5 kilowatt (5kW) solar systems have become one of the most popular sizes in Australia. This due to the combination of high energy yields and great value for money that they deliver. What are the price ranges, electricity yields and financial returns you can expect from a 5kW solar system? This article takes a look.
How many panels & how much roof space for a 5kW solar system?
A modern-day 5kW solar system will be comprised of between 15-20 panels. It will also require about 25-35 m2 of roof space, depending on the wattage of the panels and how they’re tilted. Solar panel sizes vary depending on brand and whether they are designed for commercial or residential use, but most commonly panels are around 1.7 metre by 1 metre on a 5kW system.
How much do 5kW Solar Systems cost?
Australia is home to some of the lowest solar system prices in the world, thanks to a broad combination of global and local factors. According to the Solar Choice Price Index, the average cost of a 5kW solar system in Australia as of July 2023 is about $1.13 per watt – or about $5,640 – after the STC rebate has been deducted and including GST.
Below, you can see the full breakdown of how that average cost varies by capital city in Australia.
5kW solar system average costs by Australian city
- This pricing includes the Goverment STC rebate and GST, but excludes state based rebates like Solar Victoria
- These are average prices, difficult installs on concrete or tile roofs will be more expensive
- The quality of solar system equipment you select will also influence the price
History of 5kW solar system prices in Australia
The graph below shows how the cost of a 5kW solar system has declined over the past decade. It’s broken down by state capital cities around the country.
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How much power will a 5kW Solar System generate?
Depending a number of factors, the actual power output of a 5kW solar power system will vary. These factors include:
- Geographical location of the system and the expected daily and annual solar irradiation and cloud cover levels there
- Orientation and tilt angle of the solar panel array
- Whether there is any shade cast on the panels
- Actual operating temperature of the panels
- The performance of the individual components (e.g. the panels and the inverter)
As mentioned in the first point above, different areas receive different amounts of sunlight. The amount of sunshine falling on a solar panel array has a direct impact on the system’s output. As a rough figure, a rooftop in Australia can expect to receive around an annual average of 4.5 hours of ‘peak sun’ (peak sun hours, or PSH) per day. This number may range as high as 5.8 PSH per day in places like Darwin or as low as 4.2 PSH per day in Tasmania. It is important to keep in mind that there will be more sun in the summer and less in the winter months.
Example: An optimally tilted, 85% efficient, north-facing 5kW solar system in Sydney, for example, would produce about (3.5 PSH x 5kW x 85% =) ~15kWh of power on a day in the peak of winter, whereas in the summer output from the same 5kW solar system would be around (6.2 PSH x 5kW x 85% =) ~26kWh. (Figures are only to be taken as rough estimates.)
What is the financial return on a 5kW Solar System?
The financial returns from a 5kW solar installation are a bit harder to work out, and mainly contingent on whether or not a solar feed-in tariff is available to the owner/operator of the system. Solar Feed-in Tariff schemes pay solar system owners a set amount for each unit of solar power that they export to the electricity grid.
Examples using Solar Choice’s solar power system ROI calculator
Using Solar Choice’s Solar PV System Return on Investment Calculator, we’ve calculated indicative payback periods, annual internal rates of return (IRR) and annual savings (in year 1) using 5kW solar systems for common usage situations in some major cities based on average system prices as of July 2023.
Payback times depend heavily on the amount of solar energy that you consume directly vs export to the grid (‘solar self-consumption ratio’), so we’ve included both ‘low’ (30%) and ‘high’ (50%) scenarios.
If you do not or cannot use much electricity during daylight hours, you’re more likely to be on the ‘low’ end of the self-consumption spectrum, while if you do use a lot of energy during the day (e.g. because you’re home or because you can run devices like dishwashers while you’re away) then you may be on the ‘high’ end.
|Indicative returns for 5kW solar systems @ average prices|
|Location||Price||Energy Rate||Feed in Tariff||Self Consumption Rate||Annual Saving||Payback Period|
|Sydney||$4,750||27c / kWh||7c / kWh||30%||$1,044||4.5 Years|
|Sydney||$4,750||27c / kWh||7c / kWh||50%||$1,459||3.2 Years|
|Brisbane||$5,580||26c / kWh||5c / kWh||30%||$988||5.5 Years|
|Brisbane||$5,580||26c / kWh||5c / kWh||50%||$1,419||3.9 Years|
|Melbourne||$5,420||21c / kWh||5c / kwh||30%||$773||6.7 Years|
|Melbourne||$5,420||21c / kWh||5c / kwh||50%||$1,104||4.8 Years|
|Perth||$4,860||31c / kWh||5c / kWh||30%||$1,150||4.1 Years|
|Perth||$4,860||31c / kWh||5c / kWh||50%||$1,680||2.9 Years|
- We have assumed that the household consumes an average of 25 kWh per day
- We have used energy rates and feed in tariffs towards the sharper end of what’s available on the market using EnergyMadeEasy
- Pricing is based on the Solar Choice Price Index from July 2023
Try plugging some figures into our solar system ROI calculator yourself.
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