Once you’ve made an investment in a solar energy system, you’re probably going to be concerned about protecting that investment. The weather in Florida introduces many causes for concern, including hurricanes, tornadoes, hail and lightning (oh my!). One question we get fairly often is this: “Can my solar energy system be protected from lightning strikes?”
In the event of a direct hit? The short and most truthful answer to the above question is “No.” There is simply no way to protect any structure from such a devastating blast of current. But can you help to mitigate the risk to your home, electronics and solar array? Absolutely. Let us explain.
While direct lightning strikes are relatively rare, most damage occurs from nearby hits. Even a near-strike can induce thousands of volts onto the house and PV array wiring; the wiring in a house or PV system can act like an antenna and feed back thousands of volts into the inverter and other equipment if unprotected or ungrounded. The panels are not usually the biggest victim of lightning strikes, as frames and mounts on panels are usually grounded; the inverters and controllers are.
Proper grounding is essential for protecting your solar energy system against lightning strikes and damage. You can’t stop the strike but you can help give the voltage a direct path to the ground. Every system installed by Brilliant Harvest (or any other good solar contractor) by code must be equipped with an “equipment grounding conductor” (EGC), which provides a connection between all metal frames and equipment and ground. This EGC must connect to all exposed metallic components of the array and can act as a path for lightning. However, it is likely that if there was a direct hit, the lightning would damage the EGC and other metal components exposed to the strike. Since the metal panel frames and racking of the solar array are located on the roof, the EGC will direct a strike to the solar array to ground and may reduce additional damage to the building. However, there is no guarantee of this – it is important to note that the EGC is not intended to take the place of a dedicated lightning protection system.
Lightning protection systems, whose sole purpose is to safeguard buildings and their occupants, are available for homes and businesses. If lightning happens to hit a protected building directly, the system offers a good, safe path to ground for the lightning to follow. It is important to note that lightning protection systems do not attract lightning, do not and cannot prevent or dissipate lightning, and may not offer surge protection for valuable electronics (although surge arrestors can be installed and do offer protection). What lightning protections systems do is offer fire protection and structural damage protection by preventing the surge of electrical current from passing through building materials and, instead, directing voltage to the ground around the structure.
Without some kind of conductive pathway to reach the ground, a lightning strike can use any conductor available, including phone, cable or electrical lines, water or gas pipes, or even the structure itself if constructed of steel or other conductive metal. The components of a lightning protection system include rods (or air terminals), small, vertical protrusions that act as the “terminal” for a lightning discharge; conductor cables, which carry lightning current from the rods to the ground; and ground rods, which are buried into the earth around the protected structure and allow lightning current to discharge around the structure
Please note that lightning protection systems must be custom-designed for each structure – you should only consider a qualified contractor.
As for equipment that protects your electronics, surge arrestors (or surge protectors) can be applied to electrical systems to offer a discharge path to the earth, rather than allowing current to flow through your electronics and appliances. Surge arrestors – which can and should be used even with lightning protection systems in place – go across live wires and then, if the voltage goes above a certain level, they will shunt the higher voltage to ground. The surge capacitor takes things a step further, catching high voltage spikes on the AC line that are too fast for the surge arrestor to catch.
As we’ve said already, in the case of a direct strike – or even one that’s very close – there is no lightning protection system or device that can prevent severe damage to structures and the electronic devices within. Even disconnects that switch off power to a device or devices can’t guarantee protection: lightning bolts are able to jump air gaps with ease. (Of course, you should always try to remember to unplug the electronics you value when lightning is present – that’s your one sure-fire way to guarantee they will survive a storm.)
We find that most people will not fully appreciate the danger and cost of lightning damage until it happens to them. It is always best to have some level of structural and equipment protection in place, especially in a location as prone to lightning strikes as our region of Florida. But in a direct lightning strike, the current will distribute itself across all available paths to the ground and do significant damage along the way. So make sure your homeowner’s insurance policy covers lightning damage and take every step to ensure you and your loved ones are sheltered and secure as soon as you hear that first rumble of thunder in the distance.
Find a detailed explanation about lightning protection here. As always, if you have any questions, please do not hesitate to give us a call!