How to Ground Solar Panels the Right Way…
Nowadays, going off-grid has already become a normal thing to do, especially inremote cabins and cottages. Arguably, one of the popular ways of producing electricity for home use is installing a solar panel system. While it provides an endless source of renewable energy, it’s an ideal way of reducing costs. Perhaps, you’ve already bought one for your house. Still, you need to ground your solar arrays and equipment before you start using your system.
There are plenty of reasons to ground your solar panels, but the most obvious one is safety. Indeed, lightning storms are the most common cause of electrical failures, especially if you live in the countryside. Just like your home outlets, all your solar equipment requires proper grounding. Therefore, it’s imperative to take the precaution to direct any surges to a safer path. That way, you’ll prevent possible failures and damages to your inverters, mounting, controllers, or any other part of your system.
Follow this article to learn more about how to ground your solar panels correctly:
How do solar panel system operate?
Before you do anything, you must be well aware of how solar panels operate. Firstly, solar panels consist of several individual solar cells. They consist of different silicon, phosphorous, and boron levels, respectively, which provide the negative and positive charge. In essence, the solar panel initiates an electric current by absorbing photons. Consequently, the entire process, known as the Photovoltaic Effect, results in pulling free electrons into a DC.
Typically, a well-balanced solar panel configuration generates power during the day. In turn, homeowners can use the stored energy at night. Thanks to the net metering programs, you can sell the excess electricity, but you can keep it, too. If you live off-grid, you may use a battery bank, charge controller, and an inverter to store energy.
Usually, the array sends a direct current to the battery bank. The inverter then converts the direct current into alternating current, which you can use for your appliances. That way, solar panel systems can meet even the most demanding load requirements. As a result, you can use the AC current to power both houses and commercial buildings. Moreover, you can apply this method to trailers, boats, remote cabins, cottages, and many more.
What are the benefits of solar panels?
As you can imagine, the benefits of using solar panels are many. Thanks to the advancements in technology, solar panels have greatly improved in terms of efficiency. Now, they represent a practical way to produce renewable energy.
Since they don’t require connection to the primary electric utility grid, they’re an ideal source of energy for off-grid living. What’s more, such systems are no longer expensive to install. You don’t have to pay enormous fees for utility poles and cabling to the nearest main grid access point either.
Arguably, one of the most significant benefits of solar panels is that they provide clean and renewable energy. In times of global climate change, reducing greenhouse gas emissions should be of great importance. Since solar panels have no moving parts, they require little maintenance.
Finally, if you take care of your solar panels properly, they can last for decades. Once you pay for the initial installation, such a system will produce electricity for the remainder of its lifespan. Furthermore, the owner can earn additional money by selling excess power to the local electric company.
Things to consider before you start grounding your solar panels
As expected, grounding a solar PV array isn’t for everyone. In this aspect, there are some requirements you need to meet first. Otherwise, you risk failing the first inspection.
Read your permit plans
First, you should start by reading your permit plans. Typically, they outline the city or county requirements that a solar panel system must meet. If you follow those rules, you’ll have no problem with the initial inspection.
Also, there are some notes regarding the process of grounding. They’re crucial for the approval of your system, so you must ensure you follow them strictly. If you ever feel you need help, you should ask the authors of these for assistance.
Be aware of the grounding requirements
Next, you should make sure you’re well aware of all grounding requirements for your equipment. Usually, you have to ground all non-current-carrying metal parts. In other words, any piece of metal that doesn’t have electricity flowing through it must be grounded. This includes racking, metal frames, metal conduits, the metal enclosures of your inverter, and many other components.
Follow the instructions in the manual
Luckily, you won’t have to create an entirely unique grounding system. Most racking companies have already designed their arrays to provide easy grounding. You’ll be happy to find out that your configuration requires you to ground one rail in each row. That way, you’ll provide grounding for all panel frames in a row, thanks to the integrated system.
In some cases, you may have to ground only one piece of the racking. This rail-less system needs just a few jumpers to keep the ground continuous through the entire array. Such an integrated system may include microinverters or DC optimizers. That’s why you must read the installation manual for your racking system first.
Follow the grounding instructions and remember to only use parts that are specific for your configuration. In case you have trouble understanding the instructions, don’t forget to call your racking company or retailer for clarification.
