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Adding storage to your rooftop solar is easier than ever—yet choosing the wrong inverter can sap efficiency, crimp backup power, and lock you out of future upgrades. For new solar-plus-battery installs, a hybrid inverter delivers the cleanest, most efficient DC-coupled setup. If you already have panels, an AC-coupled battery with its own inverter lets you retrofit without replacing your existing solar inverter. Check each inverter’s battery-compatibility list, size it to your array and household loads, and confirm the model appears on the Clean Energy Council (CEC) approved product list at the time of purchase.
What kind of inverter do you need for a solar battery?
Australians are embracing solar batteries to cushion bill shocks, boost self-consumption, and ride through blackouts. At the heart of every installation is the inverter—the device that orchestrates energy between panels, battery, home loads, and the grid. Whether you’re designing a fresh solar-plus-storage system or adding a battery to an existing array, choosing the right solar-battery inverter is critical for performance, safety, and long-term savings.
Why the inverter matters
Solar panels create direct current (DC) while your household and the grid run on alternating current (AC). An inverter must therefore:
- Convert solar DC to AC for immediate use or export.
- Route surplus energy into the battery—either as DC (preferred) or by re-converting AC to DC in retrofit cases.
- Discharge stored DC back to AC once the sun is down.
- Seamlessly juggle those flows so you always draw the cheapest, cleanest kilowatt-hour available.
Every conversion loses a little energy, so the architecture you choose—DC-coupled via a hybrid inverter or AC-coupled via a dedicated battery inverter—affects overall round-trip efficiency and pay-back.
Hybrid inverters: the integrated choice for new solar-plus-battery systems
A hybrid inverter folds the functions of a solar inverter and a battery charger into one tidy unit, creating a DC-coupled solar-battery system.
How it works
Solar DC goes straight to the hybrid inverter, which either powers the house as AC or charges the DC battery without extra conversion steps. During a blackout, it can supply backup power to selected circuits—many models switch in under ten milliseconds.
Why installers recommend them for new builds
- Higher efficiency: only one DC-AC conversion on discharge.
- Simplified wiring and metering: one box, one monitoring portal.
- Future-proofing: most hybrids are “battery-ready”, so you can add storage later with minimal rewiring.
- Lower hardware cost than two separate inverters of equal quality.
Illustrative brands
- Sungrow SH-RS single-phase (3–10 kW) and SH-RT three-phase hybrids (5–25 kW)— peak efficiencies up to 98.7 % on larger three-phase units and rapid EPS switching for backup.
- Sigenergy SigenStor—a modular “5-in-1” stack bundling hybrid inverter, battery modules (5 kWh or 8 kWh, stackable to 48 kWh per unit), EV DC charger, and AI energy management; the quick-connector design can be physically mounted in under 15 minutes and is engineered for AS/NZS 4777.2 compliance.
Ideal for: anyone installing panels and storage together, or replacing an ageing solar inverter while seeking a high-efficiency box.
AC-coupled battery systems: the flexible retrofit option
If your existing array uses a standard solar inverter that’s still healthy, swapping it out can waste money and will not affect your previously issued STCs—they’re created once, within 12 months of the original install. Instead, add an AC-coupled battery retrofit.
How it works
Your current solar inverter converts the panel DC to AC as usual. Household loads use this AC; any excess is re-converted to DC by the battery’s own inverter for charging. When needed, that inverter sends AC back into your switchboard.
Pros
- Keep your current inverter and monitoring platform.
- Brand flexibility, leading AC batteries (e.g., Tesla Powerwall 2, Enphase IQ Battery 5P) advertise broad compatibility.
- Fast installation—no rewiring of PV strings.
Cons
- An extra conversion step trims round-trip efficiency by roughly four to seven percentage points compared with DC-coupling.
- Two inverters mean two monitoring portals and warranty documents.
Ideal for: households with a three to ten-year-old system still under inverter warranty who want storage now, or landlords seeking minimal downtime.
Planning for future battery upgrades
If storage is still a few years off, you have two clear paths:
Install a battery-ready hybrid inverter now
- Up-front hardware cost is slightly higher, but wiring is done once.
- Efficiency is excellent when you eventually add a DC-coupled battery.
- You are largely tied to batteries compatible with that inverter brand.
Stick with a standard solar inverter and add an AC battery later
- Lowest first-stage cost for a PV-only system.
- Retrofit AC batteries work with almost any inverter brand, giving future flexibility.
- Slightly lower overall efficiency because of the extra conversion steps.
- Lowest first-stage cost for a PV-only system.
Choose the path that best balances cash flow, technology freedom, and how quickly you expect battery prices to fall.
Leading brands and what they offer
Hybrid inverters
- Sungrow: Wide residential and small-commercial range, high conversion efficiencies, single- and three-phase options up to 25 kW AC, with sub-ten-millisecond backup switching.
- Sigenergy: SigenStor’s stackable blocks integrate an inverter, batteries, and EV charger under one AI-optimised control platform.
AC-coupled batteries
- Tesla Powerwall 2 and Powerwall 3: Each provides 13.5 kWh of usable capacity and a built-in inverter; Powerwall 3 can also act as a solar inverter in new builds.
- Enphase IQ Battery 5P: Modular 5 kWh usable blocks that tie into Enphase microinverters for granular monitoring and easy expansion.
These products typically appear on the CEC’s approved product register, but models, firmware, and approval status can change; always check the list immediately before purchase.
Key decision questions
- New build or retrofit? New build = hybrid inverter; retrofit = AC-coupled battery.
- Single-phase or three-phase supply? Match the inverter to your switchboard and local DNSP export limits.
- Battery compatibility? Cross-check both manufacturers’ approved lists.
- Backup power needs? Confirm the inverter’s emergency-power rating and which circuits it can support.
- Monitoring preference? Test-drive the apps; a clear dashboard makes savings obvious.
- Warranty and support? Look for five- to ten-year inverter warranties from suppliers with local service agents and spare parts stock.
Next steps for a smooth installation
- Engage a CEC-accredited designer/installer to size the array, battery, and inverter correctly and comply with AS/NZS 4777.2 and AS/NZS 5139.
- Obtain DNSP pre-approval—often required for systems exporting more than about 5 kW per phase, though exact thresholds vary by network.
- Request written confirmation of battery-inverter compatibility for warranty peace of mind.
- Conduct an energy-use audit so high loads, such as hot-water boosts and EV charging, align with solar-rich hours.
- Offset any unavoidable tree trimming by re-planting native species to protect local biodiversity.
Conclusion: Choose once, choose well
For most new installations, a hybrid inverter delivers the best blend of efficiency, simplicity, and smart-home readiness. When adding storage to existing panels, an AC-coupled battery avoids unnecessary hardware swaps. In both cases, insist on CEC-approved equipment, verify compatibility, and size the system for tomorrow’s electrified lifestyle—EV, heat pump, and all. With the right inverter powering your battery, you’ll slash bills, shrink your carbon footprint, and keep the lights on when the grid falters.
Need personalised guidance? Your Energy Answers can connect you—free of charge—with vetted local experts who will tailor a system to your roof, budget, and energy goals.
