As the cost of electricity rises and the demand for renewable energy grows, more Australian households and small businesses are turning to solar power. One popular choice is a 9kW solar system, ideal for medium to large homes or small businesses with moderate to high energy consumption. In this blog post, we’ll explore the details of a 9kW solar system, including its components, benefits, costs, and production capacity.

What is a 9kw Solar System?

A 9kW solar system refers to a photovoltaic (PV) system capable of producing 9 kilowatts (kW) of electricity under ideal conditions, such as peak sunlight hours. It consists of multiple solar panels that convert sunlight into electricity, which can be used to power household appliances, lighting, and more.

This system size is suitable for households or small businesses with higher-than-average energy consumption, such as homes with electric heating, pool pumps, or air conditioning. A 9kW system is capable of meeting the energy needs of a typical family home or a small office, especially in regions with abundant sunshine.

How Many Panels for a 9kW Solar System?

For a 9kW solar system, you need approximately 20 solar panels if each panel produces 450W. To calculate the exact number of panels, use the formula: 9,000W (9kW) divided by the wattage of each panel. For instance, 9,000W ÷ 450W = 20 panels. If the calculation doesn’t result in a whole number, simply round up or down to get the final count.

Now, most residential solar panels in Australia are between 370w, 415w and 450w. So using the above formula for a 370w you will need around 24 solar panels and for a 415w you will need around 22 solar panels.

I recommend selecting solar panels that produce higher watts and are smaller in size to maximize your roof space. Higher wattage panels will generate more power and occupy less space, making them ideal for residential installations.

How much roof space for 10kW solar?

The space required for a 9kW solar system depends on the size of each solar panel. A typical solar panel measures around 1.8m x 1.1m, so for a 9kW system, you will need around 45 square meters of roof space.

If your roof has an awkward shape or limited space, you can still install a 9kW system. Advanced solar technologies allow for flexible system designs, meaning panels can be arranged to maximize sunlight exposure during peak hours, even on irregularly shaped roofs. This way, you can get the most out of your solar system while using less space.

Using 370W panels (24 panels): 24 x (1.8m x 1.1m) ≈ 47.5 square meters

Using 415W panels (22 panels): 22 x (1.8m x 1.1m) ≈ 43.5 square meters

Using 450W panels (20 panels): 20 x (1.8m x 1.1m) ≈ 39.6 square meters

How much does a 9kw Solar System cost?

You can expect to pay about $8,000 – $12,000 for a good quality 9kW solar system in 2024 after deduction in STC (Small-scale Technology Certificate) also known as solar rebate. The final cost depends on your location, the quality of components, and the installer you choose.

Small-scale Technology Certificates (STCs), often referred to as the solar rebate, can reduce the upfront cost by several thousand dollars.

High-efficiency panels and premium inverters tend to be more expensive but offer better performance and longevity.

Labor and installation charges vary depending on the complexity of the system and your location.

How Much Energy Does a 9kW Solar System Produce Per Day?

On average, a 9kW solar system can produce between 30 to 36 kilowatt-hours (kWh) of electricity per day. On a yearly basis, a 9kW system can generate 11,000 to 13,000 kWh, providing electricity for households or small businesses with moderate to high consumption. The system’s output will depend on several factors:

Areas with more sunlight, like Brisbane or Perth, will generate more electricity than cooler, cloudier regions.

Solar production is higher in summer months and on clear, sunny days.

North-facing panels in Australia with an optimal tilt angle capture the most sunlight.

Shading from trees, buildings, or other obstructions can reduce energy production.

Payback Period for a 9kW Solar System

The payback period for a 9kW solar system is typically 5 to 6 years, depending on your location, energy consumption, and the amount of solar energy you export to the grid (via feed-in tariffs). Homes that consume a large amount of electricity (e.g., over 30kWh per day) will see a faster return on investment.

Factors such as self-consumption (using the energy you generate directly) and feed-in tariffs (payments for exporting excess solar energy to the grid) significantly impact how quickly your system will pay for itself. After the payback period, all energy produced by the system is essentially free.

Can You Install a 9kW Solar System on a Single-Phase Connection?

Yes, you can install a 9kW solar system on a single-phase connection in Australia, but there are some considerations:

Network providers may impose limits on how much power you can export to the grid (e.g., 5kW per phase).

You will need approval from your local distribution network service provider.

Choosing an inverter that complies with network regulations is essential.

Installing devices that limit the amount of power exported to the grid may be necessary.

Benefits of Installing a 9kW Solar System

Investing in a 9kW solar system offers numerous advantages:

  1. A 9kW system can substantially reduce your electricity bills, especially if you have high daily energy consumption. By generating your own power, you rely less on the grid and benefit from lower energy costs.

  2. Solar energy is a clean, renewable source of power. By using a 9kW solar system, you help reduce greenhouse gas emissions and contribute to a more sustainable future.

  3. Australian homeowners and businesses can take advantage of the solar rebate (STCs) to lower the upfront cost of their solar installation.

  4. With solar power, you’re less dependent on the grid, especially when paired with a battery storage system. This can help during power outages or periods of high electricity prices.

  5. Solar panels are seen as an attractive feature for buyers. A property equipped with a 9kW solar system is more energy-efficient and can command a higher price in the market.

Components of a 9kW Solar System

Solar Panels: Approximately 20 to 24 panels, depending on wattage.

Inverter:

  • String Inverter: A single inverter connected to all panels.

  • Microinverters: Individual inverters attached to each panel, improving efficiency in shaded conditions.

Mounting System: Hardware to securely attach panels to your roof.

Optional Battery Storage: Systems like Tesla Powerwall store excess energy for later use.

Monitoring System: Software or apps to track energy production and system performance.

Choosing the Right Installer for a 9kW Solar System

Accreditation: Ensure the installer is accredited by the Clean Energy Council (CEC).

Experience: Look for installers with a proven track record and positive customer reviews.

Quality Components: Verify that the installer uses reputable brands with strong warranties.

After-Sales Service: Choose a company that offers ongoing support and maintenance services.

Transparent Quotes: Obtain detailed quotes outlining all costs, components, and expected performance.