What Size Solar System Do I Need in Australia?

Factors To Consider Before Sizing Your Solar System

Investing in a solar PV system is a popular way to harness renewable energy in Australia, but choosing the right size to suit your energy needs is essential. Here are some things to consider before sizing your solar system:

Budget: Budget is a factor that must be carefully considered, especially for those who have never installed a solar system. Currently, solar power is cheaper than ever in Australia. Generally speaking, the larger the solar panels you need, the more affordable the price per kilowatt capacity. So, consider your solar system's equipment and installation costs in advance.

Peak Sunshine Hours: Peak sunshine hours refer to when your solar panels receive the most direct sunlight. The peak sunshine hours in your area will affect the size of your solar array and whether you want to include battery storage in your solar plan.

In Australia, peak sunshine hours generally occur between 10 am and 3 pm, but this can vary depending on several factors, including latitude, season, traffic volume and partial shading.

The following chart shows the peak sunshine hours in different Australian states. 

The following chart shows the peak sunshine hours in Australia during different seasons.

Roof Space: The size, orientation, and layout of your roof space will affect the size of the solar system you can install. Solar panels need to fit in your roof space physically and avoid obstructions such as vents, antennas, or chimneys.

When you use the most electricity during the day is also a factor to consider when considering the size and location of your solar PV system. In Western Australia, north-facing solar panels are generally the most effective because these solar panels will capture the most direct sunlight during the hottest part of the day.

However, a well-designed solar system should be installed on your roof in a direction that matches your household's electricity usage patterns. For example:

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What Size Solar System Do I Need? 

One of homeowners' biggest questions when switching to solar is how big a solar system they need. The truth is, there is no one-size-fits-all solution for solar. So you need to know how much electricity you use and when you use it daily to know what size solar system will meet your electricity usage.

Sizing a solar system requires calculating the specific setup to generate, store, and deliver the electricity needed to power your home. You must determine the size of your solar system based on your expected electricity usage and available space.

Step 1: Calculate your home's electricity usage.

The first step in sizing your solar system is calculating how much electricity your home uses. The easiest way to do this is to look at your electric bill for an accurate estimate, as your electricity usage may vary depending on the season and time of year.

• Add 12 months of electricity consumption and divide by 12 to get your average monthly electricity usage.
• Divide your monthly electricity usage by 30 to determine your daily kilowatt-hour usage.

Step 2: Find out how much sunlight your area receives.

Once you know your home's electricity usage, you need to see the amount of sunlight your location receives. Solar panels generate electricity when they absorb, develop, and store the sun's energy during peak sunlight hours.

Knowing your location's peak sunlight hours can help you estimate how much energy your solar panels will generate and how large a solar system you will need.

Step 3: Reckon the size of the solar system that you need.

If you want to calculate your solar system's detailed size, plug the information above into the following formula to estimate its size.

kWh of typical daily usage / average peak sun hours * 0.8 = solar array size.

Step 4: Choose a Grid or Off-Grid Solar System

Once you've decided on the size of your solar system, you'll also want to compare grid-connected vs. off-grid solar systems. Choosing a grid-connected or off-grid setup is the first thing many solar system buyers discuss with friends and family. However, most agree that grid-connected solar systems offer more flexibility.

Grid-Connected Solar System

A grid-connected solar system is the most common type in Australia, with solar panels and an inverter connected to the primary grid. The solar system provides power during the day, with the home typically using solar power first and then grid power.

A grid connection provides power at night (assuming no batteries are connected) and at other times when the solar system can't generate enough power, such as when the sun isn't shining enough.

Off-Grid Solar System

An off-grid solar system is detached from the primary grid, meaning all of the home's power comes from the solar system and possibly other types of generation, such as wind. Off-grid systems require more solar capacity than a typical grid-connected system. They may also need an inverter to handle higher loads and peak demand.

Off-grid solar systems are usually only suitable for remote areas without a grid connection. Suppliers with particular expertise in such systems should design and install them so that the cost is prohibitive.

Step 5: Common Solar System Sizes

A 6.6kW solar system usually powers the average Australian home. However, the exact size of the solar system depends on your electricity usage, usage time, and budget. The following table shows the most common solar system sizes (assuming you are using a 400 W solar panel with a production rate of 1.5)

What Are the Components of a Solar System?

