{
 "id": "solar_cost_per_kw_retrofit_0_4kw",
 "name": "Solar PV installed cost on existing homes, 0 to 4 kW systems",
 "category": "costs",
 "value_num": 2108.65,
 "display": "£2,108.65/kW mean, existing homes only",
 "unit": "pounds per kW of total installed capacity (TIC), domestic retrofit installations only (existing homes, not new builds)",
 "period_start": "2025-04-01",
 "period_end": "2026-03-31",
 "period_kind": "data",
 "deadline": null,
 "source_url": "https://www.gov.uk/government/statistics/solar-pv-cost-data",
 "source_org": "DESNZ (from the MCS Installation Database)",
 "checked_at": "2026-09-08",
 "recheck_by": "2027-05-27",
 "history": [
  {
   "period": "2024/25",
   "value_num": 2109.54,
   "display": "£2,109.54/kW mean, existing homes only (56,493 installations)"
  }
 ],
 "public_note": "This is the figure for a house that already exists, which is the house most people reading this own. The government splits its home installations into existing homes and new builds, and new builds are fitted by developers at a lower rate per kW. Count the panels, the fitting and the grid connection, with VAT where any applies. No battery, no extended warranty. Almost exactly where it was the year before.",
 "next": null,
 "url": "https://hearthsum.co.uk/api/solar_cost_per_kw_retrofit_0_4kw.json"
}