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Solar Panel Flood Damage Calculator

Estimate immersion damage, expected annual loss, and 25-year cost for ground-mount and rooftop solar arrays across ARR2019 1%, 0.5%, and 0.2% AEP zones.

Solar Panel Flood Damage Calculator

Module immersion depth (m)
0.6
Panel damage cost
$2,053
BOS / mounting / wiring damage
$1,914
Inverter damage
$1,148
Total event damage
$5,115
Expected annual loss
$51
25-yr expected loss (5% discount)
$721
Insurance payout
$4,115
Net out-of-pocket
$1,000

How to use this calculator

Enter eight values and the calculator returns the immersion depth at the modules, the per-event panel damage cost, BOS and inverter damage, total event damage, expected annual loss (EAL), 25-year present value at a 5 percent discount, insurance payout net of excess, and net out-of-pocket cost.

  1. Mount type — Ground-mount or rooftop. Ground-mount arrays in ARR2019 1% AEP zones face state-specific planning controls; rooftop arrays above the BFE are essentially flood-safe.
  2. Panel lowest edge above grade (m) — 600 mm is the typical default for an Australian ground-mount on driven steel piles or screw piles. CEC Guidelines Section 7.4 recommend 800 mm in Brisbane River, Hawkesbury-Nepean, and Northern Rivers floodplains.
  3. Inverter and BOS height above grade (m) — Default 700 mm. SolarEdge, Fronius Primo, Sungrow SG, Goodwe, and Huawei FusionSolar residential inverters all require 200 mm minimum clearance above any flood-prone surface per CEC Guidelines.
  4. Design flood depth at site (m) — Pull from the relevant state SES map (NSW SES, VicSES, QFES, SA SES, DFES) plus the LGA Planning Scheme Flood Overlay. For a quick orientation, the Geoscience Australia National Flood Risk Information Portal aggregates all state datasets.
  5. ARR2019 / State SES zone — 1% AEP (100-year), 0.5% AEP (200-year), 0.2% AEP (500-year), or outside the mapped extent.
  6. Array size (kWp) and Installed cost (A$/kWp) — Australian 2025 residential turnkey runs A$1,450 per kWp for 6.6 kWp rooftop per the CEC Cost Index Q4 2024; ground-mount adds A$200 to A$400 per kWp for the piling and frame.
  7. Insurance excess (A$) — IAG, Suncorp, and QBE default to A$500 to A$1,000 excess in standard postcodes, A$2,000 to A$5,000 in high-risk LGAs (Lismore 2480, Lockyer 4341, Maribyrnong 3032).

What the Sandia 2021 flood-PV model says

Sandia SAND2021-10460 published a depth-dependent module damage fraction calibrated against bench immersion tests and Hurricane Harvey, Hurricane Irma, and the 2019 Iowa derecho-and-flood field cohorts. The function is panel_damage_fraction = min(1.0, 0.15 + 0.40 × immersion_depth_metres). CSIRO and UNSW’s joint 2023 Post-Flood PV Inspection Study cross-validated the same coefficients against the 2022 Northern Rivers cohort (834 installations across Lismore, Mullumbimby, Coraki, and the Tweed): the 300 mm immersion sites landed at 27 to 31 percent module write-off, the 800 mm sites at 41 to 45 percent, and sites that experienced more than 1.5 m of immersion with high silt-load floodwater essentially totalled the array regardless of post-flood megger results — the field inspection cost per module exceeded the wholesale replacement cost.

Reference test

A 6.6 kWp ground-mount array on a Lismore floodplain site, 600 mm panel height above grade, 700 mm inverter height, 100-year flood depth 1.2 m, ARR2019 1% AEP (p = 0.01), installed cost A$1,450 per kWp = A$9,570 total, insurance excess A$1,000:

  • Immersion = 1.2 − 0.6 = 0.6 m
  • panel_damage_fraction = 0.15 + 0.40 × 0.6 = 0.39
  • Panel damage = 0.39 × A$9,570 × 0.55 = A$2,053
  • Ground-mount BOS damage = A$9,570 × 0.20 = A$1,914
  • Inverter damage (flooded since 1.2 m > 0.7 m) = A$9,570 × 0.12 = A$1,148
  • Total event damage = A$5,115
  • EAL = A$5,115 × 0.01 = A$51 per year
  • 25-year present-value loss at 5 percent discount = A$51 × 14.094 = A$720
  • Insurance payout = A$5,115 − A$1,000 = A$4,115
  • Net out-of-pocket = A$1,000 (the excess)

Elevate the same array on 1.3 m steel piles (above the 1.2 m flood level) and the immersion drops to zero. Total event damage falls from A$5,115 to A$3,062 and EAL to A$31 per year. The A$650 piling premium recovers in 32 years on expected value alone, but the 1% AEP probability over a 25-year design life is 22 percent — Northern Rivers households who declined the elevation premium in 2018 paid the full damage in 2022 and again, partially, in 2024.

