Solar Power FAQ

Solar Power FAQ


We have compiled this list of solar power FAQ to answer specific questions, as well as to help you browse various topics to deepen your understanding of the technology involved, the solar industry in general and why it is so important to use a reputable solar panels installer such as Solaray.

Solaray has an extensive track record of supplying and installing quality Solar Systems, whilst providing the best customer service levels available in the industry today.

We selected our products to provide the best combination of efficiency, performance and value for money. This, together with our customer service approach and rigorous installation standards, means you can have confidence that a Solaray System represents the best available and cost effective solution on the market.

How Much Power Does A Solar panel system Produce?

A 2kW system should output on average 7.8 kWh per day, and a 10kW system 39 kWh per day. Using this figure, a simple yet effective way to estimate the output of a solar system that is installed is to multiply the system size by 4. For example, a 2kW system will generate approximately 8 kWh of power on an average day.

However, it is important to note that output varies considerably across the year as there is on average more sunlight during the summer months compared to the winter months. The sun is much lower in the sky in winter. Thus, the output your system produces at different times of the year experiences direct impact by the angle of your solar panels. More information on this here:  Should I Get Tilt Frames For My Solar Panels? The numbers on this graph are the estimated output for a 5kW solar system across the year:

Is Solar Power Worth It?

Good quality solar power systems have never been so affordable. This year we will see many households add battery storage to their system to store excess solar power that can be used in the evening. Tesla is a leading producer of solar batteries. We are now installing 410W-430W solar panels,  a huge improvement from the standard 250W panel we were installing only a few years ago. If you have been considering solar, this is the year you should seriously consider getting a solar power system installed.

Let’s answer these questions to help you work out not only if solar power is worth it but what size system will be the best fit for your household.

Solar Power Rebates in NSW- How it all works

There has never been a better time to buy a solar power system in Sydney or Melbourne. System prices continue to fall and great incentives are still in place for eligible households. In NSW there are two main financial incentives for installing solar panels:

  • Small Scale Technology Certificates– which can be used to reduce the purchase price of your system.
  • Feed-in tariff– an agreement with your energy retailer whereby you are paid for the excess solar power that you feed back into the grid.

In Victoria there are also incentives in the form of interest free loans.

Small-scale Technology Certificates (STCs)

Small-scale Technology Certificates (STC’s), previously known as Renewable Energy Certificates or RECS, come about when a Renewable Energy System such as a Solar PV system is installed.

The number of STCs depends on the size of the system and therefore the amount of energy generated. In essence, one STC is created for every megawatt-hour of production capability of the system. In simplistic terms, a 2kW solar system would be expected to generate between 2.4MW and 2.9 MW per year depending on location.

This is further multiplied by the number of years the system is likely to generate energy. For home solar systems, this is usually 15 years, although the life of the solar panels themselves is considerably more than that.

System Output STC’s Rebate*
5kW 80 $2,880
8kW 125 $4,500
10kW 150 $5,400

* Based on an STC price of $36. Contact the Solaray Team for the latest STC price.

What does this mean for me?

Your solar power installer will normally reduce the purchase price of the system by the value of the STCs created by your system. There is no additional paperwork, and you receive the value of the STCs at the current market price.

STC Price

The system for trading and pricing STCs for small systems is managed by the Small-scale Renewable Energy Scheme (SRES).

STCs are bought by Liable Parties (usually electricity retailers) and must be surrendered at the end of each quarter. As the number of STCs that are required to be surrendered is a fixed amount each year, but the number of STCs created is variable, the price paid for STCs also varies and is determined by supply and demand.

The Federal Government legislated in 2010 a fixed price for STCs by implementing a Clearing House system where STCs can be bought and sold for $40. However, there is no requirement for Liable Parties to purchase from the Clearing House, so they are likely to only do so if there is a shortage of STCs or the market price exceeds $40. There is currently a surplus of STCs in the market which means the market price of STC’s below $40.

Feed-in Tariff

In NSW, all new grid-connected solar systems have Net Metering, where the solar power that is generated is fed into the home to help reduce your reliance on the grid. Because electricity is used immediately, any power that is not used in the home is automatically fed out to the grid. This power is bought by your energy retailer and you earn a feed-in tariff, which is reflected on your power bill.

The Independent Pricing and Regulatory Tribunal has stipulated that a fair and reasonable value for excess solar power exported to the grid is in the range of 7.7 to 12.9 cents per kilowatt-hour. For example, if you have a 5kW system and you export all of the power to the grid on a typical Sydney day, you will receive a credit of approximately 20kW/h x 8c = $1.60.

What happened to the old 60c feed-in tariff?

The 60 cent feed-in tariff was a part of the State Government’s Solar Bonus Scheme that closed to new applicants in 2011. These systems have Gross Metering where all of the solar power is fed directly into the grid and households are paid a feed-in tariff for all of the power generated. At the time, residential solar power systems were prohibitively expensive to install. However, this state rebate was extremely successful in encouraging households to install solar systems and help grow the solar industry. As a result, we have seen a dramatic reduction in the cost of installing a solar system.

