Perth WA Best Solar PV system deals

Find the best solar power deals in Perth, WA

by Solar Choice Staff on March 14, 2016

in Solar and Renewable Energy Policy,State Government solar feed-in tariffs,WA

Perth, WA is a great place to install a solar power system. Like most of Australia, in Perth retail electricity rates are rising, and solar installation prices have fallen significantly over the past few years, thanks in part to the financial subsidies available through the federal government. How much does a solar system cost in Perth, and how do you know if you’re getting a good deal on a system?

Why is Perth a good place for solar power?

1. Perth gets lots of sunshine

When you own a solar system in Perth, more sunshine means more savings, so it’s useful to know what to expect. According to PVWatts, Perth receives an annual average of around 5.8 hours of ‘peak sunshine’ per square meter per day – making it one of Australia’s top solar cities.

These 5.8 hours of sunshine are the ‘fuel’ for a solar system. The larger the system, the more of this fuel it can capture and turn into usable energy. The table below shows typical energy output for solar PV systems of various sizes in Perth (assuming the system is 80% efficient, which is typical).

Solar PV system output in Perth (Popular system sizes)
Solar system size (kilowatts)
Avg daily system output (kilowatt-hours)
1.5kW 7kWh
2kW 9kWh
3kW 14kWh
4kW 19kWh
5kW 23kWh
10kW 46kWh

2. Solar energy helps Perth homes save money on their power bills

Having a solar system on your roof is basically like owning your own power station: The energy from the solar panels can be used to run the appliances in your home, thereby allowing you to bypass your electricity retailer for a portion of your electricity needs. Of course, you don’t use all of your electricity during daylight hours (when your panels produce power), so the solar energy that you produce can only cover a portion of your bills. (Unless you add on battery storage, that is – you can read more about battery storage in Perth here.)

Household demand varies by the size of family and the appliances used and how frequently, but as a ‘base case’, the average 3-person home uses about 20kWh of energy per day, averaged over the course of a year. Depending on your home’s electricity consumption pattern, you may only use as little as 30% of this when the sun is shining. In such cases, the remaining 70% of the solar energy will be sent into the grid, where it will earn you only about 8c/kWh – far less than the retail rate for electricity. Essentially, unused solar is ‘wasted’. For this reason, it’s important to choose a solar system size to meet your daytime electricity needs.

(For educational organisations & not-for-profit customers: Synergy offers generous feed-in tariff rates for not-for-profit, schools, and community organisations. This makes going solar a great investment. Read more: Solar Buybacks for not-for-profits, schools, and community organisations in and around Perth, WA.)

3. Government incentives mean low solar system prices in Perth

Under the federal government’s Renewable Energy Target scheme, households and businesses installing systems up to 100kW are eligible to receive certificates where effectively act as an up-front ‘discount’ off the price of a solar system. depending on their location, the size of the system that they install, and the market price for STCs at the time of installation. In Perth, this discount can cover over 30% of the up-front cost of a system – or about $1,500-$2,000 for a 3kW solar system.

The table below shows the price per watt ($/W, 1kW = 1,000W) for various solar system sizes for Perth from March 2016. A 3kW system contains 3,000 watts (W), while a 10kW solar system contains 10,000W. (Read more about current solar system prices here.)

Perth solar system prices March 20164. Rooftop solar promises favourable returns and short paybacks for Perth households

Indicative returns for solar systems @ average Perth prices

(Assuming 20kWh electricity consumption/day, retail electricity @ 25c/kWh, solar feed-in rate @ 8c/kWh)

1.5kW 2kW
$2,250 $1,965
@ 50% self-consumption @ 70% self-consumption @ 50% self-consumption @ 70% self-consumption
~6.2 year payback ~5.1 year payback ~4.1 year payback ~3.4 year payback
~13% IRR ~18% IRR ~23% IRR ~30% IRR
~$350 annual savings ~$430 annual savings ~$470 annual savings ~$570 annual savings
3kW 5kW
$3,600 $5,850
@ 50% self-consumption @ 70% self-consumption @ 50% self-consumption 70% self-consumption
~5 year payback ~4.1 year payback ~4.9 year payback ~4 year payback
~19% IRR ~24% IRR ~21% IRR ~25% IRR
~$700 annual savings ~$860 annual savings ~$1,170 annual savings ~$1,430 annual savings

Calculate indicative solar power system ROI & payback periods for Perth, WA

calculator iconLet Solar Choice help you find solar deals in Perth

Solar Choice, as Australia’s free Solar Energy Brokering and advice service, connects solar PV customers with installers who service their area. We provide comprehensive quote comparisons of solar power installations throughout the country–including in Perth. With a bird’s eye view of the solar power market, Solar Choice is uniquely poised to identify the best deals on offer and facilitate our customers to find the solar system that best suits their needs and budget.

