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What’s The Difference Between A Good And A Bad Solar Installation?

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What’s The Difference Between A Good And A Bad Solar Installation?

So you have been looking at getting solar installed at your home or business?
What a great idea!
Save money and save the environment at the same time, you can’t really go wrong hey?

Well, not exactly. 5 minutes on the internet or talking to solar installers on the phone and you’ll realise it’s shark tank out there. You’ll find an entry level 6.6kw solar system going from anywhere to $2000 – 10,000 depending on the solar retailer. You’ll even hear some offering “zero dollars upfront” but what does that even mean?

I hear horror stories on a weekly basis of innocent people who have either been ripped off by a shonky salesman or left with a leaky roof, high interest finance and low performing solar systems installed by cowboy solar installers. If you don’t believe me search “crap solar” on Facebook and see what comes up.

With so many solar suppliers, different products, high pressure salesman and dodgy solar installers, how can you possibly know who to trust?

Sure, you could apply to another “3 quotes” style site that will sell your details to the highest bidder but that will just mean you’re being harassed 24 hours a day by telemarketers selling a product you probably don’t want.
You don’t have time for that.

Like any purchase, the more research you do in advanced the better equiped you will be to make a great purchase at a fair price. 

I say fair because the cheapest is usually far from the best, with thousands of solar companies going bankrupt in the last 10 years in Australia, you’re going to need to find someone you trust to do a quality solar installation that will last 25 years+ on your roof .

The first thing to do would be check their reviews, If you know anyone that has had solar installed by them even better. Next I would be checking the photos of their work online. Great solar installers are extremely proud of their work and love any excuse to get the drone out! A lack of photos of recent work online might be a red flag. Once you have access to some evidence of their work.
These are the things you should be looking for!

Table Of Contents

What Makes Up A Dodgy Solar Installation Anyway?

In this blog I have outlined some of the most common solar installation defects that I have seen in my recent years as the lead installer at Lightning Solar.

Some may not be visible to the eye, even if you’re the type of person to get the ladder out and check…

However, if you start to notice one or two (usually where there is smoke there is fire 😆) you can probably bet there is more defects than you know. If this is your installation and you see some of the below insist on getting an independent electrical inspector out to make sure everything is 100% compliant with all codes.

Solar Panels Shaded During Peak Sun Hours

Although solar panels have come a long way in recent years, they still struggle with shade. Most string solar inverters operate from 2 strings of panels, let’s say 10 and 10 for argument sake, If 1 of the panels on that string of 10 is affected by shade, then the other 9 will suffer severely reduced solar production. 

Luckily there are many great systems that use DC power optimisers or micro-inverters to bypass shade affected panels, this will mitigate the losses from shading. However, as a general rule, it is best to make sure the solar panels have as much sun as possible during the day. Make sure your CEC accredited designer allows for any shading issues.

Solar Panel Clamping Zones And Clearances

Solar panels with clamps more than 25% down the panel become a hazard of flapping around in the wind. This causes unnecessary stress on the panels, your roof, can create noise and definitely voids your warranty, whoops! This is particularly common on tin roofs, as instead of having hundreds of tiles to mount brackets too, the CEC accredited installers are limited by the existing screw lines. Make sure you check this one straight away after your solar installers are finished and ask them about it if anything doesn’t look right.

Solar DC Isolator Top Entry

This one used to be “kinda okay…” until a bunch of houses burnt down, now it’s a big no no. Solar DC Isolators are enough of a hazard up there for decades in the Australian elements, unlike AC circuit breakers they don’t cut out in the event of a short circuit. This means if water gets inside they will burn and won’t stop until the sun goes down. I have seen some crazy fires online due to this and have to say it is one of the scariest things that could happen to your home. For this reason all cable and conduit entries used must be at the bottom of the isolator to prevent water getting in.

Solar Inverter In Direct Sunlight

Solar inverters aren’t designed to cope with the harsh Australian sun for hours on end. An hour or two probably won’t hurt in the morning or late afternoon. But if your inverter is coping direct sunlight for several hours or more a day, it probably won’t even last 5 years and you can forget about that 10 year warranty you purchased from the European inverter manufacturer as the inverter wasn’t “installed to manufacturer specs” If the only position for the inverter is on a north wall. Make sure your installers put an awning above it to provide shade.

Roof Penetrations For Solar DC Cables

Stained ceiling anyone?
Floorboards flooder with water seeping through your downlights anyone?
No, I didn’t think so.
This one of the most important parts of a solar installation, if not done properly, your roof will DEFINITELY leak, it’s the main point of failure with a solar installation. The scariest part about this? For some reason it’s usually the lowest paid apprentice or labour trusted with “siliconing the dektights” on site. Before you installer or electrical inspector leaves, ask him to “double check the dektights”.

Cables Hanging On The Roof

All cables should be clipped up under the solar panels and not left dangling on the roof, it’s just a rule. Sure, I have been to heaps of old systems where this hasn’t been done and those houses haven’t caught on fire (yet) but It’s definitely a thing, if nothing else it will show you if your solar installers actually have attention to detail or are rough as guts.

Tiles Broken By Installers

Solar panels are heavy and can be awkward, if you have a tile roof your installers will need to take care when laying panels, I would say there is a 95% chance at least 1 tile will be broken, so have your spares ready for the workers and make sure they know if you plan to get solar installed at your home! Sometimes an electrical apprentice or solar roofer might be too lazy to drive 15 mins to a roofing supplies store and just silicone the tiles. While arguably silicon will work to seal your roof when applied correctly, It should only ever be a last resort when no new tiles are available.

Mismatched MC4 Plugs

According to Solar Victoria, mismatched MC4 plugs from non compatible brands between solar panels and DC isolators are the most common defect on all solar installations in Victoria. A common shortcut installers will take when there is no more of the same MC4 plugs in the van on the day of solar installation.

Solar DC Conduit Not Secured In The Roof

Since Solar DC cabling is technically a generator supply and has no circuit protection on the solar side. Solar DC cabling needs to be secured safely in your roof and not a potential death trap for any other tradie who works on your home.

Tiles Not Ground Flush

This is another thing not many solar installers cared about until Solar Victoria and the CEC ramped up the audits in recent years. Now tiles must be ground down above the tile brackets to stop wind and water getting into your ingress to your roof space. It is also much less likely the installers will stand above a bracket and crack tiles while laying panels when they have been ground, so it’s just good practice!


In conclusion, when you see solar retailers advertise outrageously cheap prices, keep in mind they all pretty much pay the same price for equipment, the only real place they can cut costs is with installation. So make sure you do your research and only sign a contract with a quality solar installer. Beware of any solar “bidding” sites as they put pressure on installers to cut corners on unsustainable margins, it’s likely those installers won’t be around in 12 months if you have a warranty issues.

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Written By:

Luke Cove
Managing Director
Lightning Solar & Electrical

1 thought on “What’s The Difference Between A Good And A Bad Solar Installation?”

  1. Hi Luke, Interesting information: please send me photos of how you do it differently: your roof penetrations, ground flush tiles, DC conduit secured in the roof, matched MC4 plugs. I do have a shading issue but will chat with Ben about that. What brand of raking do you use?
    Thanks, John

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