What are the different methods of grounding and bonding?
Before you start grounding and bonding your PV arrays, you should first learn about the possible methods to do that. Arguably, the two most popular ones are using approved mechanical connectors and bonding washers. The first one allows mounting mechanical connectors to a module or a racking frame using lay-in features. On the other hand, bonding washers serve the same purpose using hold-down clamps and bolted joints on the racking system. Either way, the result is a solid bond between metal parts.
Grounding and bonding solar panels the right way
As you may already know, the National Electrical Code (NEC) requires homeowners to bond all electrically conductive materials in solar panel systems. In other words, you must establish an effective ground-fault current path before you start using your solar PV array. You can do this by attaching the EGC that’s already on your roof to the panel racking. Consequently, you should run the EGC down through the conduit and all equipment enclosures. The connection must end in your main service panel and your central grounding system.
Since your conductor goes through the metal conduit, you must attach it to the grounding lugs at both ends of each line. Of course, you can try to get away with one-end grounding. However, you risk doing a lot of extra work to fix everything if the inspector scrutinizes you. In other words, it’s best to save yourself the headache and do connect the grounding lugs the right way. Don’t forget to also attach the EGC to lugs or grounding busbars to all metal parts of your equipment. If you decide to install a lug or busbar yourself, make sure you provide a decent path to the ground for the lug. You can do this easily by scraping the paint off its enclosure.
Last but not least, land the EGC at the grounding busbar. Alternatively, it’s a good idea to extend it to the actual ground rod. You can also connect it to your Ufer if you have access to it. Typically, you can find this concrete-encased grounding electrode inside your home’s wall. But if you can’t find it, bond the conductor that runs from the main service busbar to that ground rod.
Factors that may make grounding and bonding difficult
Without a doubt, grounding a PV system can go wrong in lots of ways. One of the factors to make the process difficult is the exposure to the elements. In turn, this can result in atypical situations where you may have to use methods different than the standard ones.
Unsuitable grounding lugs
For instance, the majority of grounding lugs aren’t suitable for outdoor installation. That way, the chance of premature failure in the intended path for fault current becomes much higher. Ultimately, you risk hampering the functionality of overcurrent and your ground-fault protection units.
Another factor that may impede the process of grounding is the expansion and contraction of the different materials. The steel, aluminum, copper, and PVC parts in your system continuously withstand the thermal cycling. This often causes some of them to loosen even after a proper installation. Indeed, no one is safe from such cases. After all, the system needs adequate connections and hardware as well as a corrosion-free surface.
Interactions of dissimilar metals
Last but not least, let’s not forget about cases where dissimilar metals may interact. As you can imagine, racking structures, module frames, and grounding devices use different metals. When there’s moisture, these interactions can lead to unwanted corrosion and failure.
The risks of not grounding your solar PV array
Typically, the process of bonding involves connecting your equipment to an equipment grounding conductor (EGC). In turn, it bonds to an overall grounding electrode system. Ultimately, you want to take all metal parts in your system and connect them together, so they become one piece. That way, you’ll easily connect them back to the source of power by EGCs. As a result, you’ll prevent a wide range of possible risks and dangers.
For example, you may have a case where there’s damaged insulation on a circuit wire. When the current-carrying conductor makes contact with a frame or rail, the latter gains potential voltage. In turn, the voltage is relative to any pole in the DC circuit that doesn’t show fault. As a result, it may carry current even during system operation, which may pose fire or shock hazard.
For this reason, you must carry out equipment grounding regardless of your PV system’s voltage. That way, you’ll limit the voltage that lightning, line surges, or unintentional contacts with higher-voltage lines can impose. What’s more, proper bonding and grounding will determine the voltage-to-ground that can hit non-current-carrying components of your array.
Conclusion for Grounding Solar Panels
Needless to say, solar panel systems are a must-have for cabins, cottages, trailers, and many more. While they use electricity from conventional sources obsolete, you need proper grounding to make them safe. That way, you’ll ensure the safety not only of your PV array but of your home as well. Hopefully, this guide is comprehensive enough to take you through the steps of grounding and bonding your system correctly. All you need is a little knowledge in the field and some patience. If you succeed, chances are high that you’ll no longer have to pay for electricity again!