If you are familiar with electrical systems, ‘grounding’ is a common term you may be familiar with. So it is natural to question, do solar panels need to be grounded?
According to the NEC (National Electric Code) in the USA all PV Systems above 50V must have one current-carrying conductor connected to the ground/earth. With that, all exposed metal parts of the system must be grounded regardless of voltage. Thus grounding/earthing is a must for Solar Panel Safety.
If you are talking about very small-scale solar panels like on DIY Scale you probably don’t need grounding. However in the case of a solar system powering your home or a huge solar farm, earthing is a must according to the Safety standard of your country.
Anyway, aside from the regulations, Solar Panel grounding can prevent disaster and various accidents as it leads extra current straight into the earth. That’s why it is highly recommended that you hire an electrician to do the grounding for you if you are inexperienced. Regardless, knowledge regarding Grounding is extremely important if you want safety.
In the following article, we will discuss types of grounding, benefits of grounding, when you should ground your panel, requirements for grounding, and more.
Table of Contents
What is Solar Panel Grounding?
You may already know that Earthing is somewhat of a safety mechanism. However, there is more to it. As the saying goes: ‘Electricity follows the path of least resistance, you don’t want high voltage current to go somewhere else and knock out your solar installation. So you provide it a good path toward earth. That right there is the gist of earthing.
Let’s take the sink in your bathtub. It’s very important as it drains extra water, right? Earthing is the equivalent of sinks in Solar or any other electrical system. Let’s say you have an extra surge of power in your system. Earthing sends it right into Earth (as the name suggests) and prevents electrical disaster.
The Earth can safely absorb excess electricity. And thus the extra electricity doesn’t ruin your circuits or fry up any other electrical equipment.
When Do You Need Grounding For Solar Panels?
Your average small voltage solar panels used for science projects don’t require grounding. What does require grounding though is a whole PV system or a Solar Farm. But first thing first, check your country or city’s electrical regulation, ask experts in your city about Electrical Regulation.
According to the National Electric Code (NEC), if your Solar Panel system exceeds 50 Volt, grounding is a must. And metal parts of solar panels like conduits, racking, and other enclosures must be grounded regardless of that. This is for the USA. For other countries, the requirements may differ.
Another important thing to keep in mind is Solar Panels are generally double isolated. What needs earthing most of the time is the metal rack it is mounted upon. The panel itself may not need earthing except special circumstances:
1. The Panel is very close to a lightning conductor system.
2. The Inverter has no transformer.
In general, it is highly recommended that you ground your Solar Installations PV System. And don’t forget all the equipment connected to it. Things like Inverters, Solar Charge Controllers, and other things connected to the system also need to be grounded.
Why Should You Ground Your Solar Panel?
Now that you know when you should ground a solar panel you may have a slight idea of why you should do it. The most important reason is the safety of course. But other than that will have various benefits for grounding your solar system. Below we discuss all the benefits.
Lightning Won’t Destroy Your Panel
Let’s say Thor decides to send lighting into your panel. (Not literally of course). Don’t forget that your panel is metallic and lighting can decide to descend upon it.
Once it hits your panel your precious inverter and charge controller would be fried. And there goes your money. But if you have grounded your system everything will be alright.
No Shock by Electricity
Nobody likes to get shocked while doing electrical work. Let’s say you or someone else decides to work on the wiring. If you ain’t got grounding, shock is coming your way.
The grounding connection triggers any breaker to stop excess electricity from frying you to death. The accidental currents return to mother earth instead of killing you.
Remember how the physics teacher in high school used to say Short-Circuit is bad. Well if you don’t ground your panel you’ll see why?
Electricity can convert to heat energy and that’s why if a short circuit happens in your panel it will catch on fire fast. Now if you have your panel grounded breaker will trigger and the current would go to mother earth.
And bingo, you saved yourself from calling the fire department.
Static Electricity Discharge
This one is to improve the performance of your panel. Your panels collect static electric charges on the exposed surface. Now, this thing will interact with the semiconductor.
Do you see where this is going? Grounding will send the charge to earth and save you unwanted problems regarding the static electricity build-up.
