50kW solar systems: Compare prices and installers

50kW is one of the most popular solar system sizes for commercial solar applications in Australia. Any business owner can attest that grid electricity prices have risen dramatically in the past few years, and many are now turning towards solar power as a way to reduce their bill. This article takes a look at pricing, energy yields the factors that influence returns for 50kW solar systems in Australia.

How much does a 50kW solar system cost?

Solar power system prices have fallen dramatically in Australia in the last few years, and more and more businesses are adopting solar PV as a practical way to reduce their operational overheads. Solar Choice has been tracking the cost of commercial solar systems in Australia since 2014, publishing average figures each month in our Commercial Solar Price Index.

Based on this data we can see the average cost of a 50kW system as of August 2024 is $50,480 including the STC rebate and GST. Noting that prices will vary depending on which solar equipment and installers are selected and whether there are any additional costs required (such as crane hire, switchboard upgrades, and long cable runs).

Historically we can see that the cost of a 50kW solar system has more than halved over the last decade.

Average 30kW solar system prices between May 2014 and August 2024. (From Solar Choice’s Commercial PV Price Index.)

How much power does a 50kW system produce?

A number of factors could influence the actual output of a 50kW solar system (or any size of the solar system). These include the system’s geographical location, the orientation and tilt angle of the solar panels, the presence of shading, the operating temperature of the panels and inverter, and the performance of the components used in the system.

The maximum hypothetical yield of a solar PV system is determined first by the amount of incident sunlight that it will see in the course of a day, month, year, etc. Different regions of Australia receive different amounts of sunshine depending on their latitude and climate.

As a rule of thumb, however, a 50kW solar system in Australia can be expected to produce around 4 kilowatt-hours (kWh) per kW of installed capacity per day, averaged throughout the year. This would work out to a total of about 200kWh of solar energy per day for your business. Keep in mind that this figure will fluctuate depending on the system’s location (Brisbane tends to see much more sunshine than Hobart, for example) and the time of year (system output is usually higher in the summertime thanks to the longer days).

Keep in mind, however, that there will be seasonal fluctuations as well. For example, a 50kW solar system in Sydney, NSW would produce about (3kWh x 50kW =) 150kWh of power on a day in the middle of winter, whereas in the summer output from the same 50kW solar PV system would be around (5kWh x 50kW =) 250kWh. A similar system in Brisbane might produce as much as 175kWh in winter and 275kWh on a summer day.

Based on sunlight irradiance history from the Bureau of Meteorology we have calculated the output of a 50kW solar system in all the major cities of Australia in the below table:

Assumptions and limitations of these estimates:

• Figures calculated using PVsyst software
• Assumes solar panels are installed facing north at 5 degrees
• Assumes a conservative system efficiency of 78%

50kW solar system for Grafton Library in Grafton, NSW. (Project tender managed by Solar Choice Commercial.)

50kW solar power installation as part of the Solar in Clubs scheme, Crescent Head, NSW. (Project tender managed by Solar Choice Commercial.)

Solar choice has helped a multitude of Clubs and Pubs across the nation look into their solar potential.

How many solar panels and roof space do you need for a 50kW solar system?

With the efficiency of solar panels increasing rapidly, the output of a single solar panel is exceeding 500W for leading models. For a typical 50kW solar system quote you would be looking at 95 to 115 individual solar panels.

Solar panels in commercial solar projects are usually larger in dimensions than most residential solar panels, often measuring around 1 metre by 2 metres. After leaving an exclusion zone around the edge of the roof and space between the panels for maintenance, you will require around 400 square metres of usable roof space to install a 50kW solar system.

Financial returns for 50kW solar systems – is it worth it?

According to our own data (from nearly 300 business cases compiled in 2021), payback periods for 50kW solar systems in Australia are around 3 years on average, with internal rates of return (IRR) easily hitting 20-30% in every state & territory in the country. After factoring in the benefits of the instant asset write program the government introduced in response to COVID-19 the payback period is currently even better.

That being said, the investment case for installing a 100kW solar system depends on the circumstances. The primary factors that influence solar system ROI are:

1. The up-front and ongoing costs associated with the system
2. The cost of mains electricity
3. Methods of payment/financing for the system
4. The feed-in tariff, if any, for surplus power fed into the grid or sold to a third party.

These are discussed below:

1) Total cost of the system

The 50kW solar system costs we have outlined above (for example $47,940 inc. GST in Sydney as of mid-2022) are average prices for installs without significant extras for complications. Through our tender management service, we have installers’ costs for required extras such as switchboard upgrades, crane hire, ground-mounted systems, tilt frames or micro-inverter systems. There are many companies that would love to throw their hat in the ring for a 50kW system, however, to get the best price and value for your system it is imperative to source a number of quotes from qualified and reputable installers.

2) Electricity prices

Each business is generally in a different position in regard to its purchase power with retailers and ability to access good rates. Factors influencing the electricity costs include the number of sites the business owns and can bargain with to obtain a contract, the geographical location, the local network provider, peak demand charges and time of energy use. Generally speaking the higher your electricity rates means the higher the ROI for a solar project.

3) System financing

Solar can be funded upfront with a payback period of 2-5 years; however many businesses have progressed on a cash flow positive basis under a financing agreement. That means that the repayments on the loan are less than the savings that the solar system delivers which become effective immediately on commissioning the solar system. The business can make moderate savings through the life of the loan and have a step decrease in operational costs are the end of a 5 – 10 year finance agreement. Rates for solar financing are often low between 4 – 6 % depending on project size and credit rating.

To read a balanced review of the pros and cons of all the commercial solar financing options – see our full guide.

4) Solar feed-in tariffs

Generally speaking, commercial-scale solar systems are designed and installed to offset power bills as most commercial power usage is during daylight hours. That said a feed-in-tariff could add the icing to the cake and deliver some benefit to solar power fed back to the grid – e.g. on weekends. Solar Choice’s approach is generally to demonstrate through a business case that the solar project will be viable without a feed-in-tariff as there is in most states there is no mandatory minimum, and it is not guaranteed that a 50kW system will be permitted by the local network to export solar energy.

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Jeff Sykes

CEO at Solar Choice

Jeff has consulted on over 20MW of commercial solar projects, ranging from SMEs to ASX top 100 companies. Jeff has also provided independent advice to 100s of residential solar, battery and EV charging customers across every state in Australia. He holds an MBA from the Australian Graduate School of Management and is an expert in business strategy and financial analysis.

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