Are you investing in solar — either a rooftop system at home or a large-scale solar farm? Then there’s one thing you absolutely cannot afford to ignore:
Lightning.
We all love the Aussie sun. We rely on it to power more than 4.16 million solar PV systems across the country — from small rooftops to massive solar farms producing over 41 GW of clean energy. And with more than 7 GW of large-scale solar already online (and another 27 projects on the way), solar really is becoming one of Australia’s biggest energy sources.
But here’s the truth nobody enjoys talking about:
Lightning and surges can destroy a solar PV installation in seconds.
It doesn’t matter whether you’re dealing with a 6.6 kW rooftop setup or a 300 MW solar farm stretching across 600 hectares in regional NSW — lightning is one of the most damaging, disruptive, and expensive risks solar owners face.
This article will help you understand lightning risks, why protection matters, and what you can do — even if:
- • the science seems overwhelming,
- • you’re not sure where to start,
- • or you think “it probably won’t happen to me.”
After reading this article, you’ll know exactly how to keep your solar system (and your wallet) safe.
Why Lightning Is a Real Threat to Solar — Not Just an “Occasional Risk”
You might be thinking:
“Lightning? Really? It’s not like storms happen every day.”
Fair point — but here’s something you may not realise.
Lightning risk is strongly connected to solar radiation.
Science has shown a clear link between:
- • high solar radiation,
- • high humidity, and
- • higher frequency of lightning discharges.
And where do we build solar farms?
Exactly — in places with the highest solar radiation.
So the very regions that are perfect for PV energy production are also the regions where systems are more exposed to lightning.
Risk grows with system size.
According to AS 1768 (Lightning Protection), risk assessment is based on:
- • the lightning frequency of the region (strikes/km²/year),
- • the area of the installation, and
- • the type of structure or system being protected.
Large solar farms can cover 1.5–2 hectares per MW.
So a 300 MW solar farm in south-central NSW (where the Bureau of Meteorology reports a lightning frequency of around 2) will likely experience:
- • 5 direct lightning strikes per year, and
- • 7 indirect strikes per year.
Over a 30-year service life?
That’s around 150 direct lightning strikes — not counting nearby ones.
Imagine the stress on equipment, metalwork, cabling, inverters, electronics, and monitoring systems.
It adds up.
What Happens When Lightning Hits a Solar PV System?
Think lightning only blows up panels? Nope.
The damage can be much more widespread.
Direct strike damage
This can destroy:
- • PV modules
- • cable trays
- • mounting frames
- • structural steel
- • combiner boxes
- • isolation devices
- • transformers
- • and even cause fires
A direct strike is like letting thousands of amps rip through your system instantly. Nothing enjoys that.
Indirect strike damage
This is where most real-life failures happen.
A lightning strike kilometres away can still induce:
- • surge voltages
- • electromagnetic interference
- • cable insulation breakdown
- • inverter failure
- • control system malfunction
- • monitoring/data equipment damage
And once sensitive electronics fail?
Production downtime begins.
For a large solar farm, that means:
- • lost generation
- • penalties for failing network obligations
- • costly repairs
- • replacement delays
- • performance guarantee failures
Solar farms are designed for 30 years of reliable production. Regular unplanned downtime can kill profitability.
Why You Should Take Lightning Seriously (Even for Rooftop Solar)
You might be thinking:
“This sounds like a big solar farm problem — not a home problem.”
But here’s the truth:
Rooftop solar is just as vulnerable.
Most Aussie homes don’t have lightning air terminals, but the risk is still real because:
- • the solar array is the highest point on the roof
- • the mounting frame is conductive
- • long DC strings act like antennas
- • inverters contain delicate semiconductor components
- • monitoring systems are extremely sensitive
Even a nearby strike can push thousands of volts into your system.
And typical home insurance? It may cover the damaged equipment, but it doesn’t cover:
- • lost feed-in tariff earnings
- • extended downtime
- • inverter replacement delays
- • data loss
- • damage to appliances downstream
Lightning protection isn’t just “extra safety.” It’s a direct protection for your investment.
Major Reasons Lightning Protection Matters in Australia
1. The Area Is Huge — So the Risk Is Huge
Large-scale PV farms spread across hundreds of hectares. That makes them massive lightning targets.
Example: A 600-hectare farm = a catchment area so large that you cannot realistically “avoid” lightning.
Tip: The bigger the site, the more essential dedicated lightning protection becomes.
2. High Solar Radiation = High Lightning Frequency
Australia’s solar hotspots (NSW, QLD, NT, SA) often have:
- • high humidity
- • convective weather
- • atmospheric instability
Perfect for solar production — and perfect for lightning.
Tip: If a location is good for solar, assume it’s also at higher lightning risk.
3. Downtime Is Expensive
Every minute a solar farm is down:
- • generation drops
- • revenue drops
- • performance guarantees are affected
- • investors get nervous
- • maintenance costs skyrocket
Tip: A single destroyed inverter can cost more than an entire surge protection system.