Types of Grounding in Solar Panel
There are mainly two types of grounding when we are thinking about PV Systems and Solar Panel. Both of them are discussed in detail below:
This is a more traditional form of grounding. In the United States, the method goes like this: All non-current carrying exposed metal parts are merged (electrically connected) and eventually connected to the earth. This way various electrical hazards are prevented.
If you bond the exposed metal surface to the earth the potential difference between earth and conductive surface in the time of a fault connection becomes nearly zero. Thus Electric Shock is prevented.
In this method, you ground one of the two conductors coming out of the PV system. Generally, it’s the negative wire that is to be grounded.
All conductor wires used in this method are generally white-colored. And these wires need to be bonded to the ground inside the inverter. But there is still the risk of fire from excessive current flow. That’s why you need to include a ground fault fuse to prevent fire.
Equipment You Need to Ground a Solar Panel
Every component of a Solar Panel Grounding system is important. From Grounding Electrode to Conductors, each needs to be properly selected. Also, one crucial thing to remember is that your PV Grounding System components need to follow the guidelines of NEC if you are in the USA.
Below we will discuss the most common components you need for a grounding system that follows Article 100 of the National Electric Code (NEC):
This is basically a ground rod that you bury in the soil. You can also use a metal water pipe, ground ring, UFER grounding method, etc. which complies with Article 250.52 if you are in the USA or your country’s electric guidelines.
So what does this do? In layman’s terms, it is a conducting object that creates a direct connection to the earth with the electric system.
GEC: Grounding Electrode Conductor
As the name suggests, this is a simple conductor you will use to connect the System Grounded Conductor and the Grounding Electrode. A real-world example is a typical wire.
The size of the wire depends on the potential fault current (Current that happens when the system goes haywire). AC and DC components both have different requirements. But a single conductor can meet both of them. (See 690.47 of NEC)
EGC: Equipment Grounding Conductor
Same as before but this time you connect non-current carrying metal parts of the system with the Grounding electrode. You use the same specification as the former (GEC).
Both GEC and the EGC must follow the NEC Guideline. The conductor should be made out of bare copper. Green insulated conductors with or without yellow stripping can also be used.
Aside from the equipment mentioned previously, you must ensure all other grounding equipment meets the safety guidelines of NEC or your country’s rules. An experienced electrician can easily do that for you.
Important Things Keep in Mind during Solar Panel Grounding
Before you begin the installation of a grounding system you should know some info that will help you in the long run. A more detailed explanation is given below.
As its name suggests, this is indeed a problem regarding the system. So what is it? In simple words, it is an accidental short circuit. Usually, this happens with one or more current-carrying conductors.
Do not ignore this problem. This can generate DC arcs at the fault point on the ground fault path. If you don’t hire a professional to fix this immediately the DC arcs may start a fire show.
As said before the exposed metal parts need to be grounded. By rule, you also need to ground the aluminum module frame. You can easily use a tin-plated lay-in lug to do this.
Enclosure and Conduit Grounding:
The metal enclosure is like a box. Both this and the conduits contain energized conductors. Follow the manufacturer’s instructions to ground these properly.
Generally, route the EGC or GEC through some ‘lay in’ type connection. This will make the grounding conductor maintain its continuity. See NEC Article 250 for more info regarding this
Array Grounding Conductor Installation:
If you have a solar array then the grounding conduction that runs through the array usually acts as both EGC and the DC GEC. For installation requirements see 690.47 (C) of NEC.
Generally, you can use a #8 (Eight Gauge) copper. But conductor size depends on the size of the system. And in that case, you have to increase it via irreversible means. For Example, copper crimp splice.
Seek Help From Expert
If you are new to all of this, I highly suggest that you seek help from experienced electricians. They know NEC and other requirements very well and will easily ground your panel for you.
Along with that an Expert can identify critical problems and solve them thus saving you the hassle you need to face if you are not feeling confident in doing this.
Being knowledgeable about grounding your solar panel can help you save your system in the long run. Just like in the USA, each country has its own regulation. So follow those and ground your solar system.
Grounding or earthing your solar panel can save you from various hassles such as Electric Shock, Fire Hazard, Lightning strike, etc. Remember safety above all. So do not ignore the grounding of a solar panel and get it done as soon as possible. Anyway, hopefully, the above knowledge can help you in the long run.