Frequently Asked Solar Questions

  • How does a solar power system work?
    When the front facing surface of PV solar panel(s) are exposed to sufficient levels of sunlight, i.e. solar radiation, a DC electric current is produced. For PV grid-connected power systems, this DC solar generated current is fed into an inverter and converts it to AC current. The AC current then powers AC loads connected directly to the PV system, while any surplus AC power is exported onto the main electricity grid.

    In standalone PV system configuration, there is no electricity mains grid. If the system powers AC loads, then an inverter is used as well. Common to both AC and DC standalone PV systems is the battery bank which stores excess PV generated energy for later use such as at night time, or during extended periods of bad weather.

  • What is PV?
    PV is an abbreviation of the word photovoltaics (photo=light, voltaics=electricity), and refers to semiconductor-based technology that is used to convert light energy directly into electricity. There are no moving parts, no consumption of fuel, and is pollution free.

  • What is an inverter?
    An inverter is an electrical device that converts DC current to AC current.

  • Will our building be suitable for a solar system?
    It depends on several aspects that need to be evaluated to determine if your building is a good site for solar. These include: orientation, available space, shading effects. The best sites in the Southern Hemisphere will generally have a north-facing roofs perspective and free of shade. The opposite is true for the Northern Hemisphere sites.

  • Where else can the solar panels be placed?
    Solar panels can be deployed just about anywhere it can receive direct and unimpeded sunlight all year round.

    For best electrical performance, solar panels should be positioned at their optimum angle facing the equator. The optimum angle is generally determined by the degree latitude of the solar site. The north side of a roof in the Southern Hemisphere, and vice versa for the Northern Hemisphere.

    Solar panels can also be mounted on pergolas, sheds and verandas, as long as they can support the panels safely, and where the panels can be angled toward the sun. The inverter(s) are generally installed close by to minimise electrical cable resistance losses.

  • What will a Grid-connect system power?
    Your Grid-connected system will directly feed into your home's internal electrical grid, and hence all home appliances receive the PV system's power. The amount of PV power delivered to the home appliances depends on the instantaneous power being produced by the PV solar panels at the time. If there is insufficient power from PV, then the electrical grid supplies the balance.

  • Who installs the system?
    Registered installers that have grid-connect qualifications, accredited by the Business Council for Sustainable Energy (BCSE) and are also licensed electrical contractors. To be eligible for the rebate, your system must be designed and installed by a BSCE grid-connect accredited designer and installer.

    The installer must personally sign off on the installation report upon completion of your system. SilexSolar recommends only accredited installers be used to install the solar system.

  • How does the weather affect the system?
    Yes, weather conditions will affect the system. Every PV solar system's energy output is subject to the instantaneous variations in solar radiation. On a cloudy day, the panels will produce electricity, however the production will not be as high as when the panels are in bright sunlight. The PV system's long term performance varies seasonally. The situation can be further complicated if there is periodic shading caused by trees, buildings and other features which may interrupt the path of direct sunlight onto the panels.

  • What maintenance is required?
    A grid connect system requires very little maintenance. The solar panels may from time to time need cleaning. Always observe all Occupational Health and Safety requirements such as working from heights, e.g. roof mounted systems. When solar panels are tilted 15 degrees or more, rain run-off can help keep them clean, however, local conditions will ultimately dictate the frequency and degree of cleaning.

  • What happens to the Grid-connect system during a blackout?
    For safety reasons, the grid connect inverter automatically shut itself off during a blackout, so as prevent back feeding the grid. The system switches off until mains electricity is restored.

  • Can I expand the size of my Grid connect system at a later date?
    Yes, provided the existing inverter's ratings specifications can accommodate the larger solar array, Also there are many other practical design considerations that need to be taken into consideration on a case by case basis.

  • What are the warranties?
    Refer to specific warranty terms mentioned elsewhere on the website. In generalised terms however, SilexSolar offers a 5 year mechanical defects warranty, and a 25 year minimum power warranty. The full terms are as per current industry best practice.

  • Are solar panels covered within my insurance policy?
    SilexSolar can only recommend you contact your insurance provider to get the PV solar system added to your home policy.

  • How does solar help the environment?
    Yes, solar helps the environment. For every 1MWh of PV solar energy produced by your system, this alleviates the need to burn fossil fuels which release approximately 830kg of CO2 green house gas equivalent.

  • What are the environmental benefits of using renewable energy?
    The ultimate goal for renewable energy is to provide the world with a sustainable, affordable and clean source of electricity.
    In the case of PV Solar energy, there is minimal pollution and positive impacts on the environment in various ways by:

    » Reduces the depletion of fossil fuel reserves and the environmental damage resulting from fossil fuel exploration and extraction.
    » Renewables avoid and reduce green house gas emissions due to carbon dioxide, nitrogen oxides, and sulphur oxides.
    » Improves air quality and visibility due to decreased burning of fossil fuels, particularly coal and oil.
    » Solar energy is silent, produces no waste or pollution, therefore limiting your impact on climate change and global warming.

  • What are the financial benefits?
    The price of energy is rising rapidly, and it's inevitable that the future cost of conventional fossil fuelled energy is going to continue. Renewable energy provides a long-term solution to this global problem of escalating fuel prices.