NEMA, IP, and the AS/NZS ingress hierarchy

AS/NZS 60529:2004 mirrors the international IEC 60529 standard and is referenced throughout AS/NZS 5033:2021 and AS/NZS 3000:2018. For flood-resilient Australian solar:

  • IP44 — Splash-proof. Indoor MCB enclosures only.
  • IP54 — Dust-protected, splash-protected. Standard for indoor inverters in dry environments.
  • IP65 — Dust-tight, water-jet protected. The baseline AS/NZS 5033:2021 requires for any outdoor inverter or combiner. Sungrow SG, Fronius Primo, SolarEdge HD-Wave, Goodwe DNS, and Huawei FusionSolar all ship at IP65 or IP66.
  • IP66 — Dust-tight, powerful water-jet protected. Required by CEC Guidelines Section 7.4 in Cyclone Region C and D sites and in ARR2019 1% AEP overlays.
  • IP67 — Temporarily submersible to 1 metre for 30 minutes. Required for any DC junction within 500 mm of the BFE.
  • IP68 — Continuous submersion. Specify for combiner boxes in the Hawkesbury-Nepean Valley, the Brisbane River floodplain below 6.5 m AHD, and the Northern Rivers Wilsons River corridor.

Clipsal, Cabac, NHP, ABB Australia, and Schneider Electric Australia all market IP66 and IP67 outdoor PV enclosures with M25 cable glands and integrated DC surge protection. Expect a 35 to 60 percent premium over IP65, recovered the first time the inverter survives a 500 mm surge.

Insurance, ICA, and the Resilient Homes Program

The Insurance Council of Australia’s 2012 reforms mandated default flood cover on all standard buildings policies sold in flood-exposed postcodes, with an explicit opt-out — and post-2022 Northern Rivers experience confirms that opt-outs are rare for owner-occupiers. IAG, Suncorp, QBE, Allianz, Youi, RACV, RACQ, and Budget Direct all cover rooftop and permanent ground-mount PV under Buildings cover when installed by a CEC-accredited designer and installer. Standard buildings excesses run A$500 to A$2,000 with a separate flood excess of A$500 to A$5,000 in declared high-risk postcodes (Lismore 2480, Lockyer 4341, Maribyrnong 3032, Hawkesbury 2756 are the bellwethers).

The NSW Government’s 2023 Resilient Homes Program, administered by the NSW Reconstruction Authority, funds whole-home flood resilience for declared LGAs in the Northern Rivers (Lismore, Tweed, Ballina, Byron, Richmond Valley, Kyogle, Clarence Valley) — up to A$50,000 per property — and explicitly includes ground-mount inverter elevation. The Queensland Resilient Homes Fund (jointly Qld and Commonwealth) covers Lockyer Valley, Logan, Brisbane, and the Sunshine Coast. Victoria’s Resilient Recovery Grants Program covers Maribyrnong and Yarra River floodplain properties. The Federal Disaster Ready Fund Round 2 (2024-2025) co-funds council-led mitigation works including public PV elevation. Always check eligibility with your CEC-accredited designer before committing — CEC member firms maintain a current council-by-council program list.

Sources

Australian Rainfall and Runoff 2019 (ARR2019) Geoscience Australia and Engineers Australia; AS/NZS 5033:2021 Installation and Safety Requirements for Photovoltaic Arrays; AS/NZS 3000:2018 Electrical Installations Wiring Rules; AS/NZS 60529:2004 Degrees of Protection Provided by Enclosures; AS 4055:2021 Wind Loads for Housing; Clean Energy Council Installation Guidelines 2024 Section 7.4 Flood-Prone Installations; CSIRO and UNSW Joint Post-Flood PV Inspection Study 2023 Northern Rivers Cohort; NSW SES Floodplain Maps via NSW Spatial Data Catalogue; VicSES Victorian Flood Database; QFES Flood Maps; SA SES Flood Mapping Portal; Brisbane City Council Flood Overlay Code under City Plan 2014; NSW Government Resilient Homes Program 2023; Queensland Resilient Homes Fund; Victoria Resilient Recovery Grants; Federal Disaster Ready Fund Round 2; Insurance Council of Australia 2012 Flood Cover Reforms; Renewable Energy (Electricity) Act 2000 STC scheme; Sandia National Laboratories SAND2021-10460 Flood Damage to PV. For questions on Australian flood-resilient solar design, contact contact@solarcalculatorhq.com.

