Squirrels love the sheltered gap between rooftop solar panels and your roof. It’s warm, dry, and protected from predators, making it ideal nesting habitat. The problem is that squirrels chew, and the wiring that connects your panels is exactly the kind of thing they chew through. The result ranges from a silent drop in energy production to expensive electrical repairs.
Why Squirrels Target Solar Panels
The space under a solar array typically sits a few inches off the roof surface, creating a pocket that stays warm in winter and shaded in summer. Squirrels recognize this as prime real estate. They’ll stuff the gap with twigs, leaves, insulation pulled from elsewhere on your roof, and whatever else they can carry. Once established, they treat the area like any other nest site, returning season after season.
The real danger isn’t the nesting itself. It’s the wiring. DC cables run between panels, and squirrels gnaw through the plastic sheathing the same way they’d strip bark from a branch. If they sever the right cable, an entire panel or string of panels goes offline. Worse, exposed copper wiring creates a short circuit or arc fault risk, which in rare cases can cause a roof fire. Even minor chewing that doesn’t fully cut a wire can degrade your system’s output for months before anyone notices.
How to Tell Squirrels Are Nesting
The signs fall into two categories: what you can see from the ground and what your monitoring system tells you.
Physical evidence is the most obvious. Look for twigs, leaves, acorn shells, or shredded insulation material tucked along the edges of your panels or scattered on the roof near the array. You might also hear scratching or scurrying on the roof, especially in the morning. If you can safely view the panel edges (binoculars work), check for bite marks on visible conduit or cable sheathing hanging loose.
Your monitoring app often catches the problem before you do. A sudden production drop on one panel or a string of panels that doesn’t match the weather is a red flag. If you use microinverters, a damaged panel will show up as a dimmer tile on the site map or trigger an alert, usually within a day or two of the chewing. If your whole system’s output gradually declines without an obvious cause like cloud cover or dirty panels, wiring damage is worth investigating.
If you spot stripped insulation or exposed wires, don’t touch anything. Shut the system off at the inverter and call a licensed solar installer. DC wiring under active panels carries voltage whenever there’s sunlight, and damaged cables are an electrocution hazard.
Critter Guards: The Main Solution
A critter guard is a wire mesh barrier that clips around the perimeter of your solar array, sealing off the gap between the panels and the roof. Most guards use 19-gauge galvanized steel wire with a half-inch mesh opening, coated in black PVC so they blend in visually with the panels. They attach with stainless steel clips that hook onto the panel frames, so no drilling into your roof is required.
The mesh is fine enough to block squirrels, birds, and rodents while still allowing airflow underneath the panels (which they need to stay cool and operate efficiently). A properly installed critter guard essentially turns your array into a sealed box that wildlife can’t enter.
Professional installation costs depend on system size. For a small 4 to 6 kilowatt system (roughly 60 to 80 linear feet of perimeter), expect to pay $600 to $950. A medium system in the 8 to 10 kilowatt range runs $1,100 to $1,700. Larger systems of 12 kilowatts or more start around $1,900 and can exceed $2,800. DIY kits with mesh and fasteners are available for a few hundred dollars, though working on a roof around live electrical equipment adds risk if you’re not experienced.
Getting Squirrels Out First
Installing a critter guard while squirrels are still nesting underneath is a mistake. Sealing animals inside can lead to dead wildlife on your roof, which creates odor problems and attracts insects. It can also cause panicked squirrels to do far more chewing damage trying to escape.
A wildlife exclusion professional will inspect the area under the panels for nesting material, droppings, chewed wiring, and entry points. If animals are actively present, they’re removed humanely before anything gets sealed. The timing matters: spring and early summer are peak nesting seasons, so if you’re scheduling preventive work, late fall or winter is easier because nests are less likely to contain offspring. That said, removal can happen any time of year with proper handling.
Once the area is clear, any damaged wiring should be repaired by a licensed solar installer before the critter guard goes on. This is the time to fix problems, not cover them up.
Repair Costs and Insurance Coverage
Squirrel damage to solar wiring is not covered by your solar panel manufacturer’s warranty. Warranties protect against equipment defects, not animal behavior. However, most homeowners insurance policies do cover critter and vermin damage to wiring. If a squirrel chews through your system’s cables, you can typically file a claim to cover the repair.
That said, filing repeated claims for the same preventable issue can affect your premiums. This is one reason critter guards pay for themselves relatively quickly. Replacing chewed DC wiring across multiple panels, plus the labor to safely access and repair a rooftop array, can easily cost more than the guard installation would have. Solar companies report that rodent and bird damage is one of the most common categories of solar insurance claims, so insurers view critter guard installation favorably.
Other Deterrent Options
Critter guards are the gold standard, but a few supplementary tactics can help if you’re dealing with persistent squirrels or aren’t ready for a full installation.
- Trim nearby trees. Squirrels access most roofs by jumping from overhanging branches. Cutting branches back at least 6 to 8 feet from the roof edge eliminates the easiest route.
- Conduit covers. If your installer left exposed wiring runs between panels, adding wire loom or rigid conduit over the cables protects against chewing even without a full perimeter guard.
- Predator decoys and repellents. Plastic owls and chemical repellents offer short-term deterrence at best. Squirrels habituate to stationary decoys within days, and spray repellents wash off in rain. These aren’t reliable long-term solutions.
The most effective approach combines tree trimming with a professionally installed critter guard. For a system that will be on your roof for 25 years, spending $1,000 to $2,000 on prevention is modest compared to the cost of repeated wiring repairs and lost energy production from panels sitting offline for weeks while you schedule service.