Across South African mines, the economics of self-generation have won the argument. Rooftop and ground-mount solar, increasingly paired with battery storage, are going up fast to cut diesel and ride through an unreliable grid. The panels arrive on a project timeline. The protection they need in order to be safe rarely keeps the same pace — and that gap is now a live compliance and asset-protection issue.
Why solar and batteries change the risk
From a lightning and earthing point of view, a solar installation is a large new metallic structure you did not have before. It presents a big collector area to the sky, sits high and exposed on roofs or open ground, and threads sensitive electronics — inverters, battery management systems, communications — through the middle of it. Add a battery energy storage system (BESS) and you also have a dense, high-energy store that does not tolerate a surge or an earthing fault gracefully. None of this was in the original protection design of most sites.
DC is a different animal
AC systems have a natural ally: the current crosses zero fifty times a second, which helps faults and arcs extinguish themselves. The DC side of a PV array has no such help. A DC arc, once struck, tends to sustain — which is why the DC side needs surge protective devices rated and coordinated specifically for DC, correctly placed between the array, the combiner and the inverter. Fit an AC-logic SPD to a DC string, or leave the string side unprotected, and you have introduced a fault mode the rest of your site never had.
The battery container is its own problem
A battery container concentrates a great deal of energy in a small metal box, usually outdoors, usually bonded into the site earth. Its earthing and bonding have to be right — for touch-and-step safety, for the surge paths into the battery-management and inverter electronics, and to keep a fault from finding an unintended route. A BESS is not a shipping container with cells in it; it is part of the electrical installation, and it must be earthed, bonded and surge-protected as one.
What the standards now expect
The standards have moved with the technology. SANS 10142-1, in its 2024 edition, sets out specific verification requirements for photovoltaic installations. Adding a large array also changes the lightning risk picture — a trigger to revisit the risk assessment under the SANS and IEC 62305 series rather than assume the old one still holds. Coordinated surge protection follows the SANS and IEC 61643 families on both the AC and DC sides, and earth measurement is done to IEEE 81. The through-line is simple: PV and BESS are not exempt from the protection regime — they extend it.
Your old earthing design didn’t include any of this
Here is the practical trap. On most sites, the earthing and lightning protection were designed and certified before the solar existed. Bolting an array onto that system does not automatically bring the array — or the rest of the site — back into compliance. The down-conductor routing, the separation distances, the equipotential bonding and the SPD coordination all have to be reassessed against what is actually there now. A certificate issued for the pre-solar site says nothing about the panels on the roof.
Why this becomes a monitoring problem too
Self-generation also multiplies the things that can quietly fail. More SPDs means more devices that can reach end-of-life unseen. A large, spread-out array and a remote BESS are exactly the kind of assets where a stolen bond or a degraded earth goes unnoticed until it matters. This is why continuous assurance fits PV and BESS so naturally: the same monitoring that watches your earthing and surge protection can watch the new DC world you have added, so a problem on the solar side is caught while it is still small.
The panels were a good decision. The risk is only that the protection didn't arrive with them — and that gap is straightforward to close, once you decide to look at it.