Securing a PV installation: what to protect and how

Securing a PV installation means protecting it physically: a security fence around the perimeter, anti-theft clamps and security bolts on the modules, a corrosion-proof structure that survives the weather, and managed clearance around the array. A solar installation is a valuable, unattended asset standing in the open for decades, so the threats it faces are theft, storm damage, corrosion and unauthorised access rather than anything electrical. This guide covers what a PV installation is vulnerable to and the physical measures that protect it. For the perimeter itself see our guide to industrial and security fencing.

What a PV installation is vulnerable to

A ground-mounted array or solar farm faces a handful of physical risks. Modules and copper cabling are valuable and portable, so theft is the first concern, especially on remote unattended sites. Wind and snow can damage a poorly built or poorly founded structure. Corrosion slowly attacks any part made from the wrong metal or left with a bare cut edge. Overgrown vegetation shades the array and, in dry seasons, raises the fire risk, while animals and intruders can damage cabling and modules. Each of these is a physical problem with a physical answer, which is where the structure, the fence and the fixings come in.

The perimeter fence

The first line of defence is a security fence around the whole installation. A welded mesh or palisade fence, galvanised and often powder-coated, keeps out intruders and stock and marks the boundary clearly. Height, mesh aperture and the detail at ground level all decide how hard the fence is to climb or breach, and gates are the weak point that has to match the fence line. Because a solar site sits in the open for its whole life, the fence is galvanised for a long corrosion life and its posts are founded to resist the wind. For the options see our guide to industrial and security fencing.

Anti-theft module fixings

Beyond the fence, the modules themselves can be secured to the structure so they cannot be lifted off quickly. Security clamps and one-way, or tamper-resistant, bolts replace the standard clamps at the module frame, so a thief cannot simply undo the fixings with a common tool. On a large array only the perimeter and accessible rows may need them, while a rooftop array is largely protected by height. These fixings turn a quick, quiet theft into a slow, noticeable one, which is often enough to deter it. They fit the same rails as the standard clamps, so they are specified at the order stage.

A structure that survives the weather

The most reliable security measure is a structure that simply does not fail. A frame sized to the Eurocode wind and snow loads for the site, on foundations driven or cast to suit the ground, does not lean or lift in a storm. Building it in galvanised steel and EN AW-6060 T6 aluminium, with stainless fasteners, means no part rusts through over the twenty-five-year-plus life of the array. Manufacturing the structural components under EN 1090 gives the documented strength behind that. A structure that stays sound is one less thing to fail while the site is unattended.

Corrosion as a slow threat

Corrosion is the threat that acts slowly and is easy to overlook. A bare carbon-steel part in a wet joint, a cut galvanised edge left unprotected, or a mix of dissimilar metals in a damp detail will all corrode over years and can loosen a fixing or weaken a member. The defences are simple: use aluminium and stainless at the exposed surface, galvanise the steel, re-protect any cut edge with zinc-rich paint, and never couple bare steel to aluminium in a wet joint. Choosing the right metals at the start is far cheaper than repairing a corroded array later.

Access, gates and clearance

How people and machinery reach the array is part of securing it. Gates are sized for maintenance vehicles yet detailed to be as secure as the fence, because an easy gate undoes a good fence. Inside the perimeter, keeping vegetation cut back stops plants shading the modules and reduces the dry-season fire load, and it keeps the fence line clear so a breach cannot hide behind growth. Clear access routes also let inspection and cleaning happen safely. This everyday clearance management protects both the output and the security of the site over its life.

Rooftop versus ground-level security

Where the array sits changes the security it needs. A rooftop array is protected by height and by the building itself, so theft is harder and a perimeter fence is rarely the issue; there the concern is a sound, well-anchored structure that does not lift in a storm and does not corrode where it cannot easily be inspected. A ground-mounted array or a solar farm is the opposite case: it stands open and accessible, so the perimeter fence, the anti-theft fixings and the site clearance all carry real weight. Matching the measures to the location, rather than applying the same checklist everywhere, is what makes the spend on security count.

Designing security in from the start

The cheapest security is the kind designed in before the array is built. Setting the fence line, the gate positions and the anti-theft fixings at the design stage costs little, while retrofitting them to a live site is disruptive and dearer. It also lets the fence foundations, the array foundations and the access routes be planned together, so nothing has to be dug twice. Choosing the right metals for the whole structure at this stage, galvanised steel, aluminium and stainless, builds in the corrosion resistance that keeps the site sound for decades. Security planned in from the start is quietly effective; security bolted on later is always a compromise.

Layered deterrence

No single measure secures a site on its own, so the measures are layered into a defence in depth. A secure perimeter fence, tamper-resistant module fixings, cabling carried out of reach and controlled gates each cover a different weakness, and together they mean no one gap opens the whole installation. The point of layering is that a determined intruder has to defeat several barriers in turn rather than one, while an opportunist is turned away at the first. Visible security is itself a deterrent, because most theft goes to the easiest target: a site that plainly has a sound fence, locked gates and modules bolted down with tamper-resistant fixings reads as slow and risky, so a thief moves on to somewhere softer. Designing the layers to work together, rather than relying on any one strong barrier, is what gives a solar site security that holds up when it is tested.

Where the electrical side takes over

Physical security is only part of the picture, and it stops where the electrical and monitoring systems begin. Lightning and surge protection, earthing design, fire safety, alarms, cameras and remote monitoring are all specialist and electrical work, designed and installed by the relevant contractor, not part of the mounting supply. ULAMEX supplies the physical structure and the fencing that protect the installation, and works alongside those systems rather than replacing them. Knowing where the mechanical scope ends, and where the electrical and monitoring scope begins, keeps the responsibilities clear and the site properly protected on every project.

Insurance and site risk

Physical security is not only about stopping a loss, it is often a condition of covering one. Insurers of solar installations commonly expect a secure perimeter, controlled access and a sound structure before they will write or price a policy, so the fence, the gates and the anti-theft fixings can lower the cost of insuring the site as well as the risk to it. A well-founded, corrosion-proof structure that meets its wind and snow loads also reduces the storm-damage exposure that drives claims. Treating security as part of the risk case for the whole project, rather than an afterthought, tends to pay back in both cover and peace of mind over the life of the plant.

Protecting the cabling and equipment

Beyond the modules, the cabling and the equipment are worth protecting physically. Direct-current cabling carried in a trench or in trunking along the structure is out of reach and out of the weather, which deters the copper theft that targets exposed runs. Inverters and switchgear are usually housed in a locked cabinet or a small enclosure, and where that enclosure sits on a steel frame or against a structure, ULAMEX can supply the supporting steelwork. Keeping the cabling clipped up off the ground and the equipment behind a locked door removes the easy, opportunist targets, so the array is protected in depth rather than at the fence line alone. The electrical design of these systems remains the installer’s, but the physical housing is structural.

Physical security from ULAMEX

ULAMEX manufactures PV mounting and fencing structures under EN 1090 and has supplied the trade since 1988.

Securing a solar site? Send the site layout and perimeter length, and ULAMEX will return a non-binding quotation with lead time and availability. Read the full PV mounting systems guide, see our modern aluminium fencing and security fencing options, or view our supply capabilities. Contact the export desk at [email protected] or +48 504 424 761.

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