It's rare to come across an 'arc box' prior to encountering an issue with one, and when this does occur, it's not often understood as a priority. These small devices are a part of the direct current (DC) side of your solar system, providing protection for it, and, unfortunately, not one to be loved or greatly maintained by those who've had solar panels fitted to their roof. I've had the privilege of seeing numerous systems like this, and have witnessed the areas in which they are commonly vulnerable.

An insight into what arc boxes do on a solar system

Arc boxes (also sometimes known as arc fault detectors or DC protection units) are used to detect dangerous arcing in the DC wiring of a solar system, and shut it down to prevent fire. These can be seen as the 'smoke alarm' of a solar system's cabling. Not all solar systems will have one, although it's common to see them fitted in newer systems, where the DC wiring requires additional protection, particularly where it's closer to roof structures. Arc boxes themselves are small, and can be easily overlooked.

The effects of the conditions on a roof on electrical equipment

Rain, frost, heat, wind, UV. British weather beats down all manner of electrical equipment fitted to a roof, and anything close to the solar panels and cabling has to endure it. Seals deteriorate, fixings become loose, and small faults in equipment such as connections occur. In addition, the area around the array is a prime nesting area for birds. Weather and wildlife alike can take their toll on electrical equipment, and neither takes a preference for the value of a system.

How pigeons are drawn to the components under solar arrays

Pigeons require sheltered, dry, and warm spaces to nest, and the area under a solar array provides all three. This is also where cabling, connectors and protection units are commonly found. Once a nest forms within this area, twigs, feathers, and deposits are frequently found nestled among cabling and components for a period of weeks or months, and can go unnoticed due to the area being unreachable.

Droppings, damp and corroded connections

Bird droppings are acidic in nature, and hold moisture, both of which are unwanted when it comes to connections. If left on connections long term, they can corrode joints, weakening insulation and connections. Poor connections generate heat, as do most protection devices, and this is what they are designed to respond to. It can be said that birds cause the issues that protection equipment aims to respond to. It's a gradual process, and therefore overlooked, until a fault code appears.

I'm not advocating panic, as a majority of nests rarely ever ignite. Dry twigs, grasses, and feathers can pose a potential hazard if placed in contact with hot components, as it's the fuel for fire. It's not a likely occurrence, but it's one that doesn't require much to happen.

Solar panel netting is the practical solution

The simplest way to prevent the above is to keep the access to the gap beneath the solar array closed in the first place. Solar panel netting is a tough mesh which, when fitted to the edge of the array, prevents pigeons from accessing the area beneath it. This is done in a way that they can't get under the mesh, and therefore can't nest in the nook beneath the solar array. Most netting is either dark-coated or stainless, and is not noticeable from the ground, having no effect on the shading of the glass when fitted correctly.

Clear the mess before anything else is fitted

This is where people often make mistakes. If there are existing nests and mess beneath the panels, fitting mesh to the edge of the array will keep all of this trapped beneath it. Fit mesh over an area of droppings, and the smell, bacteria, and mess will remain there indefinitely. Always wear a mask, gloves, and appropriate eye protection when removing the mess, and dampen it slightly to reduce airborne dust. Clean, disinfect, and allow the area to dry fully before mesh is fitted. It will last considerably longer, and it's far neater than leaving the mess be.

Don't allow the incorrect fitting of mesh to create more of a problem

I've seen examples of mesh fitting gone wrong, where gaps appear at the corners, or mesh is loose and exposed. Fixings can also scratch frames, or crack the glass of the array. More worryingly, I've witnessed people drilling and screwing fittings to the edge of the array, close to cabling. Always ask whoever is fitting the mesh to ensure they fix to the frame, and not anywhere dangerously close to cabling. Ask how they intend to fix it, and whether it can affect your warranty. A proper fitting should make it more secure, not less.

When to call in a professional

If you're unsure as to what's beneath your panels, or what could be, don't attempt to tackle it yourself. Electrical components and roof conditions aren't recommended to be dealt with incorrectly. A qualified person can check the wiring and protection units, clear the mess, and fit mesh in one appointment, and is a lot safer than attempting to do it yourself. It also removes the need to pay twice, once to have it fitted, and once to have it resolved.

How to build a simple checking routine

You don't need to be qualified as a roofer to look at the condition of your array from the ground, and to check for birds nesting or droppings. Do this at least twice a year, preferably just prior to any nesting season, and again in autumn. Keep an eye on your monitoring app for any strange fluctuations or error codes, and observe the area for signs of birds, droppings, or nest material poking out from the edge of the array. If you're concerned about the condition of your system, get it checked sooner than later. It's far cheaper to replace a small fault in month one than it is in year four.

In summary

The short version of this is that arc boxes and the wiring they protect on a solar system are best suited to a clean and bird-free area. Clear any mess properly, and keep it that way, fitting some strong solar panel netting to the edge of the array to keep pigeons out, and keep an eye on the roof to spot any nests that might be forming. It's a small task to maintain, and you reap the rewards of a well-kept system. If you'd like this to be performed correctly without the guesswork, contact Pigeon Proofing Solar Panels and allow us to help you keep your system safe and free of birds.

Name: Pigeon Proofing Solar Panels LTD

Address: 27 St Cuthberts Street, Bedford, MK40 3JG, UK

Phone: 01234 816257 

FAQs

Do arc boxes need checking?

It's a good idea to have them inspected as part of any system inspection, and if you have had bird activity in the area, have them checked over by a qualified electrician.

Can pigeons damage solar panel wiring?

Pigeons can damage solar panel wiring through nesting, pecking at the panels, and acid droppings. They're generally a gradual process, and don't occur quickly.

Does solar panel netting affect panel performance?

Not when fitted correctly. Netting is a sturdy mesh which is fitted to the edge of the array, preventing access to the area beneath it. It doesn't cover the glass of the array.

Should I clean under the panels before fitting netting?

Always. Fitting mesh over existing nests will keep the mess firmly trapped beneath the mesh, so it's best to clear and disinfect the area before anything is fitted.