Last summer, my neighbor’s system went down during a typhoon. Not because the panels blew off—they were fine. The inverter just… stopped. No warning, no error code, nothing useful on the app. Just a dead screen and a sinking feeling.
The installer came out two weeks later. “Water got in,” he said, pointing to a tiny crack in the housing. “Happens all the time.”
That stuck with me. Because we spend so much time obsessing over panel efficiency and payback periods, but almost nobody talks about what actually kills these systems. And in most cases, it’s not the sun—it’s the rain.
What Actually Happens in a Storm
When a typhoon or heavy rain hits, three things go wrong:
First, water ingress. Not a flood—just persistent moisture. Wind-driven rain gets pushed into places it wouldn’t normally reach. A connector that seemed tight in dry weather might have a gap you can’t see, and that gap becomes a channel.
Second, salt corrosion. If you live anywhere near the coast, this is your real enemy. Salt mist gets into the junction boxes, eats through the copper, and increases resistance. Higher resistance means more heat. More heat means faster degradation. It’s a slow death, but it’s predictable.
Third, voltage spikes. Lightning doesn’t have to strike your house directly. A nearby strike can induce surges through the grid or the DC lines. If your inverter doesn’t have Type 1 or Type 2 surge protection built in, those spikes will take out the sensitive electronics instantly.
The Two-Minute Check That Saves Thousands
You don’t need to be an electrician to catch most problems early. Here’s what I do before every rainy season:
Look at the connectors. Are they fully engaged? Can you see any discoloration or melting around the plastic housing? A brownish tint means heat damage.
Feel the cables. They should be cool to the touch. If any section feels warm on a cloudy day, you have a resistance issue.
Check the drain holes. Most outdoor inverters have small openings at the bottom for condensation to escape. People accidentally cover these during installation, or insects build nests in them. Clear them out.
Test the RCD (residual current device) monthly. There’s usually a test button. Press it. If the inverter doesn’t trip, call someone.
When to Just Turn It Off
Here’s a counterintuitive piece of advice: during an extreme storm, consider shutting the system down manually.
I know, it feels wrong to stop generating when the sun is still out. But if the grid is unstable, or if you’re in a coastal area with flying debris, the risk of surge damage outweighs the lost generation. You can lose a whole day’s production, or you can lose the whole inverter.
The procedure is simple: flip the AC breaker first, then the DC switch. Wait for the display to go dark. After the storm passes, restart in reverse order. This isolates the inverter from both sides and gives it a clean power-up sequence.
Your inverter is more resilient than you think. But it’s also more fragile than the marketing materials suggest. The difference between a ten-year system and a three-year system is rarely the brand—it’s the care you take before the weather turns.
My neighbor replaced his inverter that fall. The new one sits higher on the wall, with better cable management and a proper drip loop. He still rolls his eyes when he talks about the old one.
He should. That one didn’t fail—he just didn’t know what to look for. Now you do.
