Can I add more solar panels to my system?

Fast read

If you are considering adding more panels to your currently existing solar system, you should consult a professional installation company, as it can be challenging to add more solar panels. Before adding extra panels, it's crucial to consider the capacity of the existing inverter and the evolving Australian solar installation regulations. 

It is also essential to update the complete system to comply with current codes, which may be expensive or economically unviable. If additional room on the roof or a solar battery system is also being explored, adding more solar panels may be a good option if the system is relatively new. 

Installing a second solar system to create a single usable energy source might be more economical. However, you'll need guidance from an experienced local provider or installer before making any selections.

My energy consumption has increased; Can I add more solar panels?

There are a few reasons why one would want to add more solar panels to their existing solar system. These being;

  • Your current solar system is not covering enough of your energy needs;
  • You had an oversized inverter initially installed and want to fill out its capacity; 
  • You want to take advantage of free space on your roof;
  • You want to purchase a battery storage system but need to make more renewable energy for it to be worth it 

If any of these situations sound like you, you can continue reading. Although adding solar panels to your existing solar system is possible, it can sometimes be complex. Before proceeding, you must consider several things and communicate with a professional installer (hopefully your initial one). 

installers carrying panels on roof

Australian solar standards

The first factor to consider is that Australian standards for solar have changed over the years. While you can add more solar panels to your current solar system, these new panels may make it, so your system needs to be updated to the latest standard.

This would mean your entire system would need to be updated, which is often not economical. These issues are predominantly for older solar installations – especially those over seven years, which do not align with current codes.

So when you want to add more solar panels, the installer will be concerned with the whole system being up to scratch and bringing more upgrading costs than you expected for what you thought would be a few extra rails and panels. 

Inverter solution

The next factor to consider is the inverter. Although inverters can oversize by about one-third of their original rating, your inverter can only handle a small number of new solar panels being introduced. It might also comply with the latest inverter standards, meaning you cannot modify the solar system while it’s okay to continue using it. Therefore you would need to replace the inverter. 

This then creates another expense that you should have initially accounted for

When is adding more solar panels a good idea?

installers adding solar panels to solar system
If you have the space, and your system allows differing panel wattage, additional panels are a good idea

So why should you add extra solar panels if it seems so costly? There are a few scenarios where adding additional solar panels is a great idea. Firstly, if you have extra space on your roof and are planning to add extra solar panels, go for it. This is especially true if you initially chose Enphase as your inverter solution, as they allow panels of differing wattage to still work in one system.

As a general rule, putting a second system on will always reduce issues, compared to adding solar panels to an existing solar system, except when the first system was installed very recently, and the inverter sizing was considered a future expansion.

Another scenario where adding extra solar panels to a second system is a good idea is when you are also planning on purchasing a solar battery.

Although solar batteries have a decent upfront cost, they offer a range of benefits – such as blackout protection. Often, when looking to add a second solar system, there will also be battery and panel combos.

In saying this, you will have to pay for the solar battery and a few other items. Usually, there will be the need for a hybrid inverter if you have chosen a DC battery solution. 

As you can see, it’s better to have planned for extra solar panels or installed the biggest solar system initially than to try adding them. Easy in theory – not so easy in practice. 

In summary

Although adding solar panels is an option that is available to all solar homeowners, it is usually only a viable and beneficial option in specific scenarios. The recommended way is to create the biggest system possible in the first place or install a second solar system, given you have the roof space. It allows them to work together and create a decent renewable energy source.  

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