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Is getting your panels inspected worth the expense? In the end, it comes down to how safe you really consider your rooftop solar to be.

How Safe is Rooftop Solar?

If you ever drive or ride in a car of your own free will, then it probably makes sense for you to consider rooftop solar safe.

Each year, the average Australian has about a 1 in 20,000 chance of dying in a car accident. But as far as I am aware, no one in Australia has ever died from a faulty solar system. Oh, sure, some installers may have fallen off roofs and some do-it-yourselfers may have managed to electrofry themselves, but I don’t believe anyone has ever died as the result of a fault in an installed system.

This is a pretty impressive result given the number of shonky installers Australia used to have (and, unfortunately, in some areas, still has).

At the start of this year around 17.2% of Australian households had rooftop solar1. This made for a grand total of over 1.6 million systems. On average, each home has had solar for 4.8 years, which comes to a total of over 7.7 million years without a fatality and that’s not bad.

Safety Issues To Consider

Unfortunately, rooftop solar is not perfectly safe. Anything with live current running through it can be dangerous if damaged or defective and solar systems are no exception. Fires have resulted from faults and, while most have been small, some have resulted in whole buildings being burned to bits.

While solar systems have no moving parts to wear out, problems that can potentially occur include:

Deterioration of cable insulation over time.

Failure of defective components.

Components filling with water.

Corrosion.

Animals chewing on cables.

Damage from natural disasters such as earthquakes, bush fires, and storms.

Damage from home renovations.

Incompetent installation.

DC isolator fires.

Having a professional inspect a system can result in problems being identified and rectified before they become a danger.

DC Solar Is Extremely Safe But AC Solar Is Safer

Most rooftop solar systems have a string inverter. This is basically a box that hangs on a wall and is connected to rooftop solar panels by one or more cables called strings. These cables send DC power from the panels to the inverter which changes it into the AC power homes use.

The drawback of string inverters is DC power isn’t as safe as AC power.

While any kind of electrical cabling can be dangerous if it becomes damaged, a DC cable is much more likely to arc than an AC cable. And I’m not talking about the good sort of ark that kills Nazis at the end of an Indiana Jones movie. I’m talking about the sort that can potentially burn your house down and which looks like this:

The danger of a DC arc occurring in a system that has a string inverter is the main safety reason why I would recommend ever having an inspection.

Rooftop DC Isolator Fires

Rooftop DC isolators are switches Australian Standards require to aid our brave fire fighters in their struggle against fire. Unfortunately, these fire-fighting devices have the rather horrible habit of starting fires themselves. Roofs are pretty harsh environments and if isolator switches aren’t built tough enough, they start to deteriorate from exposure to the elements until they become flaming dangerous.

While many of these fires have been confined to just the isolator or the area immediately around it, there have been some that have branched out to burn down entire houses. Isolator fires are particularly dangerous if the wind blows leaves and twigs from nearby trees onto the roof and they collect under the solar system and provide some convenient tinder to set the roof ablaze.

There have been both mandatory and voluntary recalls of DC isolators. Most were recalled before 2015, so if your system is reasonably new, the isolators are likely to be reliable, although it’s probably still not a good idea to trust them. Not all of the ones that are known to have problems have been replaced and this is something an installer can check when they inspect your system.

Microinverters Have A Safety Advantage

Microinverters are little inverters that are either built into solar panels or installed underneath them. Because they directly change the DC power produced by panels into the AC power homes use, there are no cables carrying DC power about the place and so far less a chance of the arc-angel of death popping round for a visit. There is also no need for rooftop DC isolator switches, with their nasty habit of immolating themselves.

While damaged AC cables are definitely still dangerous, they are much less dangerous than damaged DC cables. A solar system that uses microinverters is really no more deadly than any other electrical item in your home. And possibly less so, because there are no moving parts. They also have the advantage that they can usually be easily monitored online and if they fail, normally only the output of one panel will be lost.

Inspections: How Much And How Often?

The going rate for an inspection by an accredited solar installer is typically $200 to $300. For that money, they will check the connections, cables, panels, rooftop mounting, DC isolator switches, and inverter. Some offer to do extra tests for extra money as part of a premium service, but as far as safety is concerned, I don’t think the extra expense is worth the benefit.

I have been told by an installer the Clean Energy Council recommends an inspection every five years. However, an advertisement for rooftop solar inspections told me the Clean Energy Council recommends annual inspections.

Who to believe?

What the Clean Energy Council actually thinks, I don’t know. If they had a strong opinion, you would think they would have put it on their site somewhere, but I can’t see it.

What do I think? Well, if you’re going to get it done, I would suggest getting an inspection every five years.

So Do You Gamble And Forgo An Inspection Or Not?