What does a solar system consist of? The main components that come with every solar system or solar panel kit include:

• Solar Panels
• Inverter
• Mounting
• Solar charge controller
• Batteries

1. Solar Panels

A single panel consists of multiple solar cells that are silicon wafers connected and held in place by a back sheet, a frame, and a piece of glass.

A solar array refers to all the solar panels that comprise a system. It may consist of one or more panels connected to a string inverter or any number of panels individually paired with a microinverter.

Types of Solar Panels

The main types of solar panels on the market are multicrystalline, monocrystalline PERC, and half-cut. Each type has advantages and disadvantages.

1. Inverter

Inverters are also responsible for directing the flow of current between system components. Most inverters offer monitoring solutions to track the performance of the system.

There are various types of inverters available on the market today:

• String Inverters
• String Inverters with PV Optimizers
• Micro Inverters
• Storable Inverters

1. Mounting

The mounting is the base structure that holds the solar panel. The mounting system has mounting rails and flashing to secure the rails to the roof or ground mount. Most home solar systems fall into two categories:

• Roof-mounted mounting
• Ground-mounted mounting

1. Batteries

In solar energy systems, battery banks are needed to store available power, which is helpful in the event of grid failures, extreme weather, or other disruptions. Types of batteries in solar energy systems:

• Flooded lead acid batteries
• Sealed lead acid batteries
• Lithium batteries

How Many Solar Panels Do I Need?

How many solar panels do you need? How many solar panels does an average home need? How many solar panels does a three-bedroom home need? How many solar panels does a 2,000-square-foot home need? These are all questions often asked by homeowners interested in installing a solar energy system. So, how do you determine how many solar panels your home needs?

To decide the number of solar panels your home needs, look at three things:

• Your current energy usage (kWh)
• Peak sunshine hours in your area
• The size of the solar panel

You can plug the relevant data into the following formula to find the number of panels you need:

Number of Panels = Daily Energy Usage / (Panel Wattage * Peak Sun Hours)

Factors That Decide the Number of Solar Panels

Many factors will influence the number of solar panels that are right for you, from your energy habits and roof features to environmental factors and your personal solar goals and budget.

Electricity Usage: The electricity you use dramatically impacts how many solar panels you need. If you use a lot of electricity, you'll need a lot of solar panels.

Solar Panel Wattage: Higher-wattage solar panels produce more electricity than lower-wattage ones. So, if you choose higher-wattage solar panels, you can install fewer solar panels.

The following table lists the number of solar panels you need to meet the average household's electricity usage (based on 6.5kWh)

Roof Features: Some roofs have obstructions, such as chimneys, vents, and skylights, which can limit the number of solar panels that can be installed. If you have these obstructions on your roof, it may reduce the number of solar panels you can install.

Jackery Solar Generators Explained

Your budget, geography, and energy usage determine the size of a solar system. When estimating your needs, consider portable options like Jackery Solar Generators. These small systems can be added to your primary solar array to provide extra electricity for emergencies or outdoor activities.

With the flexibility offered by Jackery's products, you may maximise the use of renewable resources and expand your energy solutions. Jackery is the ideal addition to any solar system, regardless of whether you need power for a single device or your entire house.

Jackery Solar Generators deliver a stable power source that reduces dependence on traditional electricity, helping to lower monthly bills. When paired with Jackery Solar Panels, the Portable Power Station maximises energy capture and storage, giving households dependable backup power.  

Jackery Solar Generator 2000 Plus

The Jackery Solar Generator 2000 Plus sets a new benchmark in portable power solutions, offering unparalleled performance, safety, and durability. This solar generator is designed for longevity and reliability and is built with a LiFePO4 battery that boasts a 10-year lifespan and 4,000 charging cycles.

Flexible Power for All Household Needs: With an impressive 2 kWh capacity that can be expanded to 12 kWh, the Jackery Solar Generator 2000 Plus supports various household appliances and tools with a powerful 3000W output. This flexibility is perfect for managing high-energy devices, providing backup during peak rate times, and keeping your energy bills low. This feature makes it a competitive option compared to traditional energy providers with rising costs.

