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Squirrels, birds, and raccoons love nesting under solar panels. Learn how critter guards protect your system and why they should be part of every Colorado installation.

Solar panels create an ideal shelter for wildlife. The gap between your panels and roof surface offers protection from wind, rain, snow, and predators — making it prime real estate for squirrels, birds, raccoons, and other critters common along Colorado's Front Range. While a squirrel nesting under your panels might seem harmless, the damage wildlife can cause to your solar system ranges from annoying to catastrophic.

Critter guards are a simple, cost-effective solution that prevents animals from accessing the space beneath your panels. At ProGreen Solar, we recommend critter guards on virtually every residential installation in Colorado, and here is why.

Why Wildlife Is Attracted to Solar Panels

Solar panels are typically mounted three to eight inches above the roof surface on a racking system. This creates a sheltered cavity that stays dry during rain and snow, stays warmer than exposed areas in winter, and provides shade in summer. For Colorado wildlife, this is an upgrade over nearly any natural shelter available.

Squirrels

Fox squirrels and Abert's squirrels are the most common solar panel invaders along the Front Range. They are active year-round and are persistent chewers. Squirrels do not just nest under panels — they chew on wiring, insulation, and even the panel frames themselves. A squirrel can chew through the protective jacket on a DC wire in minutes, exposing live conductors that carry 300 to 600 volts.

Birds

Pigeons, starlings, house sparrows, and even magpies build nests under solar panels. Bird nests can be large — pigeon nests in particular accumulate quickly and can fill the entire gap between a panel and the roof. Nesting material restricts airflow (reducing panel cooling and performance), retains moisture against the roof surface, and attracts mites and other pests. In Colorado's dry climate, accumulated nesting material also creates a fire hazard.

Raccoons

Raccoons are strong enough to pull at wiring and conduit connections. While less common than squirrels or birds, raccoons occasionally access roof-mounted solar systems, especially on single-story homes near trees. Their size and strength mean they can displace panels, damage racking, and tear apart wiring harnesses in ways that smaller animals cannot.

Other Wildlife

Mice, rats, chipmunks, and even snakes have been found under solar arrays in Colorado. Mice are especially problematic because they can fit through very small gaps and, like squirrels, will chew on wiring.

The Damage Wildlife Causes to Solar Systems

Wildlife damage to solar systems is one of the most common solar panel problems we see in Colorado, and it ranges from cosmetic to system-threatening.

Chewed Wiring

This is the most serious risk. Solar DC wiring carries high voltage whenever the sun is shining, and there is no way to turn it off at the panel level (even with rapid shutdown, the conductors between each panel and its shutdown device remain energized). A chewed wire can cause:

• Arc faults — electrical arcing between exposed conductors or from a conductor to the grounded frame, which can ignite roofing material
• Ground faults — current leaking to ground through the damaged insulation, which triggers a system shutdown and requires professional repair
• Production loss — a severed conductor takes an entire string of panels offline
• Expensive repairs — rewiring under a solar array typically costs $500 to $2,000 depending on the extent of the damage and the number of panels that need to be removed for access

Nesting Debris

Accumulated nesting material creates several problems. It traps moisture against the roof surface, which can accelerate shingle degradation and lead to leaks. It restricts airflow beneath the panels, causing them to run hotter and produce less energy. It also blocks water drainage paths, causing pooling that stresses roof materials. In extreme cases, nesting debris can even cause hot spots on the panel backsheet by pressing insulating material directly against it.

Roof Damage

Animals accessing the space under panels scratch and tear at shingles, flashing, and sealant around mounting points. Over years, this repeated physical damage compromises the roof's waterproofing layer. Fixing roof damage under solar panels requires a partial or full panel removal, which is expensive and time-consuming.

What Are Critter Guards?

Critter guards (also called pest barriers, bird guards, or solar panel skirts) are physical barriers installed around the perimeter of your solar array that block animals from accessing the space beneath the panels. They close off the gap between the bottom edge of the panels and the roof surface while still allowing adequate airflow for panel cooling.

Galvanized Steel Mesh Guards

The most common and effective type. These use heavy-gauge galvanized steel wire mesh (typically with half-inch openings) that is shaped to fit the panel profile and attached to the panel frames with stainless steel fastener clips. Galvanized mesh resists corrosion, withstands Colorado's UV exposure, and is strong enough to prevent squirrels and raccoons from pushing through or chewing through it. When properly installed, galvanized mesh guards last the life of the solar system.

Aluminum Mesh Guards

Lighter weight and easier to work with than galvanized steel. Aluminum mesh is corrosion-resistant and looks cleaner from the ground. However, it is softer than steel, and determined squirrels have been known to chew through thin aluminum mesh over time. Higher-gauge aluminum mesh (thicker wire) addresses this issue but costs more.

Clip-On Plastic Guards

A budget option that clips directly onto panel frames without tools. Plastic guards are the easiest to install but offer the least long-term durability. Colorado's intense UV exposure and temperature swings (from well below zero to 100-plus degrees Fahrenheit) cause most plastic guards to become brittle and crack within a few years. We generally do not recommend plastic guards for Colorado installations.

