Fast read
Solar batteries work best with rooftop solar systems by storing excess energy your panels generate during the day and making it available when you need it most—like at night or during cloudy weather. This maximises your solar self-consumption, reduces reliance on expensive grid power, and can significantly lower your electricity bills. To get the best results, your battery system should be correctly sized to match your usage, configured with smart controls for time-of-use optimisation, and installed by a Clean Energy Council (CEC) accredited professional to ensure it meets Australian safety standards.
How Solar Batteries and Rooftop Solar Systems Work Together
You’ve invested in rooftop solar, but how do you make the most of that clean energy after the sun goes down? For many Australian homes and businesses, the answer is a solar battery. When integrated intelligently, batteries can transform your solar system from a daytime-only solution into an all-day energy strategy. This article explains how solar batteries work with your rooftop solar, the key benefits, and how to optimise their performance.
Maximise your solar self-consumption
The primary way a battery enhances your rooftop solar system is by increasing solar self-consumption—that is, using more of your own solar energy instead of exporting it or relying on the grid. Here’s how it works:
- During the day: Your solar panels generate electricity. Your home uses this power first.
- Excess generation: When solar production exceeds your home’s demand, the surplus energy usually gets exported to the grid for a small feed-in tariff.
- Battery charging: Instead, with a battery installed, the excess solar charges your battery.
- Evening or cloudy days: When solar output drops, your home draws on stored energy from the battery, rather than buying power from the grid.
This process significantly increases your use of solar energy. While a standard solar-only setup might cover 30–50% of your electricity needs, adding a battery can push that figure to 80% or even higher.
What else do batteries offer beyond self-consumption?
Time-of-use savings (load shifting)
Many Australians are on time-of-use electricity plans, where grid power costs more during peak hours (typically evenings). A smart battery system can be set to discharge during these expensive windows, helping you avoid high tariffs.
Backup power during outages
Some batteries, like the Tesla Powerwall or Sungrow SBR series, can provide backup during blackouts. If grid independence is important to you, make sure your battery is islandable—able to operate when the grid is down. Some systems also allow your panels to keep charging the battery during an outage.
Virtual Power Plants (VPPs)
By joining a Virtual Power Plant, your battery becomes part of a network that supports grid stability. In return, you may receive payments or bill credits. Popular VPPs in Australia include those run by AGL, EnergyAustralia, and Amber Electric. Reducing export limits and curtailment. In some parts of Australia, DNSPs cap how much solar you can export to the grid. A battery helps by storing energy that would otherwise be wasted due to export limits, making your system more productive.
How does the technology integrate?
Inverters: The crucial middleman
- Solar inverters convert your panels’ DC electricity into AC for household use or export.
- Battery inverters (in AC-coupled systems) handle battery charging and discharging separately.
- Hybrid inverters (used in DC-coupled systems) manage solar, battery, home, and grid interactions in one unit.
For new installations, hybrid inverters (like those from Goodwe or Sungrow) are often more streamlined and cost-effective.
Choosing the right battery for your system
Chemistry matters
- Lithium Iron Phosphate (LFP): Safer, longer lifespan, stable in high heat—ideal for Australian conditions.
- Nickel Manganese Cobalt (NMC): More compact but can be more sensitive to temperature and less durable long term. Brands like Alpha ESS and Sonnen typically use LFP, while Tesla Powerwall uses NMC with sophisticated thermal management.
- Size it to your needs
- Usable capacity (kWh): Match this to your evening and overnight consumption, not just your system’s output.
- Power rating (kW): Affects how many appliances the battery can run at once.
- Depth of Discharge (DoD): Most lithium-ion batteries allow 90 %+ DoD—check this for lifespan and blackout reserve planning.
- Cycle life and warranty: Look for batteries rated for at least 6,000–10,000 cycles and backed by a 10-year warranty.
Many newer systems are modular—start small and add capacity later if needed.
Optimising your battery’s performance
Use smart controls
Modern battery systems include apps and software that monitor usage, forecast solar output, and optimise when to charge or discharge. Some even integrate weather data to prepare for cloudy days.
Align usage with solar production
Try to run large appliances (like dishwashers or pool pumps) during solar peak hours so the battery can store what’s left over for evening use.
Monitor regularly
Check your battery’s app or portal to track performance and ensure you’re getting the most from your system.
Safe, compliant installation is non-negotiable
Use accredited professionals
Only hire CEC-accredited installers. They’re trained to meet stringent Australian safety and performance standards.
Meet all Australian Standards
Your battery must comply with AS/NZS 5139 for safety and siting, plus AS/NZS 3000 electrical rules. These standards cover:
- Fire safety and ventilation
- Safe battery locations (e.g., not in habitable rooms)
- Cabling and installation protocols
Battery installation rules in Australia are strict for good reason—choose a reputable installer who knows them inside out.
Is a battery worth it?
Whether a battery is financially worthwhile depends on your usage patterns, tariffs, system size, and upfront cost. But beyond dollars and cents, batteries offer energy independence, resilience, and future-proofing—especially as feed-in tariffs fall and electricity prices rise. Some states offer rebates or interest-free loans (e.g., NSW Solar Battery Rebate), which can significantly improve payback time.
Conclusion: A smarter, cleaner energy future
Solar batteries work best when integrated thoughtfully into a well-designed rooftop solar system. That means sizing the battery correctly, using smart controls, installing with accredited professionals, and choosing reputable brands suited to Australian conditions. Done right, they can dramatically reduce your power bills, improve energy security, and help create a more resilient and sustainable grid.
If you’re ready to explore whether a solar battery is right for your home, Your Energy Answers can connect you with trusted local professionals for an expert assessment and quote—completely free.
