{
 "id": "mcs_kk_zone_1_london",
 "name": "MCS annual output per kWp, zone 1 (London)",
 "category": "payback",
 "value_num": [
  828,
  985
 ],
 "display": "828 to 985 kWh per kWp a year",
 "unit": "kWh per kWp of panels, from a flat roof (the table's orientation-free figure) to the table's best cell (south-facing at 37 to 39 degrees), before any shading",
 "period_start": "2025-02-26",
 "period_end": null,
 "period_kind": "page_date",
 "deadline": null,
 "source_url": "https://mcscertified.com/wp-content/uploads/2025/02/Irradiance-Datasets.xlsx",
 "source_org": "MCS",
 "checked_at": "2026-09-08",
 "recheck_by": "2027-03-08",
 "history": [],
 "public_note": "The flat-roof figure needs no guess about which way the roof faces. The top figure is the best cell in MCS's table for this zone. A real pitched roof facing south sits near the top, one facing east or west sits lower, and MCS's table gives every step between.",
 "next": null,
 "url": "https://hearthsum.co.uk/api/mcs_kk_zone_1_london.json"
}