Coastal PV Protection at Shuaibah: NEUTRON SPD and Corrosion Scope

1. Coastal site constraints

Unlike an inland desert site, the coast adds salt-laden air and high humidity. These attack metal surfaces and change the way leakage current behaves on the DC side, so the enclosure and the surge scheme must be specified for a marine-adjacent environment.

2. Corrosion-class enclosures

• Combiner and switchgear enclosures specified to a corrosion class suited to salt mist.
• Coated metal parts and sealed gaskets to slow ingress.
• Cable glands and entry points sealed against humidity.

3. Staged DC surge protection

NEUTRON applied a staged SPD scheme: each combiner carries a Type 2 DC SPD matched to the 1500 V envelope, while the plant interface carries coordinated protection. Staging stops a single surge event from stressing every device at once.

4. Combiner and switchgear scope

• PV combiner boxes rated to 1500 V DC with individual gPV fuse protection.
• DC MCBs for auxiliary circuits, DC-rated per IEC 60947-2.
• Low-voltage switchgear at the substation built to IEC 61439.
• Ring main unit for the grid connection interface.

5. Lightning and soil conditions

The SPD staging was reviewed against the local lightning density and soil resistivity so the protective earth and the arrester coordination matched the site, not a generic assumption.

6. Outcome

The coastal-rated protection scope gave the plant a durable first line of defence against both corrosion and surge. The lesson is that a seaside PV plant needs a different enclosure and SPD strategy than an inland one.