_tables": [
    "day_ahead_prices",
    "generation_mix",
    "border_flows",
    "risk_accuracy",
    "zone_holidays"
  ],
  "status": "measured",
  "title": "Are negative electricity prices always low-carbon?"
}