Battery-Ready Solar Systems – What You Need To Know

Last Updated: 24th Feb 2024

Many homeowners I speak to are really keen to get batteries with their solar power system. Since the Tesla Powerwall was announced in 2015, batteries have gone from a niche product to something that even the big energy companies like Origin and Energy Australia are selling. 

Unfortunately, the reality is that batteries are still expensive in 2024. For example, expect a 6.6kW solar system + decent-sized good quality battery system to start north of $17,000. Ouch!

Now, there’s nothing wrong with spending that kind of money if the returns/benefits outweigh the cost of buying or financing such a system. That is usually the case with solar-only systems – and explains why over 3.3 million Australian households have installed solar panels.

However, when it comes to batteries, the economics are different and bill reduction is only one aspect some find attractive. They also offer blackout protection (assuming you have the right battery installed), and protection from increases in energy prices / changing tariff structures.

Clued up homeowners who have crunched the numbers (or have had the numbers crunched for them by an honest installer) and deciding not to buy a battery system just yet, are still buying solar systems to which they can add batteries to in the future.

What is a battery-ready solar system?

A truly battery-ready solar system has special kind of inverter (called a hybrid inverter) that allows an installer to easily add batteries in the future. This is known as a “DC-coupled” system. However, the various hybrid inverters available today are only compatible with certain batteries.

But technically speaking (and the good news is) just about every solar power system ever installed can also be considered battery-ready through the use of what’s called AC coupling with a regular solar inverter.  This involves installing an additional “battery inverter” that converts the AC output of the solar inverter back into DC to charge the battery.

I go into greater detail on the pros and cons of both AC and DC coupling in my guide to understanding home batteries. I strongly recommend reading that guide, which will help you determine what may be the better option in your situation.

What’s the point of buying solar now?

You might be thinking that it makes sense to just put off buying solar power until batteries get cheaper, and install both the solar and the batteries in one go.

If you’re considering getting rooftop solar installed, there is no better time than the present. It makes no sense to wait until home batteries drop in price before buying solar panels, because in the interim you’ll lose the savings you will make by having rooftop solar.

This was true before batteries burst onto the scene and it is especially true now.

So, don’t continue to pay big power bills whilst waiting for batteries to get cheaper. I recommend going solar now, but be sure to talk to the installers who quote you about being battery ready.

In that case, I’d rather not leave thousands of dollars in savings up to chance. What do I need to know about purchasing a battery-ready solar system?

A few things:

1) I recommend getting, at a minimum, a 6.6kW solar capacity so you have enough generation capacity to charge your batteries, even in winter (when the sun is weaker). 

2) Consider asking your installer to change their standard warranty document to allow a third party to add batteries to your system without voiding their warranty – if your installer does a great job in the first place, I don’t see why you’d want someone else to install the batteries for you, but this gives you options if you need them.

3) Before going ahead with a future battery purchase, you’ll need to clearly understand how much electricity your household uses at night, to ensure you get enough battery storage.

The best way to do this is when you buy your solar system, get the installer to also install advanced solar monitoring in your switchboard, which will log not only solar electricity generation, but also household electricity use. This will cost an extra few hundred dollars, but it’s money very well spent.

4) Consider whether or not you need backup capability from your batteries. Having this capability increases the overall cost of a system, and not all home energy storage solutions offer this feature.

If you live in a major metropolitan area, blackouts are rare and only last a few hours at most. If your home truly needed backup capability, chances are you’d already have a diesel generator attached to your home.

5) If you have your heart set on a certain brand of battery and are choosing a DC coupled approach – ensure the hybrid inverter will work with that brand.

To get up to 3 competitive quotes for a battery-ready solar system from local solar specialists, simply click the link below:

About Finn Peacock

I’m a Chartered Electrical Engineer, solar and energy efficiency nut, electric car and e-bike owner, dad, and founder of SolarQuotes.com.au. My last “real job” was working for the CSIRO in their renewable energy division. Since 2009 more than 750,000 Australians have used my site to get quotes for high quality PV systems from pre-vetted solar installers.