4. Lightning Damage Isn’t Always Visible
Some failures show up months later:
- • slow inverter degradation
- • drifting MPPT performance
- • intermittent comms faults
- • hotspotting on panels
- • earth system instability
Tip: You don’t want “invisible damage.” Protect your system from the start.
5. Modern Inverters Are Very Sensitive
Inverters contain:
- • IGBTs
- • MOSFETs
- • microcontrollers
- • sensors
- • communication circuits
Tip: SPDs (surge protective devices) are non-negotiable.
So What Can You Do? Here’s What Lightning Protection Should Include
Just like your sample article, let’s break this down into:
- • What the problem looks like
- • What to do about it
- • Practical tips
Problem #1: Direct Lightning Strikes
Direct strikes can completely destroy solar infrastructure.
Solution: Build a Proper Air Terminal System
- • structural lightning masts
- • rooftop air terminals
- • catenary wires
- • downconductors
- • bonding to earth grids
Tip: Never use the PV mounting frame as a lightning air terminal. It’s not designed for it.
Problem #2: Poor Earthing
A lightning protection system is useless without a low-resistance earth.
Solution: Install a High-Performance Earth Termination System
- • ring earths
- • multiple earth rods
- • dedicated downconductor earths
- • equipotential bonding
- • regular testing
Tip: Soil conditions matter — you may need soil enhancement compounds in dry inland areas.
Problem #3: Induced Surges on Long Cables
Long DC strings act like lightning antennas.
Solution: Install Surge Protective Devices (SPDs) in All Critical Locations
You need SPDs:
On the DC side:
At the array or combiner box.
On the inverter AC side:
- • If the inverter is within 10 m of the switchboard → SPD at the switchboard.
- • If the inverter is more than 10 m away → SPD at the switchboard and near the inverter output.
On data/communications lines:
- • monitoring equipment
- • SCADA
- • RS485
- • Ethernet
- • fibre converters
Tip: SPDs should always be replaced after major events — they sacrifice themselves to save your system.
Problem #4: Poor Bonding of Solar Frames
Improper frame bonding can cause:
- • dangerous touch voltages
- • inverter errors
- • panel degradation
- • unpredictable surge paths
Solution: Equipotential Bonding
- • PV frames
- • mounting structures
- • metallic conduits
- • cable trays
- • incoming earths
- • inverter enclosures
- • switchboards
Tip: Continuity testing of frame bonding should be part of every commissioning process.
How Lightning Protection Applies to Rooftop Solar
Let’s take the same approach as your sample article — simple and actionable.
You think your home isn’t at risk.
Many homeowners assume:
“It’s just a small roof system — why would lightning hit me?”
But here’s what you may not realise:
- • Your roof is the highest conductive surface.
- • Your PV array is often the tallest point.
- • Your DC cabling runs long distances.
- • Your inverter electronics are sensitive.
Even a nearby strike can damage your system.
What you can do:
- • Ensure panels and mounting systems are bonded.
- • Install a DC SPD on the array side.
- • Install an AC SPD at the switchboard.
- • Install a comms SPD if monitoring is integrated.
Tip: Even budget systems benefit hugely from basic surge protection.
You think surge protection is optional.
It’s not.
Here’s why:
- • A single $100 surge event can destroy a $2,000 inverter.
- • Failed inverters often take weeks to replace.
- • Warranty claims don’t always cover lightning.
- • Lost feed-in energy is never recoverable.
What you can do:
- • Install SPDs on:
- • the DC string
- • the AC output
- • the switchboard
- • communications lines
Tip: A full SPD set usually costs less than 1% of the system price.
You believe lightning protection is too expensive.
Let’s be real — lightning protection is an investment.
But consider the cost of:
- • inverter replacement
- • DC cable replacement
- • scorched combiner boxes
- • fire damage
- • production downtime
- • technician callouts
- • failed warranties
What you can do:
Compare the cost of:
- • full protection system
- • versus
- • a single lightning event
The difference is massive.
Tip: Most large-scale farms pay off their lightning protection in the first year — simply by avoiding one incident.
Takeaways: Keep Your Solar Protected
Here’s your final lightning protection “quiz,” following the style of your sample.
- 1. Lightning is only a problem for large solar farms.
False. Rooftop solar is also vulnerable through surges and induced voltages. - 2. SPDs are optional if you already have good earthing.
False. Earthing and SPDs work together — you need both. - 3. A solar farm in NSW can expect hundreds of lightning strikes over its lifetime.
True. A 300 MW site can expect around 150 direct strikes over 30 years. - 4. Lightning protection only prevents physical damage.
False. It also protects against downtime, lost revenue, and equipment degradation.
We design and manufacture high-quality switchboards. Contact us today to discuss your requirements and get started!