Three particular circumstances in which I would recommend an inspection are:

When you’re moving into a new home that has a “mysterious” solar system.

When you suspect your system was installed by shonks.

When you live in an area where you’re required to have an anti-islanding test.

New Home Has Solar? Consider An Inspection.

When you move into a new home that has a solar system installed, the former owners might leave you a wealth of information about it or they may be able to tell you nothing. Some people don’t even know they have solar. If you end up the owner of a string inverter system that is full of mystery and potentially full of faults, then it could be a good idea to have it inspected because you can’t be certain what condition it is in or whether or not it was installed by shonks.

Think Your Installion Was Shonky? Consider An Inspection.

The best way to ensure your installers aren’t shonky is to use reliable installers in the first place.

But mistakes are made, snaky salespeople can be persuasive, and people fall for deals that seem too good to be true and which turn out to be exactly that. If you suspect shonks have done a shoddy job of installing your system, it may pay to have it inspected.

Anti-islanding Test Required? Ask About An Inspection

In Canberra and Victoria, solar households can be required by their network operator to have an anti-islanding test done every five years. This is designed to keep the grid and anyone who might be working on it during a blackout safe. But since you will have to pay for an accredited installer to come out anyway, you may as well see if you can have your solar system inspected at the same time.

[Update 22 February: As Steven Zilm has pointed out in the comments, according to SA Power Networks Small Embedded Generation Technical Guidelines 2013, rooftop solar systems have to be inspected and maintained at least every 5 years. The exact wording is from section 4.6 is:

“ensure that the small-embedded generating unit is inspected and maintained in accordance with the manufacturer’s instructions. If there are no applicable manufacturer’s instructions within at least 5 years after the date of installation and within 5 years after each previous inspection;”

And it goes on to say:

“ensure that the customer’s employees, servants or agents who carry out any electrical maintenance function on the small-embedded generation installation or any other part of the customer’s electrical equipment are appropriately qualified and licensed to perform such work.”

This means SA Power Networks could disconnect you from the grid if your rooftop system hasn’t been maintained within the past 5 years. Other network operators could have similar provisions hidden away in their technical guidelines.]

If You Want The Satisfaction…

If you are so inclined, and you have two or three hundred dollars to spare, you can afford to have your rooftop solar system serviced. When I say serviced, I’m not talking about a cursory check by someone so unskilled they’re unaware installing solar panels upside down is a bad idea. I am talking about a good service performed by a professional who will check out your system in detail to make sure everything is working properly, and above all, safely.

If, on the other hand, you don’t have the dollars to spare, take the main safety factor into account – inverters.

Microinverters have a safety advantage over string inverters. If you have a solar system that uses microinverters, doing without rooftop solar inspections is really no more dangerous than doing without inspections for other electrical devices in your home.

If, however, like the majority of solar households, you have a string inverter, then, regardless of how tightfisted you are, it is probably a good idea to have your system inspected about every five years.

Now it is quite possible someone reading this article will say,

“Hey, Ronald! You said no one in Australia has ever been killed by a faulty solar system, but you still recommend inspections every five years anyway. That makes no sense! Looking at the figures you gave, at a rough guess, paying for an inspection may only have around a one in two million chance of saving a life. This means if an inspection costs $250 then the cost of saving one life would be around $500 million. If I can instead save a life for around $4,400 by fighting malaria, it would be over 110,000 times more cost effective.”

Well, in response to that, I would say, “You’re right.”

Also, I would ask, “Are we related?” because you’re thinking like me and that’s always disturbing.

The fact is, when I came up with my recommendation to have solar systems inspected every five years, I was trying to think like a normal person. It wasn’t easy, but I persevered. Normal people seem to enjoy doing things that keep their families safe even when the cost/benefit ratio is ridiculously poor. They get a sense of satisfaction from it.

In truth, I don’t get that sense of satisfaction. And I’d say that’s probably the number one reason why I keep getting divorced. I’m fairly sure it’s not my smell.

Paying for rooftop solar inspections will help protect your property against fire, so it does have other advantages, but it’s not very cost effective and, unless you have a reason to suspect your solar system has a problem, you are not putting your family at any significant risk if you don’t have them done.

When it comes to saving human lives, you are probably better off paying to distribute mosquito nets, trading in your car for one with a higher safety rating, joining a gym, or paying someone to remove the crocodile from your living room.

But the final choice is down to you. If you want the sense of satisfaction that comes from knowing you’ve done something to keep your family safe, even if it is only a very small thing, then ensure your solar system is in good working order – have your system inspected.

Footnotes Around 17.2% of Australian had rooftop PV at the start of 2017. The percentage with solar PV or solar hot water is considerably higher, but I don’t have enough information at the moment to work out an exact figure. ↩