Installing solar with an existing battery backup system.

Posted January 2024

Can you install solar with an existing battery backup system?

Chances are you already have a battery backup system installed in your home, which should give you some relief from load shedding in the months to come. However, with the ever-worsening energy crisis, you may be thinking that it’s time to switch to solar power so that you’re no longer reliant on the national power grid. 

If you have an existing battery backup system, how easy is it to upgrade it to a solar system in your home using your existing equipment? What are the questions you should be asking when it comes to a solar setup, and what are the steps involved? In this article, we unpack all you need to know.

What equipment do you currently have?

The first step in upgrading your battery backup system to a solar system for home is to assess the size and type of batteries and inverters you currently have powering your house for load shedding. This is important because not all equipment works well or is compliant with a solar PV system, even if it is advertised as being so. Beware that some electricians may not be knowledgeable about which inverters are suitable for solar and which are not.

Once you’ve made sure your equipment is compliant, you can move ahead with the next step of adding on solar PV panels. Alternatively, you may need to replace some of the components of your current system in order to make them suitable for a solar installation. Bear in mind too that municipalities and Eskom require that only specific approved and tested inverters on their list can be installed, so check that the ones you plan to use are on this list.

What generation capacity do you need?

Next, look at how much power you want to generate in your home. A good place to start is to look at how many units of electricity you’re currently using each month. From there, you or your solar installer will be able to make projections and accurately size the number of solar panels you’ll need – including panel degradation – in order for your home solar system to cater to your household’s power needs.

What solar panels will you use?

After your equipment has been checked or upgraded, the next step is to look at the solar arrays (i.e. the number of solar panels) you need to meet the yield you need. Each installer will have their own supplier(s) of solar panels, so it’s worth asking them questions about the panels they use. Specifically, the panels should be monocrystalline, and they should come with both a 25 year performance warranty and a 12 year manufacturer warranty. While all solar PV panel cells degrade over time, these warranties will guarantee that the degradation will be at the specified rates. After 25 years, it’s usually around 85% give or take the panel’s maximum rated capacity.

Who will do the upgrade?

While an ordinary electrician can install a battery backup system, engineering expertise is needed for a solar system installation, as knowledge is needed about setting the inverter up with the grid, battery and panels as well as technical details like MPPT (maximum power point tracking) input limitations, solar arrays optimisations, battery communication protocols and SANS compliance wiring/switch gear etc. An engineer will also be able to assess your roof integrity to ensure that it can hold the weight of the panels to be installed and to check the roof type for the correct roof mounting structure as to ensure waterproof seals.

What is the design process?

There are a number of options you could go with for how your home solar system is designed, depending on your budget and your current versus future power needs. For example, if you’re limited in terms of budget, you could install a minimum number of panels now and then scale up in future. The options available to you will also depend on what the existing electrical setup of your house is and what solar space you have available. 

When it comes to upgrading your existing battery backup system to a solar PV system, make sure you do your research first. Whichever provider you go with, make sure they’re accredited and can provide a turnkey solar system that is specifically suited to your house and your power needs.

At SSESA, we’ll work with the engineer who installed your battery backup system to convert it to solar. We’ll also do the small-scale embedded generator (SSEG) application on your behalf. Most importantly, all our systems are fully upgradable – whether that means replacing the inverter you have so it can support a solar system, or adding more solar panels in future.

Want to upgrade to solar? Talk to us today about your energy goals in the short, medium and long term.