Get Your 18kW System from a Trusted Solar Installer

Save On Your Power Bills

If you have a large home, run a home-based business, or operate a small commercial space, an 18kW solar system can deliver the high-performance energy solution you need. With enough power to cover heavy daily usage and future-proof your property, it's one of the smartest investments you can make.

Quality and Hassle-Free Solar Installation

We make the process simple. From personalised advice to professional installation by accredited solar experts, we handle everything so you can enjoy reliable solar power without the headaches.

Premium Products, Expert Advice

We only work with trusted, top-tier brands for panels and inverters, backed by industry-leading warranties. Plus, our team takes the time to ensure your system is tailored to your home, your energy needs, and your budget.

Get Your Free Quote Today

4.6

Based on 1.000+ Reviews

Choose the Right Solar System Size For Your Home

Small Systems

Best for: Energy-conscious households, singles or couples working during the day

Average daily output: ~18–28 kWh/day

Roof space needed: ~20–35 m²

Estimated annual savings: $1,000 – $1,500+

5kW system

6.6kW system

7kW system

Medium Systems

Best for: Families with moderate to high energy use (e.g. WFH, EV charging)

Average daily output: ~30–44 kWh/day

Roof space needed: ~35–50 m²

Estimated annual savings: $1,600 – $2,200+

Large Systems

Best for: Large households, multiple appliances, EVs, or battery storage integration

Average daily output: 45+ kWh/day

Roof space needed: 55+ m²

Estimated annual savings: $2,800 – $7,000+

Not sure which one is right for you? Speak with our team today

Why Choose an 18kW System for Your Home:

Bigger System, Bigger Savings

An 18kW solar system generates more power than most households use during the day, helping you slash your power bills and even earn credits by exporting excess energy back to the grid.

Perfect for High Energy Users

Whether you have a large family, run a home-based business, use ducted air conditioning, or charge an EV, an 18kW system gives you the capacity to comfortably power it all, now and into the future.

Designed for Energy Independence

Pair your 18kW system with a battery and reduce your grid reliance even further. Store excess energy for use at night and during blackouts, and take a big step toward full energy freedom.

Ask one of our solar experts about an 18kW system

The Solar + Battery Advantage

Why Solar Alone Is No Longer Enough

Gone are the days when people installed just solar panels. More and more Australians are now pairing their solar system with a battery and for good reason:

Double the Rebates, Double the Savings
By installing both solar and a battery, you can access multiple rebates, stacking the federal solar rebate with the battery rebate to slash your upfront costs.
Feed-in Tariffs Are Dropping
The money you get for sending excess solar back to the grid keeps going down. In some areas, you're even charged to export power. A battery lets you store and use that energy instead.
Unstable Grid? No Worries.
With blackouts becoming more common, having a battery means you can keep the lights on when the grid goes down. Stay powered up and in control, no matter what.

Learn more about battery storage

Customer Stories

"Having solar is the most sensible thing you can do to save money."

Robert, 1KOMMA5° Customer

Here's everything you need to know about installing an 18kW solar system:

Is an 18kW solar system the right size for my home?

An 18kW system is ideal for medium to large households with power bills of $1,200 or more per quarter. It’s perfect if you work from home, run multiple appliances, or have a pool or electric vehicle.

How much can I save with an 18kW solar system?

You could save up to $2,500 to $4,000 or more per year, depending on your location, usage habits, and whether you store or export excess power.

How much roof space do I need for an 18kW system?

You’ll need approximately 90 to 105 m² of roof space, depending on your layout. Most systems today use high-efficiency 450 to 460W panels, so you’ll need about 39 to 40 panels to make up an 18kW system.

Can I add batteries to my 18kW solar system later?

Yes! Most 18kW systems are battery-ready, so you can easily add storage down the track as your needs grow.

Are there rebates or incentives for installing an 18kW solar system?

Yes, government rebates and small-scale technology certificates (STCs) can reduce your upfront cost by thousands, depending on where you live. Typically, rebates for an 18kW system are around $5,900.

How much does it cost to install an 18kW solar system?

The price typically starts from $21,600. Depending on the quality and brand of panels and the inverter, the cost could go up. Premium systems with longer warranties may cost more upfront but offer better long-term value. Be sure to compare quotes and ask about hidden fees or exclusions.

What warranties are available with an 18kW solar system?

At 1KOMMA5°, we only offer premium solar panels and inverters from trusted, high-performance brands known for their reliability. Our own 1KOMMA5° solar panels come with an industry-leading 30-year product warranty, and our 1KOMMA5° hybrid inverter is backed by a 12-year product warranty for your peace of mind.

We also carry other reputable panel brands, most of which include a 25-year product warranty on panels and a 10-year product warranty on inverters.

To give you even more confidence in your investment, every 1KOMMA5° system comes with a 30-year workmanship guarantee so you’re covered, not just for the products themselves, but for the quality of the installation too.

A Smart Future Investment

Premium Solar Panels to Maximise Your 18kW Solar System

The quality of your solar panels is key to how much energy and savings you get from your system. At 1KOMMA5°, we only install trusted, high-performance panels that deliver long-lasting results for your 18kW solar system.

1KOMMA5° Solar Panel Other Solar Panels

Reliability Combined With Efficiency

The Heart of Your 18kW Solar System

Your inverter is what brings your 18kW solar system to life. It converts the energy collected by your panels into usable power for your home. A high-quality inverter means greater energy output, fewer disruptions, and reliable system performance, helping you maximise your solar investment.

1KOMMA5° Hybrid Inverter Other Solar Inverters

You may be eligible for government solar rebates. Check if you qualify.

Get in touch now

Testimonials

Join the 1KOMMA5° movement

Take the lead in climate protection - hear from our customers on how they are making a difference.

Your next steps towards a climate-neutral life:

Step 1: Request a quote online.

After you send your request, one of our expert team members will give you a call.

Request a quote

Step 2: We give you personalised advice and recommendations.

Our energy advisors will create a tailored solution based on your needs. We will explain everything and answer your questions on solar rebates, solar installation costs and process, energy management and more.

Step 3: We install your solar power system.

Once you've signed off on your quote and made a deposit, we will arrange an installation date that works with your schedule.

Step 4: We stay as your energy partner.

Whether you have questions about energy, warranty issues or service or you're looking to expand to other energy efficient solutions, you can reach out to us at any time.

Partners & Accreditations

4.6