Instyle Solar 5 Common Solar Mistakes To Make (And How To Avoid Them)

Whether you are a solar installer yourself or you are looking to hire someone to do it, knowing the basics will help you get the best results. Solar systems are a more common energy type so there are many (some say too many) installers around who can do the job and many ways the job can be done.

However, because solar systems are a long-term investment, the small decisions made during installation will have long-term effects, so it’s better to get it right the first time.
We are going to look at the top five mistakes you should avoid.

1. Getting Too Many Quotes

There are many ways to skin a cat and when it comes to the components of a solar system, there are two major factors that matter: cost and durability. There is a lot of competition in the solar installation industry and many installers feel under pressure to provide the absolute lowest price while compromising on quality.

Having many choices is a good thing because you can find exactly what you are looking for, but it also means there are many wrong answers.

Sometimes the offers can be sugar-coated for a quick sale. Make sure the products that you choose are distributed in Australia and would fall under Australian consumer law. The 25-year linear power guarantee of a minimum of 90% of rated power after 10 years is up to international standards. It is very careless to assume that if the price of one component is lower it is automatically of lower quality. Bargains do exist, but you have to make sure you are covered in the event something goes wrong.

Usually, buying sets of components from the same supplier is cheaper than buying them individually.

2. No Understanding of Solar System Economics

The whole point of using solar is to save money by no longer having to pay your local energy company. You can’t assume that because you are using solar, you are automatically going to gain in the long term—you have to get your calculations right first.

The payback period is the amount of time it will take to earn back the investment made on the solar system equipment and installation costs. If you add up all the energy generated by the solar system and multiply this by the cost of getting the same amount of electrical energy from the grid, you will find out how much money was saved. It is not that straightforward because the price of electricity changes depending on what time of day it is.

During peak time, the price is higher and this needs to be taken into consideration. Some less-experienced solar installers just have a general concept of how to put a system together and do not specifically have maximum cost reduction as an end goal.

The feed-in tariff scheme is central to the overall costs the customer will have to pay. When the solar system is connected to the grid, energy can be sent from the system to the grid.

The rate that is paid by the energy distributor varies and should be taken into consideration when deciding to connect to the grid. Feed-in tariffs paid in each state can be found here. Australia is in the process of moving from a fixed rate to a time-varying rate, which makes all solar calculations more complicated, but it’s not rocket science!

3. Wrong System Size

In our experience, the most common mistake made by installers is installing an oversized system. Some installers (who mean well, we assume) want to make sure the customer always has the energy they need to run their household or business.

The whole point of having batteries and connecting solar systems to the national electricity grid is to avoid oversizing.

If your solar panels are constantly generating too much energy, most of this will go to waste. The larger the solar panels are (in terms of power output, not physical size), the more they cost. There is no point in paying for power that you are never going to use, so energy stored in batteries and sometimes drawing energy from the grid can help reduce the system size.

As far as cost goes, storing energy in batteries is less efficient than using the energy immediately after it comes from the solar panels. Getting this delicate balance correct is what separates the good installers from the rest.

If connecting to the grid is an option, this makes things simpler because you can make a system that is large enough to meet the average demand for energy with the option of getting more later.

A typical mistake we have seen is assuming the system power rating is how much power output the system will regularly have. If a system is rated at 6kW, this is the peak power and the system will probably operate at half of this capacity most of the time.

4. Battery Discharge

The lifespan of your battery will depend on how that battery is used. You want to make sure the batteries do not regularly discharge beyond 50% of their capacity to make them last longer.

That being said, this is not always possible and many modern lithium-ion batteries discharge beyond 90%.

If you regularly charge the batteries using energy from the solar panels that they do not get to this point you can get more than ten years of operation from your batteries.

Batteries having to be changed too quickly is one of the main reasons people end up regretting switching to solar. This really sends the costs of the system way beyond what the customer had intended.

There are deep-cycle solar batteries out there that are specifically designed to avoid this, but even these will last longer if they are not almost fully discharged on a regular basis.

All batteries involve chemical reactions and every time the reaction goes too far in one direction it becomes less-balanced. If the system is installed to avoid this happening, it is better for everyone involved.

One last thing: you should never buy car batteries and use them in your solar installations. You can get away with this in the short term but will end up paying for it in the long-term.

5. Safety first

A 3kW system is relatively small, but this generates enough power to kill a person. This might seem like an exaggeration, but you need installations that will not be a risk to the customer. When connecting the system to the grid, approval is required as outlined by the Clean Energy Council in Australia.

Most safety issues are caused by installers who are in a rush. Solar panels have been known to catch fire from time to time and in Australian homes, where wood is a major component, this could have catastrophic results. All connections should be properly secured and insulated.

All households and business premises are required to have circuit breakers for protection and getting the electrical energy from the panels to run through this system is a smart move. This will protect the lighting and appliances from overcurrent and overvoltage.

In Australia, the Clean Energy Council gives accreditation to installers. A list of accredited installers can be found here. An accredited installer will safely commission the system or recommission the system in the event that this is needed.

Solar panels and systems should be treated as though they are electrically live and care should be taken in handling system components after storms, excessive wind or anything that could displace the system. Most solar installers can get the panels in place on the roof and a lot of the time the danger is in how the system is wired.


As far as solar installers go, there is no substitute for experience. The mistakes mentioned in this article can be avoided and corrected after the system is installed as well. Getting several quotes can be a tedious process, but is worth it in the long run.

We would rather spend two weeks figuring out the system than spend 25 years regretting buying the wrong solar panel, even though it seemed like a good idea at the time.

An effort must be made to understand the economics of solar systems. Never assume that once installation has taken place feed-in tariffs will be available at the advertised rate. Connecting the system to the grid may take some time and will cost more, so an installer has to consider if this is worth it.

It is not the end of the world if the solar system does not meet every single energy need of the customer every single second of every single day. It may be worthwhile having a smaller system and using other means to meet the refrigerating and heating energy demands of the building.

Batteries last longer if they are not discharged deeply regularly. Deep-cycle batteries are for situations where there is no alternative energy and in systems that are not stand-alone, there is no need to spend the extra money on them. An installer can make sure that the battery rarely discharges beyond 50% of its maximum depth of discharge and then it will last longer.

When it comes to the safety of the people occupying the building, it is extremely important to get the solar system commissioned properly. In Australia, the Clean Energy Commission provides a list of accredited installers, so I would stick with those to be on the safe side.

Many mistakes can be made, but you should definitely avoid these five as a general rule. Solar energy is constantly evolving, and the rules will change from time to time, so as a solar system owner there will be maintenance to do on every system—always be on the lookout for new tricks!

Next Step

If you want to see how much solar or battery storage could save you over the next 5 years, then take our solar saving calculator quiz below!

Or talk to an Instyle Solar expert about the best solutions for home energy storage or PV-panels.

Otherwise, head back to the solar blog to find even more great educational content.

Photo credit: Depositphotos

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