Eco-Friendly, Quiet Operation: One of the Explorer 2000 Plus's standout features is its silent, emission-free operation. Running on a long-lasting LiFePO4 battery, it can operate for over a decade with daily use, providing a quiet, pollution-free solution suitable for home and outdoor use. Solar charging capability harnesses renewable energy that's better for the environment and offers long-term savings compared to fluctuating utility rates.

Jackery Solar Generator 1000 Plus

The Jackery Solar Generator 1000 Plus is designed sustainably, offering whisper-quiet operation and zero emissions. Its advanced IBC solar technology ensures a quick and efficient recharge in 4.5 hours with four SolarSaga 100W panels, even in low-light conditions.    

Expandable Backup Power and Efficiency: With a 1264Wh capacity that supports up to three additional battery packs, the 1000 Plus can expand to 5kWh. This setup offers 1-3 days of reliable backup power, ideal for keeping essential devices running during peak periods or outages. Its 2000W output can power most small-to-medium-sized household appliances, offering an economical and flexible alternative to traditional power.

Ultra-Fast Solar Charging and Multiple Power Options: Equipped with Jackery's advanced solar charging technology, the Explore 1000 Plus reaches full charge in just 4.5 hours when used with four SolarSaga 100W panels. These efficient solar charging and AC and car charging options ensure you're always ready with renewable energy when needed. This flexibility helps reduce reliance on grid electricity, especially in NSW, where rates vary widely throughout the day.

How to Choose a Solar System?

Are you considering buying a solar system for your home or business? Solar systems are a great way to reduce your electricity bills. However, it would help if you took the time to determine which is right for you. Here are some tips to help you choose the best solar system for your needs:

Determine Your Power Needs

Firstly, you should determine how much energy you need to generate. Considering your current electricity usage and how much you want to offset with solar power will help you decide what system is best for you.

Check Certifications

Before buying solar system components, ensure they have the necessary certifications. Look for products certified by BIS, ALMM, IEC, ISO, or other industry-recognised organisations, indicating that the solar system components have been tested and approved for residential applications.

Compare Prices

Once you've narrowed down your choices, it's time to compare solar system prices. Shop around to find the best deal. But remember that quality is always the top consideration.

Great Customer Service

The quality of solar system components varies from manufacturer to manufacturer. So look for a reputable brand that offers solar systems with a good warranty (usually 25 years). Its warranty should also cover defects and performance issues.

FAQs

The following are the frequently asked questions about the size of the solar system you need in Australia.

1. How big does the average Australian home need a solar system?

The average Australian home typically needs a 6.6kW solar system of 16 to 18 solar panels.

However, the exact size of your solar system depends on your electricity usage, time of use, and budget.

2. Why is choosing a more extensive solar system recommended?

Choosing a more significant system size than you need is recommended as long as you can afford the upfront costs and have enough roof space. Here are the reasons why it is recommended to choose a more extensive solar system:

• Increasing feed-in tariffs.
• Lower costs for large solar systems.
• Faster payback.
• Future planning for storage or more uses.

3. What affects the output efficiency of solar panels?

Various factors affect the output efficiency of solar panels, mainly shadows and lousy weather.

Dust: A solar panel's ability to absorb sunlight can be affected in particularly dusty areas or where there are many birds or bugs. So make sure to inspect the solar panels visually once a month and, if necessary, hose them down with a water hose in the evening when the weather is not too hot.

Ice & Snow: Although rare in most parts of Australia, ice and snow can prevent solar panels from absorbing sunlight.

Overheating: Overheating can make solar panels inefficient. For example, a panel casing temperature of 50 degrees Celsius can reduce energy capture efficiency by 10% to 15%.

Final Thoughts

Switching to solar power isn't just for the green good; it's a long-term investment that can add value to your home and get you off the grid. So, if you've decided on or are considering a solar system, you need to know what size solar system you need to make your home as solar-powered (as possible).

While many solar system sizing calculators are available online, there are many different factors and considerations to consider. We've compiled this simple guide to help you determine your home's correct solar system size.