How to Upgrade Your Solar System in 2026: A Practical Guide

If you installed solar five or more years ago, you made a smart call. At the time, the deal was simple: panels on the roof, lower bills, excess power sold back to the grid at a decent rate. For most households, it worked exactly as promised.

But the energy landscape in Australia looks quite different now. Feed-in tariffs have dropped significantly, electricity prices have climbed, and households are using more power than ever, particularly in the evening when solar panels aren't generating. Meanwhile, battery technology has matured from an expensive experiment into a genuine option for everyday homes.

None of this means your original decision was wrong. It means the rules around it have shifted. And if your system was designed to maximise daytime export to the grid, it's probably not set up to deliver the savings it could under today's conditions.

This guide walks through what's changed, what to check, and how to plan a practical upgrade path, whether that means a new inverter, a battery, more panels, or some combination of all three.

When solar first took off in Australia, systems were designed around one main idea: generate as much power as possible during the day and send the excess to the grid. That approach worked well because feed-in tariffs were higher, daytime exports were rewarded, and battery storage was expensive and uncommon.

Today, several things have shifted at once.

When people think about upgrading solar, they tend to think about batteries. That makes sense. Batteries are the exciting, visible upgrade that promises to store your surplus power for later. But before you get to batteries, there's a less glamorous component that often needs attention first: your inverter.

Your inverter converts the DC power from your panels into the AC power your home actually uses. It also manages how energy flows between your home, the grid, and any battery you add later. If the inverter is limited, the whole system is limited, even if the panels are fine.

Many inverters installed five or more years ago were designed for a simpler job: push power to the grid during the day and handle basic import/export. They often lack battery compatibility, detailed monitoring, and the flexibility to handle modern grid requirements. This is the quiet bottleneck in thousands of Australian solar systems.

Here's the critical point that catches people out: you can't properly add a battery without the right inverter setup. Some older systems aren't battery-ready at all. Others can only support certain battery types or require an inverter upgrade before storage can be added. If you add a battery to an incompatible inverter, you often end up paying for two separate upgrades instead of one.

Replacing the inverter is often the step that unlocks everything else: battery compatibility, better self-consumption, smarter energy management, and the ability to expand your system down the track. It's not the flashy upgrade, but it's frequently the most impactful one.

You can compare modern inverter options, including which ones pair with which batteries, on our inverter comparison page.

If your solar system was installed before 2018, you're in a specific category that's worth understanding. These systems were typically designed during a period when feed-in tariffs were still reasonable, battery storage was rare, and inverters were simpler. The assumptions baked into your system's design no longer match how most households use power.

The good news is that your panels are almost certainly still working. Solar panels degrade slowly, typically losing less than 0.5% of their output per year. A system installed in 2016 is probably still producing 95% or more of its original capacity. Panels are rarely the weak link.

Before spending anything on upgrades, check these things.

One of the biggest reasons people put off upgrading their solar is the assumption that it means ripping everything off the roof and starting again. That's almost never the case.

Solar upgrades are modular. For most systems installed in the last 10 to 15 years, the panels are not the problem. They degrade slowly, they continue producing power for decades, and they don't need replacing unless they're damaged or significantly undersized.

The parts that typically get upgraded are the components around the panels.

This is probably the most common question from homeowners with existing solar: "I want to upgrade, but what do I upgrade first?" The answer depends on what problem you're actually trying to solve.

To make this concrete, here's what a staged upgrade might look like for a fairly typical household: a family in suburban Sydney with a 5kW system installed in 2016. The system is still generating power, but they're exporting most of it during the day for 5 cents per kWh and buying power back at 35 cents per kWh in the evening. Their bills have been creeping up for a couple of years.

Some solar upgrades, including batteries, inverter replacements, and system expansions, may be eligible for state or federal incentives depending on where you live and how your system is configured. Eligibility criteria vary between states and change periodically, so it's worth checking what applies to your home before committing to any upgrades.

You can use our rebate eligibility quiz to get a clearer picture of which incentives may apply to your situation. It takes a couple of minutes and gives you a personalised summary based on your state, system type, and upgrade plans.