Request a Solar Quote Comparison today by filling out the form to the right of this page, or call us on 1300 78 72 73.

© 2016 Solar Choice Pty Ltd 

(Top image via Wikipedia)

{ 10 comments… read them below or add one }

Ken Stranger June 1, 2012 at 7:19 pm

I am curerntly researching the advantages of Solar in the current scheme of rebates etc and (please correct me if I am wrong) the following statement in the text of your web site I would find hard to believe because you would have to be cosuming all the power during the core sun hours of the day – most households I would expect have highest consumption outside the hours of the solar generated power. So to say a 5Kw system “just about covers the daily consumption” I would suggest is misleading.

Quote” Household demand varies by the size of family and the appliances used and how frequently, but as a ‘base case’, the average 3-person home uses 20kWh per day, averaged over the course of a year. This means that with a 5kW solar system, the home’s energy consumption is just about covered by the system’s output”

Reply

admin July 26, 2012 at 8:12 pm

Hi Ken,

Yes, you’re right that that information could be misinterpreted, so I’ve changed the wording. If there is a Feed-in Tariff (which there no longer is in WA), it could be possible to offset your entire bill with a solar PV system. However, in the absence of such a scheme, it is necessary to instead ensure that all the solar power is being consumed as it is being produced–otherwise you are ‘wasting’ the power by letting it go into the grid for 8c/kWh. The system does still, however, afford significant benefit to those looking to reduce their electricity bills.

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Tom Slaiter February 6, 2013 at 11:18 pm

Do you have any other calculators? Will the one for Perth work anywhere else?!

Great post, thanks a lot :-)

Reply

Solar Choice February 19, 2013 at 11:16 am

Hi Tom,

The Perth calculator will essentially work for the whole of Australia, the Perth specific data is the system price which comes from your Solar Quote Comparison. If you put in all your details you will get a price for systems in your area, you may also need to change the average sunlight hours for your state or area.

We have specific calculators for different states and system sizes which you can check out by searching ‘ROI’ on our website.

Hope this helps

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Peter Mansey September 10, 2014 at 1:26 pm

I am researching the installation of solar for my Perth WA home and in this regard I want to make sure that I engage a reputable retailer. Whilst price is important the lowest price quite often does not represent value for money (the non reputable retailers being the culprits). How do I know that your comparator only delivers results of reputable value for money retailers.
Further I note in your advice that the average three person home uses 20kwh per day, is this a 24 hr day or consumption during daylight hours. If it is the former then the figure to me is meaningless noting that solar panels do not produce at night. I would be more interested in the avg consumption figure for daylight hours only. My intention is to have a system that produces enough on average over the course of a year that will offset the kwh I use during the day. In short not looking to make money rather just want to reduce my chargeable consumption.
I have another query. Been reading your Perth WA comments and I note that you state that Perth gets an average of 4 hours of sunshine a day. I assume that you use this figure to determine a system size. I think your figure of 4 hours is incorrect. The Bureau of Meteorology website stats advise that the 94 year average for Perth is 7.9 hours. What impact does this fact have with regard to system requirements.

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Solar Choice Staff September 16, 2014 at 5:50 am

Hi Peter,

Thanks for commenting. You bring up some good points.

As for installers in the Solar Choice network: there is a high level amount of due diligence that takes place before bringing any installer on board. In addition to ensuring that all of our installers are accredited through the Clean Energy Council, we also conduct review of the website, product on offer, past installs (quality and volume) and length of time in business are all taken into consideration initially. Pricing, locality and customer reviews/perception are then all looked at before we take an installer on. Each installer’s information is also instantly displayed for our customers as soon as the “Submit” button is pressed on our Solar Quote Comparison request form and we would encourage all of our customers to complete their own research to help make a decision.

About the 20kWh/day household usage figure, you are correct that this is for 24 hours, and only a portion of electricity consumption for a given home takes place when the sun is shining. Actual daytime household consumption will differ depending on the home in question. Our Solar PV Payback Calculator takes this fact into account–you can set your household’s ‘self-consumption’ as a percentage. We encourage all of our customers to make sure they understand what they can expect from a system before they put their signature on a contract–and this means looking at daytime electricity consumption and usage patterns (we’ve written about this topic here.)

Finally, about the 4 hours of sunshine–I’ve actually just updated the article (based on your feedback) to be a bit more accurate. In Perth you can expect 5.2 ‘peak sun hours’ per day, averaged throughout the year. Peak sun hours (PSH) are different from sunshine hours as listed by the BOM–they’re a technical measure used in the solar industry when talking about solar power to indicate hours of ‘peak’ sun. While Perth may indeed get 7.9 hours of sunshine throughout the day on average, the power of this sunshine is not equal throughout the day when looking at it from the vantage point of a fixed solar panel array.

