Most modular solar panels are made for outdoor weather, not for underwater operation. A panel can survive rain and cleaning yet still be unsafe or out of warranty if the junction box, connector pair, cable gland or inverter side is submerged. The safe answer is therefore conditional: use a modular solar panel near water only within the exact module, connector and electrical-system instructions; do not treat it as submersible unless the manufacturer documents that use case.
What the manufacturer manual actually says
The Canadian Solar PV module installation manual is a useful example of how mainstream PV manuals frame the issue. It says not to immerse modules in water or constantly expose them to fresh or salt water, notes that unmated connectors are not waterproof, and warns against placing connectors where water can easily accumulate. That is stronger practical guidance than a generic “waterproof panel” claim.
Does IP68 mean the whole panel can be submerged?
An IP67 or IP68 rating applies to the enclosure or product identified in its documentation under stated test conditions. On a module datasheet it may refer to the junction box or connector, rather than the whole module. It does not automatically approve a complete array for ponds, pools or floodwater. Check which part is rated, the specified exposure conditions, and whether connectors must be fully mated. If the installation manual prohibits immersion, an IP rating elsewhere on the datasheet does not override it.
| Situation | How to interpret it | Safer action |
|---|---|---|
| Rain, snow and normal wash-down | Usually within the intended outdoor use when the module is installed as instructed. | Follow the module manual for tilt, cable routing, cleaning pressure and connector handling. |
| Temporary site flooding | A fault condition, not a normal “submersible” use. | Do not touch a flooded array or wet electrical parts. Keep people away until a qualified person assesses and isolates the system. |
| Floating PV on reservoirs or ponds | Panels normally operate above the water on floats; this is not the same as underwater PV. | Use a floating-PV mounting design, corrosion plan and approved cable/connector routing. |
| Truly underwater equipment | A special product category requiring documented submersible modules, cables, connectors and power electronics. | Buy equipment specified for underwater service instead of adapting standard rooftop modules. |
Floating PV, buoys and real submersion are different projects
A floating solar plant usually keeps the module surface in air while the float, mooring and cable management handle the water environment. A buoy may carry a small panel above the waterline to charge instruments. For a submerged sensor, an above-water panel connected by suitably specified cabling may avoid putting the panel underwater. If the PV module itself must operate below the surface, every submerged part needs documented suitability for the actual depth, exposure and operating conditions. The optical design must also account for the light that reaches it; a dry rooftop output rating is not an underwater performance guarantee.
Checks before using panels near water
- Read the module installation manual, not only the sales sheet.
- Confirm connector brand, model and mated/unmated condition; unmated connectors may admit moisture.
- Route connectors and junction boxes away from low points where water can stand.
- Check corrosion exposure, especially salt spray, fertilizer, pool chemicals and agricultural runoff.
- For flood-prone sites, specify disconnects, ground-fault protection and post-flood inspection by qualified personnel.
The key distinction is weather resistance versus designed submersion. Standard modular panels may be excellent for rooftops, farms and off-grid systems in wet climates, but underwater operation requires product documentation for that exact duty.
What if a panel has already been underwater?
Drying the outside does not establish that the insulation, junction box or connector contacts remain serviceable. Record the module and connector models, approximate exposure and whether the water was fresh, salty or contaminated, and pass those details to the installer and manufacturer. Follow their inspection or replacement decision before re-energising the affected equipment; a normal-looking glass surface is insufficient evidence of electrical condition.