20kW Solar System

A 20kW solar system is a large and future-proof solar system capable of meeting the electricity needs of larger residential properties or small to medium-sized commercial businesses. A 20kW solar system is ideal for properties with significant energy demands and plenty of roof space. It will be beneficial to the owner as it helps reduce reliance on the grid network but also offers long term financial advantages through energy savings. Financial Incentives such as STCs on a 20kW solar system is substantial as it contributes to offsetting carbon emissions on a larger scale than your average size solar system in Australia. An Outback Solar expert can advise you if a 20kW Solar System is the right system for you.

How many panels does a 20kW Solar System consist of?

A 20kW solar system typically consists of around 46 to 52 solar panels, depending on the wattage of each panel. In Australia currently an average size solar panel is between 390 Watts to 440 watts. For example, if I am using a 390W solar panel, then I will require 52 solar panels to achieve a system size of 20,280W or 20.280kW. However, variations may occur based on the solar panels efficiency, dimensions, available roof space, orientation, whether any shading issues are present, and local grid distributor regulations. In 2024, less roof space is required to install a 20kW solar system as opposed to 2011 where the average panel size was 175W-200W – approx. half of the average size panel used today. An Outback Solar Installer can come to your home or business and carry out an on-site measure and inspection to determine how many panels you will be able to fit on your roof.  

How much does a 20kW Solar System produce?

On average, a 20kW solar system can produce approximately 80-88 kWh kilowatt hours (kWh) of electricity per day in Australia, depending on factors such as sunlight exposure, weather conditions, and location of solar panels installed. Over the course of an entire year, this translates to roughly 29,200-32,100 kWh annually.

This level of energy production can power a variety of household or business appliances and devices, making it a versatile option for both large residential homes and moderate size businesses. A 20kW solar system can comfortably power most Australian Homes and Small Businesses. 

There is likely to be excess power generated by a 20kW solar system if your home or business doesn’t consume it. This power is typically exported back to the grid. In Australia, this is known feed-in tariffs and is done through your energy retailers approved net meter installed in your electricity box. Outback solar always advises that you use the solar energy in your home or business rather than exporting back to the grid, as this will offset your electricity charges that you normally pay in excess of 30 cents kWh for.

Would I require 3-Phase Supply for a 20kW Solar System?

Yes, in Australia, 3 phase supply for a 20kW Solar System or larger is required by your grid network provider . If you are considering getting a 20kW solar system then I would assume that you have higher than average power demands. Your property should have three phase power supply or you will need to upgrade to ensure your 20kW solar system provides efficient distribution of electricity across all 3 phases and accommodate higher loads effectively. It’s important to consult with an Outback Solar installer or electrician to determine the best system configuration based on your specific electricity requirements and property type.

What’s the price of a 20kW solar system?

The price of a 20kW solar system depends on the choice of solar panels, inverters, balance of system used, and your property infrastructure, complexity of install and whether you opt for battery storage. On average, in Australia, the cost of a 20kW solar system whether for residential or commercial can be anywhere from $15,000 to $19,000. It will cost more if you were upgrade the supply of your power to 3-phase. 

Australia offers various government incentives and rebates to encourage Australians to switch to solar energy, such as the Small-scale Renewable Energy Scheme (SRES) or commonly known as Small Scale Technology Certificates (STCs). These incentives can significantly reduce the upfront cost of your 20kW solar system. You might also be eligible for a state based battery rebate.  

How many batteries do i need for a 20kw solar system?

Most small businesses that operate during the day don’t require battery storage with their 20kW solar system. However if your home or business does happen to consume electricity during the evening or night, then getting a 20kW solar system with battery storage could be a great idea. This system allows you to store your excess solar energy generated throughout the day and store it to be used in the evening or night.

If you do happen to need battery storage, and lets say you choose to use the Tesla Powerwall battery with your 20kW solar system, here’s an example of how many batteries you might need:

Each Tesla Powerwall has a usable capacity of approximately 13.5 kWh.

Let’s say you want to have some backup power during grid outages and to maximize self-consumption of solar energy. You estimate that you need about 25 kWh of energy storage capacity.

Since each Tesla Powerwall has a capacity of 13.5 kWh, you would need, 25/13.5 = 1.85 batteries which is rounded up to 2 batteries. 

So you will need 2 Tesla Powerwall Batteries with your 20kW Solar System.  

Talk to an Outback Solar expert to help assess your energy consumption requirements and design a 20kW Solar System with or without battery storage.

Can you estimate the savings with a 20kW solar system?

To estimate how much a 20kW solar system will save you depends on many factors such as the install location of the system, your consumption of the solar generated, electricity charges, and your Feed in Tariff that you get when you export back to the grid. On average, a 20kW solar system in Australia can generate approximately 29,200-32,100 kilowatt hours (kWh) of energy output per year, which is quite substantial.

The return on investment or ROI for a 20kW solar system without battery storage is anywhere between 3 and 5 years for small businesses with a moderate energy consumption. For example lets say you buy a 20kW solar system from Outback Solar for $18,000 and you spend 35 cents per kWh on your electricity bill and get a feed-in-tariff of 8 cents. This will be calculated as:

Yearly Energy Savings:

Your solar system generates an average of 29,000 kWh of electricity per year.
40% of the generated electricity is consumed onsite: 29,000 kWh year × 0.4 = 11,600 kWh year.
The remaining 60% is exported to the grid: 29,000 kWh year × 0.6 = 17,400 kWh year.
For onsite consumption, the yearly energy savings would be: 11,600 kWh/year × $0.35 kWh = $4,060 year.
For exported electricity, the revenue generated would be: 17,400 kWh year × $0.08 kWh = $1.392 year.
Total yearly energy savings: $4,060 year + $1,392 year = $5,452 year.

Payback Period:

Using the formula for payback period:

Payback Period = Purchase Price / Yearly Energy Savings
Payback Period = $18,000 / $5,452 which is approximately 3.3 years

Your payback period can take longer If you were to add batteries with your 20kW solar system. Furthermore, Australian government STC incentives, or state based rebates and feed-in tariffs can make your savings even better. Over the lifespan of the system, typically 25 years plus, the cumulative savings from reduced electricity bills can be great.

Our Solar Calculator recommends the ideal solar system for your needs and estimates annual solar production and savings.

A useful resource for Australians interested in exploring energy savings options is the ‘Energy Made Easy’ website, an Australian government initiative designed to help consumers compare electricity offers from different electricity retailers. The website offers tools and information to help consumers understand their energy usage, compare energy plans, and find potential savings. Click Here or Visit www.energymadeeasy.gov.au

Or feel free to speak with an Outback Solar expert who can assess your electricity needs and provide you with a 20kW Solar System Estimate or Quote.

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Contact Outback Solar to get a quote for a 20kW Solar System.