5 kilowatt (5kW) solar systems have become one of the most popular sizes in Australia, thanks 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 that a household can expect from a 5kW solar PV 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 about 15-20 panels and will require about 25-35 m2 of roof space, depending on the wattage of the panels and how they’re tilted. You can explore your own roof’s solar potential here.
How much do 5kW Solar Systems cost?
Australia is home to some of the lowest solar PV system prices in the world, thanks to a broad combination of global and local factors. According to Solar Choice’s own data, the average 5kW solar system price in Australia as of October 2019 is about $1.09 per watt – or about $5,180, with a low of well under $1/W ($2,050) and a high of about $1.40/W ($7,000).
The table below, from February 2019, provides a snapshot of price trends for 5kW solar systems in capital cities around the country.
5kW solar PV system prices from across the country from August 2012 to October 2019.
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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
-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, although 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. This is only the annual average per day, and 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 February 2019.
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
(Assuming 25kWh electricity consumption/day @ 25c/kWh)
(assumes 11c/kWh feed-in rate from March 2019)
(assumes 8c/kWh feed-in rate)
|@ 30% self-consumption||@ 50% self-consumption||@ 30% self-consumption||@ 50% self-consumption|
|~3.7 year payback||~2.9 year payback||~4.8 year payback||~3.8 year payback|
|~27% IRR||~35% IRR||~20% IRR||~27% IRR|
|~$1,124 annual savings||~1,426 annual savings||~$1,030 annual savings||~$1,330 annual savings|
(assumes 11.3c/kWh feed-in rate from March 2019)
(assumes 8c/kWh feed-in rate)
|@ 30% self-consumption||@ 50% self-consumption||@ 30% self-consumption||50% self-consumption|
|~5 year payback||~3.9 year payback||~3.3 year payback||~2.6 year payback|
|~20% IRR||~26% IRR||~30% IRR||~40% IRR|
|~$1,071 annual savings||~$1,373 annual savings||~$1,107 annual savings||~$1,463 annual savings|
Try plugging some figures into our solar system ROI calculator yourself.
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