It may not be worthwhile to purchase solar panels and batteries in a number of circumstances. Installing a large enough solar system to reduce your electricity bill significantly might not be feasible if you have a tiny roof or no space for a ground-mounted installation.
Before installing solar panels, it may also be required to repair or replace your roof if it is in poor condition, for example, if it is composed of asbestos tiles or is prone to shattering.
It might not be economical to purchase solar panels if your home is frequently shaded or you have a low electricity expenditure. Last but not least, it might not be wise to spend money on a solar system you won't be able to take with you if you intend to relocate soon.
What are the situations where it’s not worth getting solar and batteries?
Some people should not get solar panels for a variety of reasons. Some solar salespersons are not always ethical and may try to persuade you to purchase solar when it’s not in your best interest.
When the following information applies to you, we recommend you not get solar.
Too much shade can make solar production fall significantly
Another reason I wouldn’t get solar is if you have a lot of shade. Yes, there’s a technology that can handle shade on panels. If it is, for example, half shaded, microinverters can allow each panel’s output to work independently from each other, but if some of the PV systems panels are shaded the whole day, then those panels, and the panels connected to their same string in case of string inverter technology, will produce very little electricity.
Suppose your roof has many trees surrounding it and is completely shaded and/or is shaded most of the day. In that case, solar might not be the solution for you. Maybe apply energy efficiency measures to reduce your electricity bill in those cases.
Don’t install solar if you have a very small roof
If you have a small roof, you will have less impact on reducing your electricity bill. Many properties, such as townhouses or terraces in the inner city, lack sufficient roof space to accommodate an extensive solar system. The smallest solar system an installer typically sells nowadays is a 3-4 kW system.
If you use 400W panels, you’ll need ten panels to create a 4 kW solar system. Because each panel will be around 1.8 x 1m, you’ll require a suitable roof of at least 20 to 30 square meters to fit a 4 kW system.
Most of the time, nowadays, a standard solar system starts at 6 kW, meaning a minimum of 15 panels and can go as high as 10 kW and more for typical residential systems.
Alternatively, if you have a roof with many gables that point in many different directions, it will be difficult to fit many panels. Therefore, when you can only get a very, very small solar system on your roof, it’s not even worth getting solar in the first place.
Also, if you have a big backyard, you may opt for a ground-mounted system where you can fit a lot of panels on the stand-alone frame. Nevertheless, in inner city tight roof terrace houses, the backyards are often small, and one will most likely lack backyard space for a ground mount array.
Do not install if you have asbestos tiles, brittle terracotta tiles or rusted metal roof sheets
One of the most important things I found when I’m on site is if somebody has an asbestos roof. You do not want to put solar on it because you have to drill into the tiles, which is not advisable. It might even be illegal.
So if you have a roof with asbestos roof tiles or just a roof in poor condition, the best way to spend your money is to replace that roof before you move on to solar.
Regarding the roof, old terracotta tiles, can be very brittle. It’s next to impossible to install solar on such a roof because when the installation crew members walk across the roof, they weigh 90 to 100 kilos, especially if they carry a panel on top of it. The result will be many broken tiles and potential water penetration into your roof post-install.
Brittle terracotta and concrete roof tiles will make the installation next to impossible. One has to have tiles in good condition for solar to go on. So in these cases, when the roof conditions are relatively poor, it is worth spending the money on the roof before you move into solar.
If you are wondering whether or not you have asbestos in your roof, you can read our guide for more information here.
Do I need solar if my electricity bill is already small?
Also, if you have a relatively small electricity bill, maybe $150 to $250 per quarter, in those cases, I wouldn’t go for it. I think you’ve got to have a minimum bill of $250 to $300 per three months before solar really is worth it. Check your bill to see how much electricity you consume daily. It may be difficult to justify the financial benefits of solar power if you use less than 10 kWh daily. If you don’t think solar is worth the investment for your particular situation, you can read our guide on how to save electricity without investing in solar panels.
You will not be living in the house for a long time
Suppose you’re thinking of selling your house in two or three years. In that case, it’s probably not worth putting solar on right now because the return on investment will usually be between three, four, or five years, depending precisely on the type of system you’re purchasing. So if you’re only thinking of having the house for a short period, then it’s not worth getting solar. For more information, you can read the City of Sydney’s guide to home solar.