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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.

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.

Install 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, an AGL solar battery system helps you support your local community. It 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.

 

Frequenty 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, you could also benefit more from battery storage due to the increased savings potential. Keep in mind the payback period can take more than 10 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. 

But if your budget is tight, you may consider delaying solar battery storage to when you can afford the $10,000+ upfront installation costs. You can also look out for state-based government rebates for solar batteries to help ease the expenses. 

Is a 10kWh battery enough to run a house?

A 10kWh solar battery can hold 10 kilowatt hours of power. That means it can produce 10 kilowatts (kW) of energy per hour. So if you think about a microwave, which typically uses 1 kW, a 10kWh battery can power it for 10 hours. 

Many solar powered households and small businesses opt for 10kWh solar battery storage systems. Whether it’s 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. 

If you’re powering a minimal number of small household appliances like lights and fans, a 10kWh battery can last up to 13-14 hours. But based on the average energy consumption for Australian households during a power outage, it’s more likely to last around 10 hours with ongoing usage. 

What is the lifespan of a solar battery? 

Battery maintenance, usage patterns and chemistry, as well as environmental conditions, all play a role in the lifespan of your solar battery. Typically, a 10kWh battery will last around 10-15 years for household use. The more common lithium-ion batteries tend to last 10-12 years, whereas LiFePO4 (lithium iron phosphate) batteries can last up to 12-15 years with proper care.

Your charge/discharge patterns, that’s the process of charging the battery then discharging it to provide power, can also impact the lifespan of your solar battery. If you completely discharge (empty) the 10kWh battery, that can shorten its lifespan. Exposure to extreme hot or cold weather can also speed up the degradation of the battery. 

How do I get a solar power system started?

Ready to switch to a brighter way of powering your home? Learn more about whether installing solar is right for you.

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