Solar panels and storms in Perth: what's safe, what's at risk, and what to do after

Perth's weather is predominantly solar-friendly, but summer thunderstorms, fremantle doctors, and the occasional severe storm event create legitimate questions for solar owners. Here's how modern systems handle WA weather — and what to check when weather events cause concern.

Do you need to shut down solar during storms?

For most storms: no. Modern grid-connected solar inverters automatically disconnect from the grid if grid voltage or frequency exceeds normal limits — which happens during outages, grid disturbances, and major weather events. This disconnection is a safety function built into Australian-compliant inverters under AS/NZS 4777.

When you should manually switch off:

• If Western Power notifies you of a planned outage and asks you to switch off your solar system (they sometimes do for major maintenance work)
• If your property is directly at risk of flooding and there's water near the switchboard
• If you observe physical damage to panels, inverters, or wiring during or after a storm
• If your inverter shows a fault after a lightning event nearby

How to switch off the solar system:

1. Turn off the AC solar isolator at the switchboard (labelled "Solar Main Switch" or similar)
2. Turn off the DC isolator at the inverter (a red switch, typically labelled "Array DC Isolator")
3. Turn off the DC roof isolator (on the roof near the panels, if installed — required for modern installations)

Do NOT attempt to disconnect individual panel connectors during a storm — DC circuits can carry high voltage even in cloudy conditions.

Hail

Panel hail resistance: Standard solar panels are tested to IEC 61215, which includes impact testing with 25mm diameter hailstones at 23m/s. This represents the minimum standard; panels are not rated for golf-ball size (45mm+) hail at severe velocity.

Perth hail reality: Perth experiences hail events, primarily during thunderstorms in summer and autumn. Most Perth hail events produce small hailstones (5–20mm) — within panel test specifications. Severe hail events with large stones (35mm+) are relatively infrequent in Perth compared to southeast Queensland or Melbourne.

Signs of hail damage to panels:

• Visible cracks, chips, or broken glass on panel surface
• Dark spots visible from ground (internal damage to cells)
• Generation drop on specific strings or panels visible in monitoring data

Minor surface micro-cracks from small hailstones may not be visible from the ground but can reduce panel output over time. If you suspect hail damage after a significant storm, a thermal imaging inspection by a licensed solar inspector can identify affected panels.

Wind

Mounting system wind ratings: Solar mounting systems installed in WA are designed to meet Australian wind loading standards for the region's wind zone. Most Perth metro areas are Wind Zone D (coastal cyclonic-fringe requirements). The standard mounting systems (aluminium rails on screwed roof mounts) are engineered to handle design wind speeds for the local zone.

When wind becomes a problem:

• Panels that were not correctly secured during installation can loosen over time
• Roof penetration sealant can crack under thermal cycling and long-term weather exposure, creating potential water ingress

After high wind events: Check panels from ground level for any that appear tilted, shifted, or with visible gaps in the mounting. If rails or mounting brackets look damaged, or if you hear unusual movement from the roof, have a licensed solar electrician inspect before assuming the system is safe to operate.

Lightning

Direct lightning strike: A direct lightning strike on a solar array is extremely unlikely but would damage panels, inverters, and potentially the switchboard. Most inverters have some surge protection built-in; a direct strike would likely destroy the inverter.

Nearby lightning (induced surge): More common is the surge from nearby lightning that travels through the grid or through the DC wiring. This can damage inverter electronics.

What to do if lightning strikes very close to your property:

• Switch off the AC solar isolator and DC isolators if it's safe to do so
• After the storm, check your inverter monitoring app on the next sunny day
• If the inverter doesn't start generating normally, check for fault codes
• Contact your installer if the inverter shows a fault or doesn't recover

Surge protection: Some installers offer optional DC surge protection (SPD) on the DC wiring between panels and inverter. This is particularly relevant for rural properties with longer cable runs or properties in areas with frequent lightning activity. It's not standard in all Perth residential installations but worth considering for high-risk properties.

After a storm: what to check

From ground level (do not go on the roof after a storm without professional assessment):

1. Panel visual check: Any visible cracks, chips, or displaced panels?
2. Inverter: Is it showing a fault code or red light?
3. Roof structure: Any visible roof damage that might affect panel mounting?
4. Gutters and drainage: Any debris from installation area?
5. Monitoring app: Is generation normal on the next sunny day?

If you observe any damage: Don't attempt to inspect the roof or panel wiring yourself. Contact your installer or a licensed solar electrician. DC circuits in solar panels can carry lethal voltage even without grid connection, and damaged panels can be unpredictable.

Insurance and storm damage

Home and contents insurance: Most standard Australian home and contents policies cover solar panels for storm damage, fire, and similar insured events as part of the building structure. Confirm:

• Are solar panels specifically listed as part of the insured building structure (not as a separate item)?
• What excess applies?
• Does the policy cover inverter damage from surge/lightning?

Gaps to check: Some policies exclude panels from specific perils (e.g., hail, flood). Read your Product Disclosure Statement (PDS) for exclusions.

Making a storm damage claim:

• Document the damage with photos from the ground
• Do not attempt to repair damage before the insurer assesses it
• Get a quote from a CEC-accredited installer for repair or replacement
• Contact your insurer to report the event and initiate the claims process

Planning around Perth storm season

Perth's thunderstorm season runs roughly October–March. If you have a monitoring app on your phone, check it on the morning after any significant storm. A system that was generating well before the storm and shows reduced or zero output the next morning warrants investigation.

For properties with batteries, check the battery SoC (state of charge) readings and any fault codes in the battery management app — surge events can affect battery BMS electronics as well as inverters.

If your system shows a generation anomaly after a storm and you're not sure if it's a weather effect or a fault, check your monitoring data for the previous clear days to compare. A consistent drop from pre-storm baselines on sunny days indicates an active fault worth investigating.