With Cyclone Alfred making its way toward Queensland, many homeowners with solar battery systems are concerned about the impact of the storm on their installations. While cyclones and severe storms can pose challenges, it is important to note that modern solar battery systems are designed with protective measures to withstand harsh weather conditions. Taking the right steps before, during, and after a cyclone is crucial to ensuring your system remains safe and functional. This blog covers practical advice and frequently asked questions on protecting your solar battery system during a storm.

Advice for Homeowners after Cyclones and Storms

1. What are the risks of storms to solar and battery systems?

• Extreme weather and suboptimal installation practices can lead to significant damage of the equipment and possibly unsafe situations. While installation techniques may have been compliant with available standards at the time, they may not always follow the most current best practices for storm resilience.
• Extreme winds can rip solar panels from their mounting systems. Panels, which can be as large as 2 meters tall and weigh up to 25 kilograms, are vulnerable to being dislodged during high winds. When detached, these panels can become dangerous projectiles, causing damage to property and posing a hazard to people.
• Storm debris such as hail, flying branches, or unsecured objects can hit system components, resulting in damage and possible electrical faults. The impact can compromise the physical integrity of the panels and inverters but also lead to electrical hazards if the protective casings are broken.
• Heavy rainfall and flooding present another serious risk. Water entering electrical components such as inverters, battery storage, and junction boxes may cause immediate and potentially irreversible damage. Even after the storm passes, trapped water can continue to cause malfunctions or corrosion, leading to system failure over time.
• Solar systems continue to generate electricity even when disconnected from the grid. These systems can cause severe electrical arcs if water has entered electrical components. This is a risk for fires or electrical shocks as long as sunlight is hitting the panels even if the system is switched off.

Figure 1: Damaged MC4 cables, possibly due to internal arcing.

2. Is Shutting Down Your Solar Battery System Necessary?

Shutting down the system is not necessarily advised during a cyclone for most modern solar battery systems, especially if you have a battery backup. Here’s why:

• Built-in Safety Features: Solar battery systems are equipped with protections against electrical faults, overvoltage, and abnormal conditions. These features help to prevent damage from extreme weather and possible grid disconnections.
• Self-protection and Monitoring: Many systems have automatic shutdown and restart features which allow the system to disconnect from the grid and protect itself from power surges or unsafe conditions. Well installed systems have water ingress protection for all components and are able to withstand high volumes of rain. Installers are required to mechanically secure all components so that they can withstand high winds conditions.

3. When Should You Shut Down the System?

While most systems are designed to handle cyclones, some conditions may warrant a shutdown:

• Flooding Risk: Turning off the system is recommended for batteries that may be submerged underwater due to flooding. Water and electricity are a dangerous combination, and electrical systems submerged in water can pose significant safety risks.

• Severe Damage to Roof or Solar Panels: It might be better to shut down the system temporarily to prevent further electrical hazards if high winds or debris are causing significant damage to your roof or solar panels. Contact your installer for specific advice on how to handle this situation. Panels falling from the roof or having clear cracks must be isolated. For information on how to shut your system down, look for SHUTDOWN PROCEDURE labels at your switchboard and system documentation, or search online for the manufacturer and model of each component.

Figure 2. Example of a typical solar battery system shutdown procedure.

4. After the Cyclone: What to Do if Your Solar Battery System Was Affected

Once the cyclone or storm has passed, it’s crucial to ensure the safety of your solar battery system before attempting to use it again. If you suspect any damage or exposure to water, follow these steps:

1. Do Not Attempt to Restart the System Immediately: It is important to avoid restarting the system without proper checks. A system exposed to flooding or damage can present serious hazards.
2. Professional Inspection: After exposure to water, have your system inspected by a qualified professional. They can test the integrity of the system and ensure that it is safe to use. Most installers are able to conduct inspections on systems. For assistance, please reach out to GSES, and we can recommend trusted inspectors near you.

5. What to do if your Solar Battery System was Submerged in Water

If your solar battery system was submerged during a cyclone or flooding, do not attempt to reconnect or turn it back on until it has been inspected by a qualified technician. Here’s why:

• Risk of Short Circuits and Fires: Submerged electrical components can lead to dangerous short circuits when powered on. Water can cause electrical arcs. Even if the system looks dry, internal components may still be compromised.
• Lithium-ion Batteries: Lithium-ion battery manufacturers recommend replacing batteries after a flood if the battery is submerged. It is not recommended to attempt to re-connect the battery in these situations. Water ingress can damage the electrical components responsible for keeping the system safe.
• Preventative Measures: To avoid water damage, the inverter and battery storage should be installed in a well-protected, elevated area where flooding risk is minimal. Many solar battery systems are designed with waterproof enclosures that offer protection. These enclosures are built to keep moisture out, protecting the internal components of the battery and inverter from water damage. Homeowners should check the IP rating (Ingress Protection rating) of their system to determine the level of water resistance. The manufacturer’s manual will typically specify the IP rating, with higher numbers indicating greater protection against water.

Figure 3. Electrical components enclosure with water ingress

Advice for Installers after Cyclones and Storms

Before restarting any system, perform a comprehensive inspection to ensure it is safe to operate:

1. General Safety Checks

• Look for signs of fire, smoke, arcs, or fumes around the inverter, battery storage, and wiring.
• Check for loose cables and equipment that seems to be overheating.
• Ensure there are no fallen tree branches or other debris around the system that could pose a safety risk.
• Verify that all components are stable and there are no signs of puncturing or physical damage to the batteries.

