Residential Solar Panels, Solar Service
Written by Lisa Walsh

Diagnosing and Preventing Critter Damage to Solar Panel Arrays

Solar Service ,Home Solar Panels It’s no secret that hundreds of thousands of homes have installed roof mounted solar panels, with that number increasing with each passing day. The upward trend brings increasing problems that arise when tech meets nature. In an acorn shell we’re talking critters who nest, feed, chew and live their critter lives in and around solar panel installations.

Which Critters?

Any animal that can fit under your array poses a risk to a solar installation. Pigeons and other birds looking for a warm/safe place to build nests may do so under a solar array. This doesn’t usually cause any malfunction to the system. However, water build-up and bird waste may cause minor roof damage and may be more of a nuisance than anything.

Squirrels, mice and rats, on the other hand, can wreak havoc on a solar system. These members of the rodent-family have teeth that require filing down throughout the course of their lifetime. The wires, plastic connectors and small parts that run underneath the panels can be excellent teeth-filing equipment. We have seen squirrels chew the outer plastic covering of wires, as well as penetrate junction boxes on the back of panels and chew into the solar panel interiors. This type of damage will cause panels and even whole systems to cease power production.

Solar Service, Home Solar Panels ,Washington DC SolarWho’s at Risk?

Any solar system can be susceptible to critter damage. However, those most at risk are usually systems that are in wooded areas; particularly where tree branches extend close to the rooftops, allowing easy access for squirrels to make the jump from branch to solar system array. Although many homes and businesses fit this description, it’s also worth mentioning that for every critter complaint we’ve had – there are 20 or 30 more systems that have had NO issues with critters. However, it’s also worth mentioning that most of our customers are no more than 10 years into a 25 – 40-year solar system lifespan. Time will tell what the probability of critter-damage risk over a system’s lifetime will end up being.

Detecting and Diagnosing the Damage

Most solar system owners first become aware of a problem when their solar system does not seem to be producing as well as it used to. For homeowners with online monitoring, they may see that a string of panels – or individual panels (in the case of those systems outfitted with a microinverters or optimizers) are no longer registering power output. Others may hear scampering around on their roofs and may notice their utility bills creeping up. That’s when they call our service department. Our technicians need to remove and inspect each panel, as well as their connecting cables, suspected of damage. In most cases, we can remediate the wire damage onsite without engaging the solar panel manufacturer for a replacement panel. Whether this takes removal of every solar panel, or just a few – depends on the extent of the damage or ability to detect the extent of the damage.

Home Solar Panels,Solar Service, InstallationInstalling Critter Guard

There are a variety of anti-small-animal solutions out there for solar systems designed to create a barrier around the perimeter of the solar system. We usually choose the one most compatible with your solar system; depending on the type of racking initially installed. Most critter guards are made of some type of strong steel-mesh screen and they do not require drilling into the roof.

One of our more popular systems, the aptly named “Critter Guard” employs clips that attach to the bottom flange of the module frame and have hooks to snap the screen into place. The clips are painted steel and can be snapped to the appropriate length to accommodate height variations so there are no small spaces that accommodate a small animal. The mesh screen is vinyl-coated steel, rigid enough to keep out even the most industrious squirrel.

Residential Solar Panels ,Solar ServiceCritter Guard is now a standard option that we offer to our customers and we strongly encourage it when the structure has trees that are encroaching on the rooftop. While the tree branches may not be close enough today to make contact with the roof, over time, if not maintained, they can grow out to become that ideal path to an appealing new nesting site.

What are the costs involved?

The costs are always less if you can prevent the problem in the first place. Adding Critter Guard at the time of installation typically costs from $500 – $2000 depending on the size of your system; but of course this cost is integral to the solar system so most tax advisors would agree that the 30% tax credit would apply.

The costs for any rodent damage remediation will depend on the extent of the damage. Critter damage is not related to defects in installation covered under our standard Workmanship Warranty; neither will most solar panel/inverter manufacturers consider this damage a Material defect. Our service department charges Hourly-Time + Materials. These costs may range anywhere from $500 to $4000 for a mid-sized solar system including all remediation and installation of Critter guard to prevent further damage. We recommend inquiring with your home’s insurance agent to see if the costs can be covered under your homeowner’s insurance policy.

About Lisa Walsh

With over ten years in the solar industry, several of which have been in a core role with SES, Lisa’s role has developed into all aspects of originating, analyzing, and pre-qualifying prospective residential and commercial solar interests. This includes site feasibility studies, budgetary costs analysis, project financial planning and contract execution. Her role also extends into post-sale project management and oversight to insure a smooth, turnkey project.