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Should I Upgrade, Add to or Replace My Old Solar System?

Checked and updated by our licensed electricians: November 2026

Short answer: If your old system still works and is safe, you usually keep it and add to it: a battery (often AC-coupled beside the existing inverter, or with a new hybrid inverter) and, if needed, more panels on a separate inverter. Replacing makes sense when the inverter has failed or is near the end of its life, the panels are damaged or unsafe, or the system is so small that starting again is simpler. Our own electricians check the panels, inverter, isolators and switchboard first.

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New all-black AIKO solar panels installed beside an older solar array on a dark metal roof at Main Arm, Northern Rivers NSW, by Sun Connect Solar
New AIKO panels beside an older array at Main Arm: the old system kept working.

Option 1: keep it and add a battery

Many older systems can have a battery added. Either an AC-coupled battery sits beside your existing inverter, or a new hybrid inverter takes over the old panels and runs the battery. Which one suits depends on the inverter’s age, brand and size. See can I add a battery to my old inverter? and add a battery to existing solar. The battery-ready checker gives a quick answer.

Option 2: add more panels

If your system is small for how much power you use now (an EV, air conditioning, a battery to charge), more panels on a second inverter or a new hybrid can sit alongside the old ones. Mixing new and old panels on the same inverter string is usually not a good idea. See adding more solar panels to an existing system.

New all-black AIKO solar panels beside an older solar system on a metal roof in Mullumbimby, Northern Rivers NSW, installed by Sun Connect Solar
Another Mullumbimby roof with new panels added beside the original system.

Option 3: replace it

  • The inverter has failed or is near the end of its life (inverters typically last 10 to 15 years) and you want a battery anyway: a new hybrid inverter is often the moment to redesign.
  • Panels are cracked, burnt, delaminating or have water inside, or the isolators and cabling are unsafe.
  • The system is very small and the roof could hold a much bigger, modern one.

See how long solar panels and inverters last.

What we check first

  • Panel condition, mounting and roof penetrations.
  • The inverter: brand, age, faults and whether it can work with a battery.
  • DC isolators and cabling, which on older systems are a common fault point.
  • The switchboard and RCBO safety switches. See switchboard upgrades.
  • Your export limit and any old tariff arrangements on your account.

Not working at all right now?

Start with my solar isn’t producing: what to check or book a repair or inspection.

Why Northern Rivers locals choose Sun Connect Solar

  • Our own in-house team designs and installs every system. Licensed electricians, no subcontractors, from our workshop at Wilsons Creek near Mullumbimby.
  • A face-to-face site visit before every install: compliant battery position, switchboard and RCBO check, so there are no surprises on the day.
  • SAA-accredited, a NETCC Approved Seller and a Sigenergy-approved installer, NSW electrical contractor licence 343044C.
  • 25-year workmanship warranty on our installation work, rated 5.0 stars on Google by local customers.

Where we install

Our own electricians install solar and batteries across the Northern Rivers, from our workshop at Wilsons Creek near Mullumbimby: Tweed Heads, Kingscliff, Banora Point, Bilambil Heights, Pottsville, Murwillumbah, Mullumbimby, Ocean Shores, Brunswick Heads, Byron Bay, Suffolk Park, Bangalow, Lennox Head, Ballina, Alstonville and Wollongbar, Lismore, Goonellabah, Coraki and Woodburn, Evans Head. See all areas we serve or the Northern Rivers solar and battery installation page.

Questions we get asked

Can I add a battery to my old solar system?

Usually yes, either with an AC-coupled battery beside your existing inverter or with a new hybrid inverter that takes over the panels and runs the battery. It depends on the inverter’s age, brand and size.

Can I add new panels to my old solar system?

Yes, usually on a second inverter or a new hybrid inverter. Mixing new and old panels on the same inverter string is usually not a good idea.

When should I replace my solar system instead of adding to it?

When the inverter has failed or is near the end of its life, the panels or wiring are damaged or unsafe, or the system is so small that a new design makes more sense.

How long does a solar inverter last?

Typically 10 to 15 years. Panels last much longer, often 25 years or more.

Do you work on solar systems installed by other companies?

Yes. We inspect, repair and add batteries or panels to systems installed by other companies across the Northern Rivers.

Are you independently reviewed?

Yes. As well as our Google reviews, homeowners have reviewed us on SolarQuotes, where we’re rated 4.9 from 22 reviews.

Sources

Last checked 5 November 2026. Written in our own words from the sources below and our own install experience.

Author: our director, in-house head electrician and energy expert, in the trade since 1987.

Want to know what this means for your home?

Start with the free tools (no details needed to see a result): solar and battery price calculator, is my solar battery-ready? checker or the 60-second battery quiz.

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The chat is with our head electrician, about your power bills and what you want from a system. No obligation and no sales script; the firm price comes after we have seen your bills and your home.

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