Adding a home battery is not a one size fits all decision.
Some homeowners already have solar installed and simply want to add storage. Others want to add a battery and more solar panels at the same time. Some may want the flexibility to add more solar in the future. Others are starting fresh with a new solar and battery system.
The right design depends on your existing equipment, your roof space, your energy usage, your backup needs, your future plans and your local network requirements.
The infographic explains three common battery solution designs in a simple way.
1. Battery Only Retrofit
This option is usually used when you already have solar panels and an existing solar inverter.
Your existing solar system stays in place. A new battery and battery inverter are added to your home. The battery inverter manages the battery and works alongside your existing solar inverter.
In this design, the existing solar inverter continues converting solar power for the home. The battery inverter uses metering information to understand what the existing solar system is producing and what the home is using.
This is why the diagram shows two meters:
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A solar production meter, which monitors the output from the existing solar inverter
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A house load meter, which monitors the overall energy usage of the home
These meters help the battery inverter decide when to charge, when to discharge and how to support the home.
This option is best for homeowners who already have solar and want to add battery storage while keeping their existing solar inverter.
2. Retrofit Plus Optional Extra Solar
This option is useful when you already have solar, but also want to add battery storage and either add more solar panels now or keep that option open for the future.
The existing solar panels and third party solar inverter can remain in place. A hybrid inverter is added to manage the battery. Depending on the system design, additional solar panels can also be connected to the hybrid inverter now, or added later as part of a future upgrade.
This gives the homeowner more flexibility and growth potential.
The existing solar system continues to operate, while the hybrid inverter manages the battery and any additional solar connected to it.
Like the battery only retrofit option, this design typically uses two meters:
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A solar production meter for the existing solar inverter
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A house load meter for the whole home
The key difference is that this option can support extra solar generation, either immediately or in the future, depending on the inverter, roof layout, battery size, system design and network requirements.
This option is best for homeowners who already have solar but want more storage, more flexibility and the ability to grow the system over time.
3. New Hybrid Solar Plus Battery System
This option is usually used for a new solar and battery installation, or for a full system replacement.
In this design, one hybrid inverter manages the solar panels and the battery together. The solar panels connect to the hybrid inverter. The battery also connects to the hybrid inverter. The hybrid inverter then manages energy flow between the solar panels, battery, home and grid.
This is often the cleanest and most integrated design because one inverter manages the full solar and battery system.
In this setup, the system still needs a house load meter. This meter monitors the whole home energy usage so the hybrid inverter can understand when the home is importing, exporting, charging or discharging.
This option is best for new solar and battery installations, new homes, full replacements, or homeowners wanting a cleaner integrated system design.
What Do the Solid Lines and Dotted Lines Mean?
In the infographic, the solid arrows show energy flow.
That means the direction electricity can move between the solar panels, inverter, battery, home and grid.
The dotted lines show metering and monitoring.
Meters do not move energy. They provide information to the inverter so the system can make the right decisions.
A simple way to think about it is this:
Solid lines are the power roads.
Dotted lines are the information signals.
Both are important. The power lines move energy. The metering signals tell the system what is happening.
Which Option Is Best?
There is no single best design for every home.
As a simple guide:
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If you already have solar and want to add a battery, a battery only retrofit may be suitable.
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If you already have solar and want to add more solar now or allow for future solar expansion, a retrofit with optional extra solar may be suitable.
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If you are installing a new solar and battery system, a new hybrid solar plus battery system may be the cleanest and most integrated option.
Final Takeaway
The best battery solution is the one that matches your home, your existing solar system, your energy usage and your future needs.
A good design should consider:
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Whether you already have solar
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Whether your existing inverter will remain
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Whether you want to add more solar panels now
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Whether you may want to expand the system later
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Your battery size
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Backup requirements
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Local network connection rules
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Available wall space and switchboard layout
Before choosing a solution, speak with your installer about the right system design for your home.
A well designed battery system can help you store more solar, reduce grid usage and make better use of the energy your home already produces.