20kW Commercial Solar Installation: Price, Output and Advantages in Sydney 2025

A 20kW solar system has become the standard size of the solar system for small and medium businesses in Sydney to cut costs on daytime electricity bills. The system costs $13,000 to $25,000 with a government rebate of $7,400. Solar power is cheaper than grid electricity for most businesses in Australia.

How Much Does a 20kw Solar System Cost?

The price of a fully installed 20kW system has fallen dramatically in recent years. The wholesale price of photovoltaic panels continues to be driven down by market conditions, in particular by the growth of solar in developing markets such as India and China.

A 20kW solar system is now less 1/4 of the price it was in 2008. This significant drop in initial outlay allows many businesses to see a return on their investment in well under 5 years, making it an attractive option even if you are leasing your premises.

As a rough guide, the price of a fully installed 20kW commercial solar system starts at around $13,000 – $25,000 and can save you up to around $8,000 a year on your power bills depending on the price you pay for your electricity and how much solar power you are able to use at the time it is generated.

Most businesses will then choose to upgrade their system to high-efficiency panels and to include the latest inverter and monitoring technology. This can increase both the price and the performance of the system. An absolute top-of-the-range system will be in the ballpark of $17,500-$25,000 depending on the site.

Finding the right system for your needs will typically involve a discovery call with one of our representatives, who can run through the pros and cons of the different options.

There are a number of factors that need to be considered when installing a commercial solar system, hence installation costs can vary considerably.1KOMMA5° offers a full installation service, which means we will typically take care of council approval and an engineering certificate. Not all solar installers offer this level of service, however, it is a critical part of the process that ensures a safe installation, and it can also absolve board members of liability in the event of any issue with the roof over the life of the system.

Installation costs can also vary, for example, a shed or barn roof will have very few if any additional installation costs, whereas an apartment building or a ground-mounted array may have additional costs such as long cable runs, crane hire, and site preparation such as clearing trees and laying foundations.

Please contact the 1KOMMA5° Commercial Team for more information. We can provide a full quotation with independent analyses and reports that are accepted and trusted by banks. We can also provide figures for commercial leasing arrangements with $0 money down, and immediate savings from your power bill. A commercial solar power system will often be cash flow positive from day one.

What Does a 20kW Solar System Look Like?

Panels: You'll need 46 x 440W panels.

Inverter: The choice of the inverter will depend on a number of different factors. Often we will install 2 x 10kW inverters to maximise reliability and flexibility with panel design. We only provide the leading models from the largest manufacturers including Enphase, SolarEdge, and Sungrow.

Mounting Kit: 1KOMMA5° can design a mounting solution for most roof types. The two main exclusions are asbestos and slate roofs. For a flat concrete roof please contact us as this will typically require additional work such as waterproofing the booker rods that need to be drilled into the concrete by a roofing professional.

How Much Does a 20kW Solar System Produce?

As a general rule, a 20kW solar power system will output around 80 kWh a day averaged out across the year as illustrated in the image on the right. As illustrated, the system will output more power during the summer half of the year and less in winter. There are a number of factors that influence this figure and these include:

– The location of the system and the expected daily and annual solar irradiation and cloud cover

– The orientation of the roof and the tilt angle of the solar panel array

– Whether there is any shade cast on the panels. For a roof with patchy shade, we recommend SolarEdge or Enphase for panel-level optimisation

– Operating temperature of the panels – it is important to use good quality panels that perform well on hot summer days.

– Whether the solar panel capacity is professionally matched to the inverter’s capacity. This is an important design consideration and our commercial team can discuss this with you in more detail.

– The quality of the individual components. For example, a panel from 1KOMMA5° may outperform a cheaper Chinese-made panel by 10% or more. This can result in further savings on your power bill, especially when extrapolated out over a decade or two.

A 20kW system installed in Sydney with no shade-orientated north can generate up to and over 100 kWh on a sunny day in summer. In winter, when the days are shorter and the sun is lower in the sky, a 20kW system may only produce 60 kWh a day.

When you make an enquiry, our team of commercial solar installers will ask you for a number of power bills to analyse when your business uses its power (both across the day and across the year) to size up a solar power system accurately.

20kW Solar System ROI

A commercial solar power system in Sydney directly reduces your power bills by feeding solar power directly into the main phase of your power supply. Because of this, the potential savings of a solar system depend on how much you pay for electricity when you use it and how much power you use at any one time.

As a rough guide, a 20kW solar system can save you up to approximately $8,000 (this figure will change depending on the price you pay for electricity). For more information, please get in touch with our team of commercial solar installers.

With a possible return on investment now well under 5 years, a 20kW solar power solution is an attractive investment option for your business to reduce short to medium-term operating costs and improve the environmental profile of your business.

Our solar experts will help you find the right system for your home.

Get all the right information before installing a solar power system for your home.