Can I run my air conditioning on a solar battery in Brisbane?

It’s one of the most common questions I hear from Brisbane homeowners, especially during those long, humid summers: can a solar battery really handle the air con?

The short answer is yes. The longer, more helpful answer is that it depends entirely on having the right-sized system. Running an air conditioner, which is one of the most power-hungry appliances in any home, requires a solar and battery setup that is specifically designed for the task.

Success comes down to a few key factors:

• The power draw of your air conditioner: Not all units are created equal.

• The capacity of your solar battery: How much energy it can store.

• The output of your solar panels: How much energy you can generate to run the air con and charge the battery.

• The power rating of your inverter: Its ability to handle the large surge of power when the AC compressor kicks in.

Getting any of these elements wrong can lead to a system that struggles on hot days or, worse, shuts down when you need it most. But with proper planning, you can definitely enjoy solar-powered cooling and significantly reduce your reliance on the grid.

How much power does a typical home air conditioner use?

The first step is to understand what you’re up against. The power consumption of an air conditioner is measured in kilowatts (kW) for its running power and kilowatt-hours (kWh) for its energy use over time.

A typical modern split-system air conditioner in Australia uses between 0.8 kWh and 2.5 kWh of electricity per hour, depending on its size and efficiency. Smaller window units might use between 500 to 1,500 watts (0.5 kW to 1.5 kW) while running.

Here’s a quick reference table for common split systems:

However, the most critical factor for a battery system is the startup or ‘peak’ power. When an air conditioner’s compressor first turns on, it can draw a huge amount of power for a few seconds—often 3 to 7 times its regular running wattage. This initial surge is what can trip an undersized inverter.

Gigi’s Pro Tip: Check the compliance plate on the side of your air conditioner’s outdoor unit. It will list the ‘Rated Input’ or ‘Rated Current’ in watts (W) or amps (A). This gives you the running power, but remember the startup surge will be significantly higher. An SAA-accredited installer can measure this peak load accurately.

What is the average solar battery capacity for homes in Brisbane?

For a Brisbane household looking to cover most of their evening and overnight energy needs, a solar battery with a usable capacity of 10 kWh to 13.5 kWh is the most common and effective size. This range strikes the best balance between cost and performance for the average family.

• 10 kWh batteries: This is often considered the sweet spot. A 10 kWh battery, like a Sungrow SBR (9.6kWh usable), can comfortably power essential loads like lights, a fridge, and a TV through the evening, and can handle a few hours of sensible air conditioner use.

• 13.5 kWh batteries: Larger units like the Tesla Powerwall 3 (13.5kWh usable) are better suited for households with higher energy consumption, such as those with an electric vehicle, a pool pump, or a desire to run the air conditioner for longer periods overnight.

A 10-13.5 kWh battery is generally sufficient to cover the 10-12 kWh of electricity an average household consumes after the sun goes down.

What size solar panel system do I need to run an air conditioner and charge a battery?

To reliably run your air conditioner during the day while also fully charging your battery for nighttime use, a standard 6.6kW solar system is often the minimum starting point. However, for many Brisbane homes, a larger 10kW system is a smarter investment.

• 6.6kW System: This is the most popular system size in Australia. In Brisbane, a 6.6kW system produces an average of 26-28 kWh of electricity per day. This is generally enough to cover a typical family’s daytime usage (including some AC) and still have enough excess energy to charge a 10kWh battery.

• 10kW System: For homes with higher energy usage (over 30 kWh per day) or those wanting to run the air conditioner extensively, a 10kW system is ideal. It provides more buffer on overcast days and ensures your battery gets fully charged, even when the AC is running for several hours. A 10kW system in Brisbane can cost between $8,000 and $12,000 after rebates.

How do I calculate a solar battery’s runtime for my air conditioner?

Calculating the exact runtime is straightforward. You simply divide the battery’s usable capacity (in kWh) by the air conditioner’s power consumption (in kW).

Formula: Battery Capacity (kWh) / Appliance Power (kW) = Runtime (hours) Example: You have a Tesla Powerwall 3 with 13.5 kWh of usable capacity. Your air conditioner consumes 1.5 kW while running.

Calculation: 13.5 kWh / 1.5 kW = 9 hours

This means you could theoretically run that specific air conditioner continuously for 9 hours on a fully charged battery. Remember to also account for other essential appliances running overnight, like your refrigerator, which will reduce the total time.

What inverter requirements do I need for my air conditioner?

This is where many people get stuck, but it’s crucial for success. Your system’s inverter must have a continuous power rating high enough for the AC’s running draw, and a peak power rating strong enough to handle its startup surge.

• Continuous Power: This is the power the inverter can supply steadily. If your AC runs at 1.5 kW, your inverter needs a continuous rating higher than this, plus enough to cover any other appliances running at the same time.

• Peak Power (Surge Power): This is the maximum power an inverter can deliver for a few seconds. If the AC’s startup surge is 7,000 watts (7 kW), the inverter must have a peak rating of at least 7 kW. Most quality inverters have a peak rating that is double their continuous rating.

Modern all-in-one battery systems like the Tesla Powerwall 3 are designed with this in mind. The Powerwall 3 has a high continuous power output of up to 11.04 kW, making it more than capable of starting and running most residential air conditioners.

How much does it cost in Brisbane to install a solar and battery system capable of running air conditioning?

For a system in Brisbane robust enough to handle air conditioning, you should budget for a 6.6kW to 10kW solar array and a 10-13.5kWh battery.

In 2025, the total installed cost for such a system typically ranges from $15,000 to $25,000.

Here’s a general cost breakdown:

• A quality 10kW solar system: Approximately $8,000 – $12,000.

• A 10kWh – 13.5kWh solar battery: Approximately $9,000 – $14,000 (installed).

The great news for homeowners is the Federal Cheaper Home Batteries Program. This national rebate, which began on July 1, 2025, can reduce the upfront cost of a battery. For a typical 10kWh battery, this can result in a saving of approximately $3,440.

Case Study: A Family in The Gap The Kumar family was facing quarterly power bills of over $600, especially in summer. They installed a 10kW system with Trina panels and a 13.5kWh Tesla Powerwall 3 for a total cost of $22,500. After the federal battery rebate of about $4,700, their outlay was closer to $17,800. Their annual savings are now over $2,500, putting them on track for a payback period of just over 6 years, and their last summer electricity bill was almost entirely made up of the daily grid connection fee.

Making the right choice for your home

Running your air conditioning from a solar battery is an achievable goal for Brisbane homeowners and a powerful way to take control of summer electricity bills. It requires a thoughtful approach to system design, ensuring your panels, inverter, and battery are all correctly sized for the job.

By investing in a capable system, you not only gain comfort and energy independence but also make a smart financial decision that pays for itself over time.

If you’re feeling overwhelmed by the options, I can connect you with a trusted local expert who can provide a detailed quote based on your home’s specific needs. Just fill out the form below to get started.