How Critter Guards Are Installed

Professional critter guard installation is straightforward but requires roof access and attention to detail. Here is what the process looks like when ProGreen installs critter guards.

• Inspection and cleanup: Before installing guards, we inspect the area under your panels and remove any existing nests, debris, droppings, or deceased animals. Starting with a clean slate is essential.
• Wiring inspection: While the underside is accessible, we check all visible wiring for signs of chew damage, abrasion, or degraded insulation. Any damaged wiring is repaired before guards go on.
• Mesh cutting and shaping: The mesh is measured and cut to match the exact perimeter of your array. Corners and edges are shaped to fit tightly against panel frames and roof surfaces without gaps larger than half an inch.
• Attachment: The mesh is secured to the panel frames using stainless steel spring clips or specialized fasteners that grip the frame without penetrating it. No holes are drilled in the panels. The mesh bottom edge sits against the roof surface without being screwed into the roof, which avoids creating new penetrations.
• Final check: Every edge is inspected for gaps, loose sections, or sharp edges that could injure an animal or catch wind.

The entire process typically takes two to four hours for a standard residential system of 20 to 30 panels. No panels need to be removed, and the system continues producing energy during installation.

How Much Do Critter Guards Cost?

Critter guard costs vary based on system size, roof access difficulty, guard material, and whether cleanup of existing wildlife damage is needed. Here are typical price ranges for Colorado installations.

• Materials only (DIY): $150 to $400 for a typical residential system, depending on mesh quality
• Professional installation: $800 to $2,500 total (materials plus labor) for most residential systems
• Installed with new solar system: $500 to $1,500 when added to a new installation (lower cost because the crew is already on the roof with equipment)

Compare that to the cost of a single critter damage repair — $500 to $2,000 or more — and critter guards pay for themselves the first time they prevent an incident. Most homeowners consider them inexpensive insurance for a system that will be on their roof for 25 to 35 years.

Why ProGreen Recommends Critter Guards for Every Installation

Colorado's Front Range has an unusually dense population of tree squirrels, especially in established neighborhoods in Longmont, Boulder, Fort Collins, Denver, and surrounding communities. The combination of mature trees (providing roof access) and urban wildlife adaptation makes critter damage significantly more common here than in many other regions.

In our experience since 2020, roughly one in five solar systems without critter guards in Front Range neighborhoods will experience some form of wildlife interference within the first five years. The damage is not always catastrophic — sometimes it is just bird droppings accumulating on panels or minor nesting under one section — but when squirrels chew through DC wiring, the repair bill and lost production time are significant.

We recommend installing critter guards at the time of your solar installation whenever possible. Adding them during the initial install costs less because the crew, equipment, and roof access are already in place. Retrofitting guards later requires a separate service visit and is typically 30 to 50 percent more expensive than including them upfront.

Signs You Already Have a Critter Problem

If your solar system was installed without critter guards, watch for these indicators that wildlife has moved in.

• Scratching or scurrying sounds on the roof, especially in early morning or late evening
• Visible nesting material — sticks, leaves, grass, or insulation poking out from under panel edges
• Droppings on or around panels, visible from the ground with binoculars
• Unexplained production drops in your monitoring system, which could indicate shading from debris or a wiring issue
• Inverter error codes related to ground faults or arc faults, which can be caused by damaged wiring
• Squirrels on your roof more frequently than before panels were installed

If you notice any of these signs, do not wait. Contact a solar professional to inspect the array, clean out any wildlife activity, repair any damage, and install critter guards before the problem gets worse.

DIY vs. Professional Installation

Critter guard kits are available online and at home improvement stores, and some homeowners choose to install them themselves. This can work, but there are important considerations.

• Roof safety: Working on a roof is inherently dangerous. Sloped roofs, especially when wet or icy, require proper fall protection equipment. Most homeowners do not have harnesses and anchor points.
• Electrical hazard: The wiring under your solar panels is live whenever the sun is shining. Accidentally contacting or damaging a conductor can cause serious shock or arc flash. Professionals know how to work safely around energized solar wiring.
• Warranty concerns: Improper installation of critter guards — especially if you inadvertently damage panel frames, wiring, or mounting hardware — can void your manufacturer warranty or workmanship warranty.
• Quality of seal: The effectiveness of critter guards depends entirely on eliminating gaps. Even a two-inch gap is enough for a mouse to enter. Professional installers have the experience and materials to achieve a complete seal.

For most homeowners, professional installation is the better choice. The cost difference between DIY and professional is typically $400 to $800, which is modest relative to the risk of personal injury or system damage.

Protect Your Solar Investment from Colorado Wildlife

Your solar system is a 25-to-35-year investment. Critter guards are a small, one-time expense that protects that investment from one of the most common and preventable sources of damage in Colorado. Whether you are planning a new installation or have an existing system that needs protection, critter guards should be part of the conversation.

If you are ready to add critter guards to your system — or if you are planning a new solar installation and want them included from day one — call ProGreen Solar at (303) 484-1410. We will inspect your system, recommend the right guard solution, and get your panels protected.

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