What are the Different Types of Solar Batteries?

Types of batteries in the renewable energy market vary based on their use cases. In this blog we dive into the types of batteries AusPac Solar acquires for its customers and its projects across the board in Residential, Commercial and Off-Grid systems.  

The type of battery you get really comes down to one thing: What’s its purpose going to be?

And the purpose of a battery therefore is, again, subjective to what your needs are.  

Homes with 4 people living there shouldn’t need more than a 5 – 10kWh battery to charge and run your appliances in peak time.  

Off-Grid solar systems can have implemented anything up to 100kWh of battery storage, for a business or farm that needs more than 100kW per day to run its operation.  

It’s about measuring your usage with what tech is available to us.

There are two types of batteries AusPac Solar implements in its projects:

  • Lead-acid  
  • Lithium-ion

Here’s some info on the two.  

Lithium-ion batteries can come as AC or DC coupled.  

AC and DC are the two types of electronic current that can service the home. Solar panels convert sunlight into AC power which can then be stored as either AC or DC in your home. AC coupled batteries can be connected to existing systems meanwhile DC coupled  

The most popular home for solar batteries is lithium-ion.  

Lithium-ion batteries can come as AC or DC coupled.  

AC-coupled batteries can be connected to existing solar panel systems, while DC-coupled batteries are most suited for being installed at the same time as solar panels.  

So, let’s talk through the use-cases of each battery-type.

Lead Acid Batteries

The tried and tested true technology of the renewable energy world, these deep-cycle batteries have been used to store energy for a long time. They're your stock-standard battery. And they’ve stuck around cause they’re so reliable.  

The two types of lead acid batteries: Flooded lead acid and sealed lead acid.  

The reliability of lead acid batteries is great for off-grid solar systems or for emergency back-up storage in case of power outage.  

Pro’s:

  • Cheap
  • Reliable
  • Easy recycling and disposal  

Con’s:

  • Require regular maintenance  
  • Installation limitations  
  • Short lifespan  

Lithium-ion Batteries

The new kids on the renewable energy storage block. As electronic vehicles begin to rise, EV manufacturers realised lithium ion’s potential as an energy storage solution. They quickly became one of the most widely used solar battery banks.

One of the biggest disadvantages of lithium-ion batteries is that they are more expensive than other energy storage technologies.  

Lithium-ion is best for residential installations because they can hold more power in a limited amount of space and enable you to use more of the energy stored within the battery for powering the home. Australia is the biggest producer globally for producing lithium producing 86,000 tons, double that of the world’s second-largest producer, Chile at 44,000 tons.  

Pro’s:

  • Require little maintenance  
  • High energy density  
  • Longer lifespan  

Con’s:

  • High upfront costs  
  • Increase chance of thermal runaway if installed poorly  

Common reasons to buying a battery:

  • Your bills have increased, and a battery will help you mitigate your energy usage
  • You use a lot of your appliances in the evening and require a battery to do so.  
  • You’d like to turn your current system into a Hybrid system  
  • You’d like to earn some extra cash and send kW back to the grid during peak times (non-Sun Tax Times)

FAQs:

1. I have Solar, but I don’t have a battery

If you’re considering a battery for an existing system, first consider if your inverter is Hybrid ready (can fit a battery). If you have a single grid-connect system, then you will need to get a new inverter so it can fit a battery.  

This will incur a cost to source a new inverter, so if you are yet to get a solar system but don’t need a battery consider getting one in case you will need one in the future. Futureproofing yourself can be a smart way of saving yourself costs in the future.  

2. I have a battery but I’m getting taxed on sending kWh back to the grid, how can I avoid this?

The best way to avoid a Sun Tax is by speaking to your energy provider regarding when the best time to send kWh back to the grid is. They will likely tell you that between 5pm – 9pm (peak time) is the best time. You’re sending kWh back to the grid at a time where the grid is at max capacity, so kWh being sent in is benefiting an under-strain grid.  

If you have a large enough battery to send to the grid and power your home, why not. But of course, if you have a smaller battery, it’s probably best to take care of your needs first, right?  

In this scenario with your energy provider, you can negotiate your nominal feed-in tariff. We recommend that anything between 11-15c per kilowatt-hour should be what you’re aiming for.