Solar energy FAQs
Solar energy isn’t as complicated as you might think. But understandably there are a few questions that we often get asked. To find out information about specific installation options, contact us here.
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What is a solar electricity (photovoltaic) system?
A solar photovoltaic (PV) system is made up of solar PV modules, an inverter, racking and wiring.
Solar PV systems work very simply to provide a household or commercial structure with usable, renewable, clean green energy.
Flat solar PV panels are mounted to a roof and convert energy from sunlight into direct current (DC) electricity. A device called an inverter then changes the DC into alternating current (AC) electricity, which can be used for a household's electrical needs such as lighting and operate appliances.
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How does a solar PV system work?
When sunlight hits a solar PV module, direct current (DC) electricity is produced and the inverter changes the current from DC to 240V alternating current (AC). This electricity can be fed into the National Electricity Grid (grid) or used immediately within the home.
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What is the National Electricity Grid?
The National Electricity Grid is the network of wires that delivers electricity from generators to homes and businesses around Australia. When you install a solar PV system you become a generator of clean renewable energy.
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What is the difference between a solar hot water system and solar PV system?
A solar hot water system uses the sun's warmth to directly heat water.
A solar PV system converts sunlight into electricity for use in the home or to be fed into the electricity grid. The heat output of the sun is not important for solar PV systems, but the amount of sunlight available is.
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What are the different types of solar PV panels?
There are many different types of solar PV panels currently on the Australian market. The three main types are monocrystalline, polycrystalline and thin film panels.
A range of materials can be used to produce a PV panel. The most common is silicon and this is the oldest PV technology available. But there are newer technologies which are proving to be effective in Australian conditions.
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Does the orientation of the roof affect whether or not a home can successfully install a solar product?
Although it is optimal to install solar products on the north-facing side of a roof, it is also possible to install a solar PV system on the east or west facing side of a roof, as long as there is sufficient space. However, this will not produce the same results as a north facing installation.
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Is mains electricity still needed?
Yes, mains electricity is still needed because solar PV systems only produce electricity when they are exposed to sunlight. When there is no sunlight, no electricity is produced, so you will need to draw electricity from the grid (as you currently do).
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Are batteries needed for the solar PV grid connect system?
No. Grid connected solar systems do not store electricity – instead, any electricity you do not use in your home is 'exported' to or fed into the electricity grid.
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Is it possible to increase the size of a solar PV system in the future?
This depends on your roof space and the size of the inverter. If you have sufficient roof space and additional capacity in the inverter you could increase the size of your system. Or you could add a second system to your roof.
At this point the solar feed-in tariffs in each state have limits on the system size which they apply to. AGL's solar specialists can assist with this information.
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What happens at night?
As solar PV systems only produce electricity when they are exposed to sunlight, they do not produce electricity at night. At night you will use electricity from the electricity grid, as you currently do.
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What happens on cloudy days?
The performance of the Solar PV system is affected by cloud. When there is not enough light to produce electricity, you will use electricity from the grid, as you do now.
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What will happen during a blackout?
For safety reasons, in the event of a blackout, your solar PV system will stop producing electricity. This safety measure is mandatory and has been put in place to protect anyone working on the blacked-out grid system. As soon as the grid is back online, your system will be restored.
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Where do residential solar PV panels get placed?
Our experienced site assessors will determine the optimal position for your solar PV system. There are many factors to take into consideration when planning the placement – from orientation to the sun, to area available and distance to the meter. In an ideal situation, the panels would be oriented as close to north facing as possible, in an area with no shading.
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Is it true that solar electricity systems are more efficient inland rather than on the coast?
There are many factors affecting efficiency. Inland regions generally have fewer cloudy days than the coast. Conversely, high temperatures, smog and dirt are more prevalent inland and can also affect performance.
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How much electricity does a solar PV system produce?
There are a number of factors that will affect how much electricity a system will produce. The orientation of the panels, where you live in Australia, any shading of your panels and the amount of sunlight on a given day will all affect how much energy the solar PV system produces. Under optimal conditions, a 1.5kW solar system can produce around 2,182 kWh in Sydney*.
*Estimated output is based on a 1.5 kW First Solar system and is dependent on factors such as solar radiation, location, system degradation, and system efficiency. Output assumes a north facing roof pitched at 20-30 degrees with no shading.
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What are Renewable Energy Certificates (RECs)?
RECs are part of the government's commitment to renewable energy. Each REC represents 1 MWh (Megawatt hour) of energy produced. RECs are created when you purchase qualifying solar hot water, solar/wind power systems or residential solar PV systems.
RECs have been devised as the means for Australia to meet its 2020 target of 20% renewable energy.
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How much are RECs worth?
The value of the RECs you are eligible for varies depending on your location (and zone rating), the size of the system you install and the market for RECs. AGL's solar estimator can advise what your approximate savings are likely to be.
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Do I have to sell my RECs as part of installing a solar system bought from AGL?
Yes, the price of the solar energy system is dependent on you assigning your RECs to AGL. There is no alternative pricing for AGL's solar systems should you wish to retain your RECs.
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What is a feed-in tariff?
A feed-in tariff is the rate paid for any electricity your solar PV system generates and feeds back into the grid. The rate which is paid varies depending on your state.
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Gross versus net feed-in tariffs
A net feed-in tariff pays the solar PV system owner only for surplus electricity they produce but haven't used.
A gross feed-in tariff pays for each kilowatt-hour produced by the system regardless of how much is used by the residence/building. The feed-in tariff schemes are set by the state governments and vary between the states.
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Will it affect my property resale value?
When you purchase a solar system, all of its benefits, including the warranties and electricity savings, are linked to the property. Even if you move, all warranties will remain with the system, meaning that the new owner will receive the benefits.
There is not yet enough data to accurately predict the level of an increase to property prices.
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Are the solar rebate and feed-in tariff payments taxable income to a customer?
AGL is not able to provide advice as to whether or not particular income or payments are taxable by the Commonwealth Government.
Customers should consult their accountant or the Australian Taxation Office for advice as to whether payments are taxable in their particular circumstances.
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Is GST payable on feed-in tariff revenue?
AGL is not able to provide advice as to whether GST is required to be paid. Customers should consult their accountant or the Australian Taxation Office for this advice.
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How are the feed-in tariff payments received?
Feed-in tariff payments will appear as a credit on your AGL electricity bill.
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What happens to participating NSW customers' regular electricity bills?
The Federal Government announced that "from 1 July 2010 onwards, a bill issued to an eligible small retail customer is required to include the amount of electricity supplied to the network during the billing period and the amount to be credited for that electricity".
Customers should be aware that they may not be eligible to receive the Solar Bonus Scheme credit and relevant details on their electricity bill until 1 July 2010. Over the first six months of the Scheme, the amount a customer receives on their bill will depend on the applicable transitional arrangements.