What is a home battery, and what are its benefits?

Unlike solar, which is an energy source that can only be used as it’s being generated, batteries allow you to store energy so that it can be used later at a time that suits you. In other words, they're a 'flexible technology', and they can make things like solar more valuable. 

Depending on what kind of solar you install, a home battery system includes a battery, a control device, and sometimes an additional inverter.  

How does a home battery work? 

As electricity flows from your solar panels into your home, any power not used immediately will be soaked up by the battery. 

Like the rechargeable lithium-ion battery in your phone or laptop, a reversible chemical reaction takes place as the system charges up and then runs down. As the battery discharges energy, lithium ions jump from the negative electrode through an electrolyte to the positive electrode, and then back again during the charging phase.

Once your home battery is fully charged, any extra solar power that you don’t use will be sent to the grid in exchange for a small payment called a "feed-in tariff".

When researching solar and batteries, you might hear about ‘AC’ and ‘DC’ electricity. Solar panels produce ‘direct current’ (DC) power, which is converted by a solar inverter into the ‘alternating current’ (AC) electricity your household appliances and devices need. Batteries like Tesla’s Powerwall 2 are installed after the solar inverter, storing AC electricity that is ready to power your home.

What are the benefits of a home battery? 

Home battery systems offer a range of benefits. They allow you to: 

• Use more of the solar that you generate: Batteries allow you to store the energy your solar system generates so you can use it at a later time.
  
  
• Provide your home with backup power during a blackout: A charged battery can operate independently from the grid. Depending on the battery you install, you may also still be able to generate energy from your solar system to use within your home.
  
  
• Save money by being more involved in the electricity market: A battery can charge from your solar system or the grid. Because the electricity grid is run through a market with a fluid price, you can charge batteries from the grid when the price is lower (depending on your energy plan).
  
  
• Be more independent in how you use energy: As the reasons above show, batteries increase the options you have when it comes to buying, generating and using electricity. 

When should you install a battery?

Batteries can be installed after you install solar panels or when you install solar panels. There is no right or wrong answer – just different things to consider depending on which position you’re in.

Should you buy a battery?

Similar to solar, suitability is generally a question of motivation and expected financial benefit. Batteries are often more expensive than a solar system – but they’re also more versatile in creating value.

Our battery specialists can walk you through the different options available to make sure an outcome can align with the goal you're trying to achieve.