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How does solar battery storage work?

Solar panels are a great renewable energy source, but they only generate energy when the sun is shining. That's when a solar battery can help save energy and cut costs.
6 min read
Published on 27 Jun, 2025

Solar panels are a great way to power the home with renewable energy.

They enable you to use the sun to create your energy supply rather than simply drawing energy from the grid. Using less energy from the grid makes it a cost-effective way to power your home, too – and helps save on your electricity bills.

However, installing solar panels isn’t the only part of creating an efficient energy setup. Installing a home solar battery system can help you rely less on the grid for energy – and help cut costs even further.

Add a battery to your solar power system

Solar panels are a great start, but they can only generate energy when the sun is shining. That’s where a solar battery can help.

Solar battery storage systems store unused energy from your solar panels to use at night, or on a cloudy day. You’re paying for even less energy from the grid, so you can make the most of your solar energy.

Plus, a solar battery system from AGL can speak to other home solar batteries in your neighbourhood to create a  Virtual Power Plant  and support the grid when needed – like on a hot day when lots of people turn on the air-con at the same time.

How do solar panels and batteries work together?

There are a number of components that make up a home solar system. First, you have your solar panels, which feed energy into an inverter. The energy then travels through a switchboard where it’s directed to the appliances in your home.

When the sun isn’t shining, the grid steps in to keep your power running. If you’re generating more solar energy than you need, that energy will go back into the grid and you’ll receive a solar feed-in tariff (FiT) as a credit on your bill.

But if you’ve installed solar power battery storage, the switchboard directs any excess solar energy you are generating to the battery – charging it up for later use. When the sun goes down or you’re using more energy than your panels produce, your battery’s stored energy will power your appliances. And if your solar battery is empty, the grid will lend a helping hand.

Here’s an example of how an AC-coupled battery system works, involving a battery being added to an existing solar system.

Illustration explaining how battery storage works during the daytime
  1. The solar panels take in sunlight.
  2. The solar energy travels as direct current (DC) through the solar inverter so it can be converted into alternating current (AC) energy that everyday appliances can use.
  3. The switchboard then directs the solar energy to where it’s needed. First, it will power the appliances in your home, then direct any excess to the battery inverter.
  4. The battery inverter converts the energy into a form of storable energy.
  5. The battery stores the energy to use for when the sun goes down.

In this scenario, there’s a change in the battery, so energy from the grid isn’t required to power the home.

And then, when the sun goes down…

Illustration explaining how battery storage works during the night

The solar panels stop generating energy and the household switches to stored battery energy.

  1. The battery starts sending energy through the battery inverter to power the home.
  2. The battery inverter converts the energy into a form that appliances can use.
  3. The switchboard directs the energy to your appliances.
  4. When the battery’s charge runs out, the grid will kick in and provide energy to keep your appliances running.

 

Frequently asked questions

Is it worth having battery storage?

That depends on your circumstances, including your energy usage patterns, location and financial goals. If you already have a home solar system and you live in an area with frequent power outages, a solar battery storage system could be worth the investment. 

If you’re a high energy household, or you tend to use more energy at night, you could also benefit more from battery storage due to the increased savings potential. Keep in mind the payback period can take a number of years. 

And if sustainability is a high priority, solar batteries also help you reduce your carbon footprint even more by drawing less from the grid. 

Another point to consider is the upfront cost of your battery – it will take some time for your extra bill savings to “pay back” your investment.  However, thanks to the Federal Governments Cheaper Home Batteries Program, there’s never been a better time to buy a battery.  The program now offers households a discount of around 30% off the upfront cost of a battery system (subject to some eligibility requirements).  This discount will gradually decline each year, so consider getting in early.  

You can get a personalised estimate of the upfront cost, payback period and bill savings for a battery with our Electrify Now tool.

Is a 10kWh battery enough to run a house?

A 10kWh solar battery can hold up to 10 kilowatt hours of power, but its usable capacity is slightly less - around 5-10% lower than actual capacity for lithium-ion based batteries. So if you think about a microwave, which typically uses 1 kW, a 10kWh battery can power it for up to 9 hours. 

Whether a 10kWh battery is enough to run your house depends on the energy you consume and how you intend to use the solar battery. It might be enough if you’re planning to use it to power essential appliances like lights and fridges. Or if you simply want battery storage to reduce peak electricity charges or provide backup power during outages. But if you plan to use it to power continuous off-grid living, a higher storage battery may be better.  

How long will a 10kWh battery last?

The run time of a 10kWh solar battery is influenced by energy usage. And the amount of energy you consume depends on the type appliances you use – and how long you use them for.

What is the lifespan of a solar battery?

Maintenance, monitoring, system quality, as well as environmental conditions, all play a role in the lifespan of your solar battery. Typically, a lithium-ion battery will last between 5-15 years. 

Ready to switch to a brighter way of powering your home?

Learn more about getting a solar battery with AGL.

Get a quote today

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