{
  "slug": "swis-rooftop-solar-atlas-2026",
  "title": "SWIS Rooftop Solar Atlas, 2026",
  "url": "https://solaranalytica.com/swis-rooftop-solar-atlas-2026",
  "summary": "A reference edition for 246 local Western Australian energy markets: rooftop solar and battery adoption, household addressability, published network opportunities, and the operating record of an isolated grid. It makes one point plainly: SWIS is not one market.",
  "license": "Free to use with attribution to Solar Analytica (solaranalytica.com). Underlying figures are named to their public sources below.",
  "csv": "https://solaranalytica.com/reports/swis-rooftop-solar-atlas-2026/data.csv",
  "datePublished": "2026-07-19",
  "lastReviewed": "2026-07-20",
  "sources": [
    {
      "title": "Clean Energy Regulator: small-scale installation postcode data",
      "url": "https://cer.gov.au/markets/reports-and-data/small-scale-installation-postcode-data"
    },
    {
      "title": "Australian Bureau of Statistics: Regional Population",
      "url": "https://data.api.abs.gov.au/rest/data/ABS,ABS_ANNUAL_ERP_ASGS2021,1.2.0/all?startPeriod=2011&format=csvfile"
    },
    {
      "title": "Australian Bureau of Statistics: Regional Population methodology and revision status",
      "url": "https://www.abs.gov.au/methodologies/regional-population-methodology/2024-25"
    },
    {
      "title": "Australian Bureau of Statistics: 2021 Census community profiles",
      "url": "https://www.abs.gov.au/census/find-census-data/community-profiles"
    },
    {
      "title": "Western Power: Network Opportunity Map",
      "url": "https://www.westernpower.com.au/resources-education/suppliers/tenders-and-registrations-of-interest/transmission-system-plan--network-opportunity-map/"
    },
    {
      "title": "AEMO WEM data service",
      "url": "https://data.wa.aemo.com.au/"
    }
  ],
  "figures": [
    {
      "id": "annual-solar-installation-flow",
      "title": "Annual allocated small-scale solar installation records, SWIS screening cohort",
      "unit": "thousand allocated installation records",
      "valueLabel": "Earlier recorded cohort",
      "valueBLabel": "Most recent recorded cohort",
      "caption": "Recorded small-scale solar installations in the public-extent screening cohort: 33,498 in the earlier 12-month window and 31,021 in the most recent window ending May 2026. This is not a like-for-like demand comparison: STCs may be created up to 12 months after installation, so recent counts continue to mature. CER postcode records are allocated fractionally to SA2s using ABS 2021 Postal Area to SA2 residential Mesh Block shares.",
      "series": [
        {
          "label": "CER allocation cohort",
          "value": 33.498,
          "valueB": 31.021
        }
      ]
    },
    {
      "id": "population-growth",
      "title": "Population of the SWIS public-extent screening cohort, 2011 and 2025",
      "unit": "million people",
      "valueLabel": "2011",
      "valueBLabel": "2025",
      "caption": "Estimated resident population across the 246-area public-extent screening cohort, 2011 and 2025. ABS classifies 2025 as preliminary, 2022-2024 as revised, and 2001-2021 as final. The cohort grew 31.0% over the period. This is an analytical boundary, not a licensed Western Power service territory.",
      "series": [
        {
          "label": "SWIS screening cohort",
          "value": 2.213463,
          "valueB": 2.900474
        }
      ]
    },
    {
      "id": "rooftop-pv-peak-share",
      "title": "Rooftop PV share at daily peak, retained AEMO WEM record",
      "unit": "percent of implied underlying demand",
      "valueLabel": "Average daily peak share",
      "valueBLabel": "Maximum daily peak share",
      "caption": "Rooftop PV at its daily peak as a share of the implied underlying-demand proxy across 1,019 retained AEMO WEM operating days, 2 October 2023 to 17 July 2026. The underlying-demand proxy is not a settlement-demand measure.",
      "series": [
        {
          "label": "AEMO WEM daily record",
          "value": 52.4036,
          "valueB": 80.8288
        }
      ]
    },
    {
      "id": "reference-edition-metrics",
      "title": "SWIS Rooftop Solar Atlas reference metrics, edition 01",
      "caption": "Fixed source-version metrics for reference edition 01. CER and ABS spatial measures use the public-extent screening cohort; operating metrics use the retained AEMO WEM record through 17 July 2026.",
      "series": [
        {
          "label": "Spatial cohort",
          "value": 246,
          "unit": "SA2s"
        },
        {
          "label": "Allocated solar installation records",
          "value": 564139,
          "unit": "records"
        },
        {
          "label": "Allocated solar capacity",
          "value": 3167.32608,
          "unit": "MW"
        },
        {
          "label": "Allocated battery installation records",
          "value": 43150,
          "unit": "records"
        },
        {
          "label": "Allocated battery capacity",
          "value": 933.63669,
          "unit": "MWh"
        },
        {
          "label": "Published network opportunities",
          "value": 15,
          "unit": "records"
        },
        {
          "label": "Operating days",
          "value": 1019,
          "unit": "days"
        },
        {
          "label": "Average rooftop PV share at daily peak",
          "value": 52.4036,
          "unit": "%"
        },
        {
          "label": "Maximum rooftop PV share at daily peak",
          "value": 80.8288,
          "unit": "%"
        },
        {
          "label": "Largest evening ramp",
          "value": 2411.729,
          "unit": "MW"
        },
        {
          "label": "Minimum operational demand",
          "value": 504.3312,
          "unit": "MW"
        }
      ]
    }
  ]
}