Does solar power work on cloudy days?

A solar system does not only work only at maximum capacity. In low light conditions such as early in the morning or when it is overcast, solar panels will still convert light into power for your home, just at a reduced rate.

For example, a 4kW system may only output 2kW of power on a cloudy day. There is a point where the energy produced is no longer strong enough to power the inverter and the system will turn off. This happens every evening and perhaps during an especially dark storm.

Here is an example of one of our high performing Enphase Micro Inverter systems on an overcast day. As you can see output can change minute by minute as the sun comes out and disappears again behind the clouds. This system is orientated just west of north so the peak solar output occurs from late morning through to around 4 pm in the afternoon. This is an early spring day (September) so the peak output period will increase in length over summer, and be a little shorter in winter.

Enphase North West Output

What is a kilowatt hour (kWh)?

This is a unit for measuring energy and it is how your energy retailer bills you. A kW/h is one kilowatt of power measured or used over an hour. For example, if you have an air conditioner that uses 3kW of power, it will use 3kWh  power every hour. If you are billed 25 cents per kWh by your energy retail, it will cost you 75 cents every hour to run the air conditioner.

Similarly, a 2kW solar system will generate 2kWh of power for every hour that it is outputting power at full capacity. If on a sunny day in summer it works at full capacity for 4 hours and you use all of this power in the home, you will save $2.00 on your power bill (2kW x 4 hours x 25 cents).

How much power will my solar system generate?

This depends on a number of factors including your roof orientation, the angle of the panels, the weather, the seasons and the size of your system. Because of this we only use averages as well as guidelines from the clean energy council.

The Clean Energy Council advise that in Sydney a solar system should on average output 3.9 kWh of energy per day for every kW of solar installed. This takes into account the seasons and the weather. On any given day this figure could be extremely different.

To simplify this further, a 2kW system should output 7.8kWh per day and a 10kW system 39kWh per day Using this figure, a simple yet effective way to estimate the output of a solar system that is installed is to multiply the system size by 4 (or 3.9 to be exact). For example, a 2kW system will generate approximately 7.8kW/h of power on an average day.

As with most products, our experience is that higher quality products in many cases achieve results above the expected averages.

What size system do I need for my house?

The right sized solar system for your household depends on what you want your system to do. For many people, it is about making sure it pays for itself in as little time as possible, for others it is to reduce their power bill by the greatest amount possible or to reduce their carbon footprint to do their bit for the environment.

Paying back your investment as quickly as possible requires sizing up a system to match your daytime energy usage. In a perfect situation, you would use all of the solar power that is generated and have the solar panels facing north or (north-west to maximise your savings during the peak time of use billing period- see below for more info).

For example, if you install a 5kW system for $6,200 and it generates 7118kW/h over one year if you save an average of 30 cents a kW you would save $2,135 every year. This would result in a return on your investment of only 2.9 years! In reality, it is difficult to use 100% of the power a solar system generates, however, if the system is sized correctly you should be able to get close to 80% and higher. Minimising your power bill is easy, simply buy the largest solar system you can afford and/or fit on your roof. As mentioned above, there is a good fit for everyone but there is no harm in getting a system that is a little bigger.

What if my solar energy needs grow?

This can allow for future increases in power usage if you are planning on buying a pool, spa, air conditioner or some other large user of power, and don’t forget the kids! For some reason, teenagers seem to find it difficult to shower without the heat lamps on, and then there is the hairdryer… The reason returns diminish when you have a larger system is that instead of saving money from your bill by using the solar power rather than buying power from the grid (eg. contracted rate of 25 cents per kW), you are selling solar power to the grid at your contracted feed-in tariff rate (eg. 7 cents to 10 cents per kW/h).

If you are environmentally motivated, your roof space and your budget are all that are stopping you! The bigger the solar system the better. You are reducing your reliance on polluting industries such as coal and gas and helping to produce clean, renewable energy. Buying a solar system is one of the biggest steps you can take as an individual and a household to help build the renewable energy sector and reduce our reliance on old and polluting technology

There are now millions of solar systems in Australia, and as this number continues to grow our voice becomes louder- governments are starting to listen!

What direction should my solar panels face?

Solar panels will generate the most energy over the course of a year when they are facing north. This is especially important in winter when the sun is lower in the northern sky. A Solaray consultant can visit your home and, using specially designed software, demonstrate the sun and/or shade that your particular roof will have in winter, summer and at any time during the year. If your house has a north-south roofline, we can install panels on either the eastern or western roof depending on what time of the day you use the most power.

For many families, they will use more power in the afternoon when the kids are home from school and the air conditioner and pool pump are running. If this is the case we would install your solar panels on the western roof. The other point that can influence this decision is time-of-use pricing. Please see the question about your new digital meter for more detail. It is important to understand that panels installed on a roof facing south of either east or west will generate significantly less power than a solar system facing north, and may not even turn on during winter. In almost all cases, we would advise against using any south-facing roof as it is not only against industry best practice but also as your financial benefits may be below an acceptable level.

