Investing in solar battery storage brings you one step closer to fully harnessing the sun’s free energy to reduce your electricity bills. But … how do you know which size of solar battery is right for your property?
Choosing the right battery size is key to ensuring optimal performance and cost-effectiveness, so to help you choose the right size battery straight off the bat, we’ve put together a straightforward process to follow.
Why solar battery size matters
While making sure you’ve got the right size is only one of the key things to look when buying a solar battery, it’s one of the most important if you want to maximise the benefits of your system.
If your battery is too small, you might not be able to store enough energy to meet your household needs when the sun isn’t shining – drawing power from the grid to top up. On the other hand, if your battery is too large, you could end up with excess storage capacity that you don’t use, which means higher upfront costs without any benefits.
Learn more: Can you use solar panels and electricity at the same time?
What is the average solar battery system size in Australia?
In Australia, a common battery setup includes an 8 kW solar panel system paired with a 10 kWh battery. This configuration typically provides a good balance between energy generation and storage, allowing you to reduce reliance on the grid and save on electricity costs.
Think you’ll use more than that? Upgrading to a 15 kWh battery would give you more capacity to cover any significant power usage at night, or extra security during an outage.
- Pro tip: Solar batteries are modular, meaning you can start with a smaller battery and add more storage capacity later if needed.
How to choose the right solar battery size for your household
1. Understand your energy consumption
The first step in choosing the right size solar battery for your needs is to understand how much energy you use every day. You can usually find this information on your electricity bill – it’s often displayed in a bar chart that shows your usage in kilowatt-hours (kWh) per day.
Let’s say your household currently uses 28 kWh per day, but you plan to use your air conditioner more frequently during the summer. To account for this increased usage, you might estimate your daily consumption will rise to 32 kWh per day.
It’s also essential to think about your future energy needs. If you’re thinking about buying an electric vehicle, installing new air-con or adding more energy-consuming appliances, it’s wise to adjust your estimated daily kWh accordingly. Want to know more about investing in EV chargers or heat pumps? Give us a call – we can help.
2. Size your solar panels
Once you have a rough estimate of your daily energy consumption, the next step is to determine the solar panels you’ll need. A simple rule of thumb is to divide your daily kWh usage by four. This gives you the size of the solar panel system in kilowatts (kW) that will likely be sufficient to meet your average needs.
Calculation: Daily usage (kWh) / 4 = ideal solar panel system size (kW)
Example: If your estimated daily energy usage is 32 kWh, dividing by four results in eight. Therefore, an 8 kW solar panel system would be suitable for your home.
Learn more: How long do solar panels last in Australia?
3. Determine the right solar battery size
Now you have estimated household consumption and an ideal solar panel system size – time for the battery.
The goal with solar batteries is to store enough energy to meet your household’s needs when the sun isn’t shining, such as at night or during cloudy days, without over-spending on capacity you don’t require.
To estimate the correct battery size, you’ll need to multiply the size of your solar panel system (in kW) by 1.5. This calculation gives you a middle mark in terms of the kWh of battery storage you might need.
Calculation: Solar panel system size (kW) * 1.5 = average ideal battery size (kWh)
Example: For an 8 kW solar panel system, multiply eight by 1.5 – resulting in 12. Therefore, a 12 kWh battery would be a good starting point for your energy storage needs.
- Pro tip: There’s a lot of flexibility here, so you’ll need to tailor these estimates to make them work for you. For instance, multiplying your energy usage by 1.5 might not be enough for a household with high evening usage, because the battery would work out to be too small. This is where it pays to get a solar and battery installation expert in for assistance with all the maths.
Ready to get your solar battery sorted?
Determining the right solar battery size involves understanding your current and future energy needs, sizing your solar panels accordingly, and then choosing a battery that fits your energy consumption profile. By following this simple guide and working with a trusted local solar installer, you can ensure that your solar power system is both efficient and cost-effective.
Here at Think Renewable, we have offices across Australia and a team of experts ready to get stuck in to help you out. We offer personalised, no-obligations consultations, and we know how to estimate the best battery sizes and brands for any property.
To take the next step, book a consultation today and let’s talk.