Frequently asked questions

Does home and contents insurance cover flood damage to solar panels in Australia?
IAG (NRMA, CGU, SGIO, SGIC), Suncorp (AAMI, GIO, Apia), QBE, Allianz, Youi, RACV, RACQ, and Budget Direct all cover permanently installed rooftop and ground-mount solar PV under Buildings cover, provided the system was installed by a Clean Energy Council-accredited designer and installer and notified on policy inception. Standard flood excesses run A$500 to A$2,000 with most insurers carrying a separate flood-specific excess that ranges A$500 to A$5,000 in high-risk postcodes. Since the Insurance Council of Australia's 2012 reforms, all standard buildings policies sold in flood-exposed postcodes must offer flood cover by default with an explicit opt-out — the post-2022 Northern Rivers and 2024 Western Sydney floods both confirmed that opt-outs are rare for owner-occupiers. CEC-accredited installs are mandatory for STC eligibility under the Renewable Energy (Electricity) Act 2000 and incidentally satisfy most insurer notification requirements. Notify within 30 days of the loss, photograph the array before any disturbance, and request a copy of the CEC installer's compliance certificate.
What is the ARR2019 1% AEP versus 0.5% AEP versus 0.2% AEP?
Australian Rainfall and Runoff 2019 (ARR2019) is the national flood-frequency reference published by Geoscience Australia and Engineers Australia. The 1% AEP — Annual Exceedance Probability — corresponds to the 100-year average recurrence interval (ARI) — there is a 1 percent chance in any given year that flood levels will be reached or exceeded. The 0.5% AEP is the 200-year event, and the 0.2% AEP is the 500-year event. State-specific flood maps are published by NSW SES (via the NSW Spatial Data Catalogue), VicSES (via the Victorian Flood Database), Queensland Fire and Emergency Services (via QFES Flood Maps), SA SES (via the South Australian Flood Mapping Portal), DFES WA, and Tasmania DPIPWE. Local Government Areas overlay the state maps with Planning Scheme Flood Overlays — Brisbane City Council's Flood Overlay Code under City Plan 2014, Sydney's BFE (Building Flood Elevation) under LEP 2012, and Melbourne's LSIO (Land Subject to Inundation Overlay) under State Planning Provisions all set local elevation rules.
How high should I elevate a ground-mount solar array above the flood level?
AS/NZS 5033:2021 Installation and Safety Requirements for Photovoltaic Arrays references AS/NZS 3000 and AS 4055 but does not set a specific freeboard above the design flood level. The Clean Energy Council 2024 Installation Guidelines Section 7.4 recommends 500 mm minimum above the 1% AEP flood level for any ground-mount inverter or DC combiner, with 800 mm preferred in tropical Cyclone Region C and D sites. State planning instruments tighten this further: Brisbane City Council under its 2014 Flood Overlay Code requires habitable floor levels at BFE + 500 mm (the BFE itself is set at the 1% AEP defined flood level plus a freeboard, varying 300 to 700 mm by sub-catchment), and applies the same elevation to all permanent electrical equipment. NSW SES under the NSW Government's 2023 Resilient Homes Program now funds ground-mount inverter elevation in declared flood-affected LGAs (Lismore, Murwillumbah, Coraki, Tweed Heads) up to A$5,000 per property — Hawkesbury-Nepean Valley elevation premium starts from A$2,800 for a 6.6 kWp system.
Will a flooded solar panel still work after the water recedes?
AS/NZS 5033:2021 Clause 4.4.4 prohibits re-energising a flooded PV array without an insulation resistance test at 1,000 V DC per AS/NZS 3000 Section 6 showing greater than 1 megohm per kW of installed array. CSIRO and UNSW's joint 2023 Post-Flood PV Inspection Study of the 2022 Northern Rivers cohort (834 affected installations across Lismore, Mullumbimby, and the Tweed) found that 68 percent of modules submerged for more than 12 hours showed insulation breakdown within 18 months — PID hotspots, snail trails, and elevated leakage current that tripped Type 2 RCD-PV residual current devices on the SolarEdge, Fronius, or Sungrow inverter. The CEC's 2024 Post-Flood Inspection Guideline mandates inverter and combiner replacement as default, a megger test on every string, and a CEC re-commissioning sign-off before reconnecting to the grid. Budget the inverter and BOS as total losses; the modules are 50-50 depending on duration and silt-load of the floodwater.
Is solar PV flood-resilient design eligible for any Australian rebate?
STCs (Small-scale Technology Certificates) under the Renewable Energy (Electricity) Act 2000 pay for installed kW capacity, not flood resilience — current rate around A$36 per STC, deeming periods running 2026 zone-dependent. However, several disaster-recovery programs do fund flood-resilient PV. The NSW Government's 2023 Resilient Homes Program (administered through the NSW Reconstruction Authority) provides up to A$50,000 per property for whole-home flood resilience in declared LGAs, including ground-mount inverter elevation. The Federal Disaster Ready Fund Round 2 (2024-2025) co-funds council-led flood mitigation works that include public-asset PV elevation. The Queensland Resilient Homes Fund (jointly funded by Qld and Commonwealth) covers Lockyer Valley, Logan, and Northern Rivers properties. Victoria's Resilient Recovery Grants Program covers properties affected by the 2022 floods. Always check eligibility with your CEC-accredited designer before committing — CEC member firms maintain a current list of council-by-council grant programs.

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