Salt Air and Solar. What Coastal Homeowners Should Know

A lot of the homes we work on are close to the water. Think the Northern Beaches, Manly and the Eastern Suburbs. Salt air is part of life there. It's also hard on anything sitting on a roof for 25 years.

What "class 6" salt mist actually means

Panels can be tested for salt resistance under a standard called IEC 61701. Severity 6 is the level you'll often hear called class 6. In plain terms, the panel goes through eight weekly cycles, 56 days in total. Each week it's sprayed with salt water four times, kept hot and humid in between, then left to dry out for three days.

REC and salt testing

We use REC a lot near the coast. REC lists IEC 61701 salt mist at severity 6 on its Alpha Pure-R and Alpha Pure-RX datasheets. To be candid with you, the latest Pure-RX datasheet marks that cert as optional. So we check the certificate for the exact model going on your roof. REC's manual also says panels shouldn't go where they're in direct contact with salt water or spray. Fair enough.

What goes wrong with the wrong panels

Lower quality panels that aren't warranted for use near the water tend to fail the same way. Frames corrode where they meet the mounting. Junction boxes and connectors corrode, which can lead to faults. Moisture gets in and the layers inside can start to separate. Output drops.

Then there's the warranty. Some manufacturers set conditions based on distance from the coastline. Some want extra corrosion protection within 500 metres of the sea. If the install doesn't meet those conditions, the warranty may not cover you.

Fixings, batteries and upkeep

Salt speeds up galvanic corrosion. That's what happens when two different metals touch. We use stainless steel or aluminium where parts contact the panels, and keep dissimilar metals apart.

For batteries and inverters, we look at the IP rating and the maker's coastal rules. From what we can tell, some set a minimum distance from the sea. Most want the unit sheltered from direct sun and rain. A side wall or garage usually beats a wall facing the ocean.

Salt builds up on the glass too. Follow the panel maker's cleaning instructions and get the system checked now and then.

The short version. Ask for the salt mist certificate for the exact panel. Ask what the warranty says about coastal distance. Ask what the fixings are made of and where the battery will sit. Top end products hold up a lot better by the water.

If you're near the coast and want a second opinion, give us a shout.