2. Flooding and Water Damage

• If the system was exposed to water, inspect for any signs of water ingress, corrosion, or leakage in components such as the inverter, battery storage, isolators and electrical connections.
• Check MC4s for moisture and do tug tests to ensure all connections are tight.
• Check for any error codes on the inverter or Battery Management System (BMS) which can indicate issues caused by water exposure.
• Make sure to wait for the system to be completely dry before turning it back on since water may have entered the cable disconnection points which could lead to earth faults.

3. Damage to Panels and Inverter

• Inspect solar panels for cracks, breakage, or loose connections. Panels may have been dislodged by strong winds or flying debris.
• Ensure that all clamps are still secured tightly.
• Check the inverter and charge controllers for any visible damage like scorch marks or signs of arcing, which could indicate electrical faults caused by power surges or lightning.
• Avoid turning the system on if any of the panels or inverters have signs of physical damage.

4. Electrical Safety Checks

• Ensure Proper Disconnection: Before conducting any checks, ensure the system is fully disconnected by following the standard shutdown procedure. This includes turning off the DC isolator, AC isolator, and disconnecting from the grid. A full shutdown procedure can typically be found in the manufacturer’s manuals.
• Inspect Components for Short Circuits or Damage:
  • Batteries: Check batteries for any visible damage or leakage. Lithium-ion batteries can be prone to thermal runaway if they are damaged during a storm. If you suspect any fire risk, avoid manually interacting with the batteries and contact emergency services if needed.
  • Surge Protection: Verify that surge protection devices (SPDs) were properly installed and assess their condition. If damaged, these need to be replaced immediately.
• Use of Thermal Cameras: If available, use infrared (IR) cameras to detect hot spots or other hidden damage in the system’s components. This is especially helpful for identifying internal damage to panels or inverters that may not be immediately visible.
• Reconnection: Once all checks have been completed and the system is cleared, follow the return-to-service checklist to safely reconnect the system. Perform a final test to ensure that it is functioning properly.

Figure 4. Using IR cameras can help detect hot spots and otherwise hidden signs of damage.

Electrical Risks in a Flooded Solar PV System: DC Voltage in Water

If your solar battery system gets flooded, it can pose serious electrical danger even after the storm has passed. One of the biggest risks is that solar panels keep producing electricity as long as there is sunlight, even if your home’s power is off. This means that flood water around your system could carry live electrical current, increasing the risk of electrocution. To stay safe, assume that any flood water near a submerged solar system could be electrified. If your system is affected by flooding, wait until a qualified technician inspects your system before attempting to use it again.

To minimize risk, here are some important safety measures:

• Do Not Enter Floodwaters: Always assume the floodwater is electrified and avoid wading through or touching water near the solar system.
• Automatic Shutdown Systems: Ensure the system is equipped with rapid shutdown systems or emergency DC disconnects to isolate the solar panels in case of flooding, preventing current from propagating through the water.
• Residual Current Devices (RCDs): Install RCDs or ground fault detection and interruption (GFDI) devices to detect leakage currents and disconnect the system automatically if an electrical fault occurs.
• Elevated Installation: If possible, elevate critical electrical components like inverters, junction boxes, and wiring above expected flood levels to reduce contact with water during floods.
• Post-Flood Inspections: After floodwaters recede, contact a qualified technician to inspect the system. They will test for insulation resistance, check connectors, and assess the integrity of inverters, wiring, and panels before re-energizing the system

Frequently Asked Questions (FAQ)

Q1: Should I turn off my solar battery system before a cyclone hits?

A1: It’s not always necessary unless there’s a significant risk of flooding or environmental damage. However, if your system is at risk, it’s safer to shut it down.

Q2: Will my solar battery system provide backup power during a cyclone?

A2: If your system includes battery storage, it will provide backup power during an outage. Ensure that your batteries are fully charged ahead of time for maximum capacity. Some batteries are equipped with ‘Storm mode’. Check the manufacturer’s website for more information.

Q3: Can I turn my solar system back on if it was submerged in water during the cyclone?

A3: Do not attempt to reconnect your system after floods. It should be inspected by a qualified technician to ensure it is safe to operate.

Q4: How can I protect my solar battery system from damage during a cyclone?

A4: Ensure your system is securely mounted and remove any loose objects from around batteries and inverters. Do not attempt to move any solar or battery equipment. If necessary, contact a professional installer to help secure it before the storm.

Q5: Who do I contact for specific concerns?

A5: Here’s who to contact for specific concerns regarding your solar battery system:

• Installer or Technician:
  • If you are unsure about how to shut down or secure your system or if you need adjustments before the storm, contact your installer or a certified technician.
  • After the cyclone, reach out for a safety inspection if there’s visible damage or flooding.
  • Installers should also contact the manufacturer for specific guidance regarding any system-related issues.
• Distribution Network Service Provider (DNSP):
  • If your system is grid-connected and you experience an outage or other grid-related issues after the storm, contact your DNSP for assistance.
  • The DNSP can provide advice regarding the local grid and assist with any power interruptions.
• Emergency Services:
  • In the event of flooding or electrical hazards, contact emergency services immediately.
  • Do not attempt to handle exposed electrical components yourself.
• Insurance Provider:
  • If your system is damaged during the storm, contact your insurance provider to report the damage and check your coverage for solar systems.