Do I need a new digital meter?

Yes, all solar systems require the replacement of your meter to a new digital meter that can monitor how much power you send to the grid as well as how much power you buy from your energy retailer. If you have a digital meter you will still need a replacement meter as it will not have the correct programming in it. This is unless you or your builder specifically install a bi-directional meter. This is rare for houses that have not had a recent renovation.

Does having a digital meter mean I will pay more for my power?

Your new energy tariffs will then depend on which energy distribution area your house is in. If you are in the Endeavour Energy distribution area, your regulated energy tariffs should not change when you go solar. In the Ausgrid distribution area, having a new digital meter will result in you being charged time of use pricing. This is a great opportunity to further reduce your energy bill but you will need to manage your power usage to ensure you maximise the potential benefits. Energy prices in the shoulder and off-peak periods are much cheaper than a flat-rate tariff.

The peak billing period is between 2 pm to 8 pm on weekdays only, which means you will pay less for your power 82% of the time. According to Ausgrid, an average Sydney household only uses 22% of their power during the peak period, when power prices are approximately 50 cents per kW/h.

If you have a roof facing between north and west, you can take advantage of time-of-use pricing to further minimise the amount of power you use during the peak period. This results in both free solar power in the afternoon and low tariffs in the morning until 2 pm and after 8 pm. Please note that the actual tariffs you pay depend on which retailer you choose and the available packages. If you have any questions about this please call us now on 1300 525 451.

I have heard that solar technology is progressing rapidly. When should I look at getting a solar system installation?

Now is the best time to buy a solar power system in Sydney or Melbourne due to generous government rebates and a high Australian dollar. It is important to remember that no matter how efficient panels become in the future, a 3kW solar system is always going to output 3kWs.

A common mistake consumers make is to equate a panel’s efficiency with its output. A high-efficiency 350W panel produces exactly the same power as a low-efficiency panel, it just does so using a smaller surface area. Unless you have limitations from a small roof or you are looking to install a commercial size solar system (over 30kW or so), efficiency is largely irrelevant. You would be much better off buying a 5kW system with today’s 400W panels compared to waiting 5 years to buy a 5kW system with 450W panels because you can take advantage of the great government rebates currently available. Plus you have had lower power bills in the meantime! Solar power prices have been dropping for many years. However we are approaching a limit to this price drop due to the fixed costs of installing a system such as the installation, cabling and mounting kit.

Do you offer payment options?

Yes, we offer a number of great options depending on what you are more comfortable with. We offer an interest-free payment plan for all of our systems using Certegy Ezi-Pay. The minimum deposit is 10%. However, you can put down more if you want to reduce your repayments and payments are made fortnightly.

All you need to apply is an Australian drivers licence and over 96% of applicants get approval instantly. As always, conditions apply, so please call us for a quote and for the terms and conditions. A solar system from Solaray qualifies for a low-interest Green Loan. This is available from local credit unions.

The interest rate can be as low as your home loan. We are not able to offer financial advice, however many of our customers are now taking advantage of this offer to finance their solar system. We are happy to make an introduction to the appropriate credit union as a Solaray customer.

If you are looking to pay for your system in full, we require a deposit (usually $500 on a standard system) and the balance on the day of installation once the solar system is fully installed. Speak to our staff today about our great discounts available if you are looking to pay for your system upfront. And yes, this discount is available if you organise your own finance through a green loan!

What maintenance does a solar system require?

Very little. Solar panels are passive. However, they can collect dust, bird poo and other particles that will build up over time. Luckily the rain will normally wash all of this off. If there is a period of many months without rain, by all means safely wash your solar panels by spraying them with a hose. Do this whilst standing safely on the ground. We don’t recommend that you go up onto your roof and wash them by hand. It is not worth your time and of course, it can be dangerous. If you get up onto your roof to clean the gutters then spraying your panels could be a good idea if you are able to do it safely. We have heard of other companies charging yearly service fees to maintain your system. However, why pay for something you don’t need?

What happens if there is a blackout?

For safety reasons, your solar system switches off in a blackout. It should automatically turn on again once the power is restored. If it doesn’t, visit our Service Centre page for troubleshooting tips on resetting your system. If Solaray installed your system, and the issue persists, you can submit a Support Ticket request from there. We can help you switch your system on again or book a service check for you to make sure everything is ok.

If another installer installed your system, we suggest you reach out to them, or to the inverter manufacturer.

I have 3 phase power. Do I need a 3 phase inverter?

Not always. A three-phase inverter directs power across all 3 phases evenly. However, you can also have a standard inverter and not adversely affect your returns because your new digital meter will usually reconcile the power across all three phases in 15-minute increments. Whether or not you need a 3 Phase Inverter really depends on the size of your system, your load and usage profile and future plans. please contact our solar staff so that we can assess what you have in your home and then provide you with the right information.

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