If we’re talking about a north-facing panel array, the sun is weaker in the morning, strongest in the afternoon, and then weaker again as the sun is going down. When you compress these various degrees of sun strength into uniform units (PSH), you come out with about 5.2PSH for Perth. If you have 1 kilowatt (kW) of perfectly efficient solar panels, and you shine 5.2PSH on them, you will get (1kW x 5.2PSH =) 5.2kWh of solar electricity.

The 4 sunshine hour figure was not technically correct–it should not have been sunshine hours of input, but rather kWh of output. To explain further: A solar PV system is never perfectly efficient; it is realistic to expect about 80% efficiency from a typical solar array. If the total nameplate capacity of your array is 1kW, and you live in Perth (where you can expect 5.2PSH per day on average), then in a ‘100% efficient’ scenario, your system will produce (1kW x 5.2PSH =) 1kWh of electricity. Once we apply the 80% to this figure, we get down to about 4.16kWh, which is a more realistic expectation for a well-designed and optimally installed system. This is where the original 4kWh figure came from. Applying this 80% efficiency derating to a 5kW solar system, we would get (5kW x 5.2PSH x 80% =) 20.8kWh.

Hope this helps! Feel free to get in touch if you have any more questions.

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John December 13, 2014 at 11:40 am

Hi

I am enjoying reading your website and only wish I had made some better decisions based on your information.
I built a new home in the south west of Wa in 2012/13, during construction I invited 2 solar pv companies to price a 5kw system for our new home. Both were negative and we did not proceed believing it was a hopeless case. The house is 2 storey, skillion roof with10 degree pitch which faces due west.
After attending a sustainability seminar last week in Perth I get totally different advice that I will lose approx 15% efficiency only!! And it’s still well worth doing. We just want to decrease our synergy bill more than anything, we have roof and wall insulation, solar heat pum hot water service, ceiling fans, full led lighting and excellent cross ventilation design with louvred. I find that heating is more the issue than cooling as we do not have access to mains gas we have reverse cycle aircon.
Is a battery system worth investing in ( more due to cost and lifecycle of batteries)
Thanks for your time
Confused

Reply

Solar Choice Staff December 16, 2014 at 1:09 pm

Hi John,

Thanks for your comments. We’ve definitely noted before that west-facing roofs are a good options for homes that don’t have an unobstructed northerly aspect.

As far as energy storage is concerned: systems are steadily becoming more affordable and more and more homes are seriously considering them, but we are currently advising folks to wait until they find a deal that makes financial sense. A solar PV system without energy storage, if sized appropriately (i.e. to meet the household’s electricity needs) should have a payback period of under 7 years in most parts of Australia–4 or 5 is not unheard of. We’d only recommend going with energy storage if you can find a system that is comparable to that.

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Ann Boyer January 13, 2016 at 4:55 pm

Microinverters versus say a Frontius regular inverter – how reliable with heat problems? Perth Temperatures get very high in summer. I understand the advantages but . . .

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Solar Choice Staff January 20, 2016 at 3:21 pm

Hi Ann,

I’ve reached out to both Fronius and Enphase (the world’s biggest microinverter manufacturer) to get a response to your question. Below are the comments they sent to me:

From Fronius:

All decent inverters have temperature sensors, which are designed to protect the inverter from heat related failures. They also have been tested to hot Australian conditions (like Fronius inverters have).

The main problem for microinverters is that they are mounted on the roof with only the shade of a solar panel to protect them. Australian tin rooftops can easily get to 60 – 70 degC on a hot summer’s day. If you check out the datasheets of most microinverters, they will start derating their power output at 65 degC and will totally shutdown at about 85 degC. Fronius string inverters, for example, are mounted in much cooler locations out of direct sunlight (say on the south wall of your house) in an ambient temperature environment so they have a much easier life. When power electronics are involved, it’s best to keep out of the heat!

Also, as we always mention, reliability is not just about the product not failing but how you get the system back up and running. See white paper attached from our colleagues in the US.

Micro inverters even if reasonably reliable under heat conditions have a problem when it comes to service and maintenance vs Fronius inverters due to their scaling limitations.

(You can download the Fronius Whitepaper here.)

Enphase referred me to a paper from their ‘Mythbuster’ series (which you can download here). Below is an excerpt from this paper. If you’d like more details, please see the document itself.

During the summer of 2014, extreme heat took a heavy toll on Australia, sparking bushfires and melting tar in the roadways. For three scorching weeks, Enphase closely monitored over 2,000 microinverters. None of them shut down because of the heat.

Enphase Microinverters cope with these conditions for two reasons. Our engineers have designed them to maintain a low thermal footprint, and our installers have kept them away from direct sunlight and heat from the roof.

When Australia needed renewable energy the most, Enphase Microinverters delivered.

Reply

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