{
  "slug": "solar-soiling",
  "title": "Rain, Dust and Soiling: The Cleaning Your Climate Does For Free",
  "url": "https://solaranalytica.com/solar-soiling",
  "summary": "The energy a dirty panel loses spans two orders of magnitude across 40 markets: 1.5% a year in rain-washed Berlin, 5% in Perth, a 20% lower bound in the Gulf. The deciding variable is not how much dust falls but how often rain above a few millimetres follows it, and 17 markets carry honest blanks where no credible study exists.",
  "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/solar-soiling/data.csv",
  "datePublished": "2026-05-14",
  "lastReviewed": "2026-05-14",
  "sources": [
    {
      "title": "NREL: PV soiling review and regional soiling stations (fy22osti/83486)",
      "url": "https://docs.nrel.gov/docs/fy22osti/83486.pdf"
    },
    {
      "title": "IEA PVPS Task 13: Soiling losses of PV plants (2022)",
      "url": "https://iea-pvps.org/wp-content/uploads/2023/01/IEA-PVPS-T13-21-2022-REPORT-Soiling-Losses-PV-Plants.pdf"
    },
    {
      "title": "Kimber soiling model, Sandia PV Performance Modeling Collaborative",
      "url": "https://pvpmc.sandia.gov/modeling-guide/1-weather-design-inputs/shading-soiling-and-reflection-losses/soiling-losses/kimber-soiling-model/"
    },
    {
      "title": "Cordero et al.: Soiling across the Atacama transect (Scientific Reports 2018)",
      "url": "https://www.nature.com/articles/s41598-018-32291-8"
    },
    {
      "title": "DLR / Renewable Energy: Europe-wide PV soiling assessment (2005-2019)",
      "url": "https://elib.dlr.de/207307/1/4AO.9_2.pdf"
    },
    {
      "title": "Coello and Boyle: global soiling model (Applied Energy 2021)",
      "url": "https://www.sciencedirect.com/science/article/abs/pii/S0306261921000039"
    },
    {
      "title": "Ilse et al.: Techno-economic assessment of soiling (Joule)",
      "url": "https://elib.dlr.de/129424/1/Joule-ils.pdf"
    },
    {
      "title": "CSIRO: Solar photovoltaics, optimising performance",
      "url": "https://research.csiro.au/infratech/wp-content/uploads/sites/38/2024/12/4393_SolarPhotovoltaicsoptimisingperformance_WCAG.pdf"
    }
  ],
  "figures": [
    {
      "id": "annual-soiling-loss",
      "title": "Annual soiling loss with no cleaning, selected markets",
      "unit": "%",
      "caption": "Annual energy loss with no manual cleaning. Abu Dhabi and Riyadh are the NREL Middle East lower bound (20%+); Atacama is the Iquique transect point. Sources per market in the table below.",
      "series": [
        {
          "label": "Abu Dhabi",
          "value": 20
        },
        {
          "label": "Riyadh",
          "value": 20
        },
        {
          "label": "Atacama coast",
          "value": 18
        },
        {
          "label": "Jakarta",
          "value": 8
        },
        {
          "label": "Santiago",
          "value": 7
        },
        {
          "label": "Dubai",
          "value": 6
        },
        {
          "label": "Perth",
          "value": 5
        },
        {
          "label": "Phoenix",
          "value": 3
        },
        {
          "label": "Shanghai",
          "value": 1.7
        },
        {
          "label": "Berlin",
          "value": 1.5
        }
      ]
    },
    {
      "id": "dry-period-soiling-rate",
      "title": "Dry-period soiling rate, % of yield per day",
      "unit": "%",
      "caption": "Dry-period soiling rate, % of yield per day. Two orders of magnitude separate the Sahel and the wet tropics; Bamako is a West African savanna proxy, stated as such in the data.",
      "series": [
        {
          "label": "Bamako (Sahel)",
          "value": 0.7
        },
        {
          "label": "Abu Dhabi",
          "value": 0.6
        },
        {
          "label": "Santiago",
          "value": 0.6
        },
        {
          "label": "Cairo",
          "value": 0.5
        },
        {
          "label": "Jodhpur",
          "value": 0.44
        },
        {
          "label": "Atacama coast",
          "value": 0.31
        },
        {
          "label": "Phoenix",
          "value": 0.25
        },
        {
          "label": "Madrid",
          "value": 0.16
        },
        {
          "label": "Singapore",
          "value": 0.06
        },
        {
          "label": "Bogota",
          "value": 0.05
        }
      ]
    }
  ]
}