    How does solar help the environment?
    Yes, solar helps the environment. For every 1MWh of PV solar energy produced by your system, this alleviates the need to burn fossil fuels which release approximately 830kg of CO2 green house gas equivalent.

    PV systems can be located just about anywhere. Their great advantage is that they can not only be installed as large centralised power plants, just like conventional power stations, they can also be installed and distributed as micro generating power stations such as domestic systems on the roofs of houses all over the country and cities. This has the added economic benefit in that PV can be produced at the point of consumption.

    With the assistance of government incentives that aim to stimulate growth in the PV industry and drive costs down to ultimately reach "grid-parity", the affordability, i.e. economics of PV, based on initial investment and ongoing operational costs is being more attractive day by day.

    Solar power increases the value of your home, and will save you money on your power bill.

    A PV Solar system on your house (or even business), sends a clear message to your neighbours and the general community at large that you are concerned, but most importantly taking real action about your own social and environmental responsibilities.


Questions and Answers

Who will buy my excess energy?
Your electricity retailer will purchase the surplus power produced from your solar power system. The policy environment for the generation and purchase of renewable energy both federally and state is currently evolving. Contact your electricity retailer for buy back rates.

What is a feed-in tariff?
A feed-in tariff is the rate (in cents per kWh) your electricity retailer is obliged to purchase electricity from your PV system. There are two types:

Gross Feed-In-Tariff, and Net Feed-In-Tariff. Gross Feed-In-Tariff is the most generous scheme, whereby the electricity retailer must pay the PV system owner (e.g. the householder) for the total i.e. Gross kWh of PV energy produced by the PV system.

A Net Feed-In-Tariff on the other hand is a far less generous incentive. The electricity retailer pays only for the PV generated electricity that is surplus, i.e. not consumed by the home owner, and hence the Net electricity exported to the grid. The precise nature of the Feed-In-tariff in your location may vary. However, there will be a wealth of information on internet web sites, In the first instance, contact your electricity provider, PV installer, and or Government department for up to date details.

How much will it cost to run?
There are no running costs.

What sort of panels should I buy?
There are four main types of solar panel available, each with their own benefits. During the design and specification stage, your accredited designer will help you choose which type is the best to suit your needs:

1. Mono Crystalline (monocrystalline c-Si)
These panels are a proven technology that has been in use for over 50 years. They have the highest efficiency of 12-15% in the real world, meaning that fewer panels are required to produce a given amount of energy. They are commonly used where space is limited, or where there are high costs associated with installing large panels
They have a very slow degradation, generally losing 0.25 - 0.5% per year..
2. Poly Crystalline (polycrystalline c-Si)
These panels are similar to Mono Crystalline panels, but the silicon used is Multi-Crystalline which is easier to make. They are comparable to Mono Crystalline in performance and durability, except their efficiency is slightly lower, generally 11-13%. Slightly more panels are required to produce a given amount of electricity.
3. Thin Film
These panels have a lower efficiency of 5-6% so the panel is typically nearly double the size than the other panel varieties. Research is continuing to improve the performance of Thin Film panels and to refine the manufacturing process. They respond well to slightly diffuse light and their efficiency does not drop on hot days. The most common varieties of Thin Film panels are:
» Cadmium Telluride Thin-Film panels (CdTe) Ongoing research has resulted in CdTe panels with an efficiency of up to 11.2%. These panels are manufactured by First Solar.
» Copper Indium Gallium Selenide Thin-Film panels (CIGS)
» Amorphous silicon Thin-Film panels(a-Si)

What angle should the solar panels be on?
Solar PV panels produce most power when they are pointed directly at the sun. In Australia, solar modules should face north for optimum electricity production. The orientation of the panels will often have a greater effect on annual energy production than the angle they are tilted at. A minimum tilt of 10° is recommended to ensure self cleaning by rainfall. For grid-connected solar PV power systems, the solar panels should be positioned at the angle of latitude to maximise the amount of energy produced annually. Most Australian homes have a roof pitch of 20° to 30°. If your roof's slope is not ideal, your accredited designer can create an appropriate mounting frame to correct the orientation and elevation of your panel. Failing this, the designer can advise you on the difference in energy output for different tilt and orientation.

How much sunlight should the panels receive?
The amount of energy in sunlight that a solar PV panel receives over a day is expressed in peak sun hours. As the amount of energy generated by a panel is directly proportional to the amount of energy it receives from sunlight, it is important to install panels so they receive maximum sunlight. Your accredited designer will calculate the amount of energy generated by the solar PV panel from the peak sun hours available. Peak sun hours vary throughout the year. Shading / Dirt Solar PV panels should ideally be in full sun from at least 9am to 3pm. They should not be placed in shaded areas and be kept free from dust and dirt. Even a small amount of shade - from things like trees, roof ventilators or antennas - will have a large impact on the output of a panel, as it changes the flow of electricity through the panel. Shading or dirt on just one of the cells in a solar panel results in a loss of power from many cells, not just the one that is shaded. Temperature The amount of electricity a solar PV panel can generate is reduced as temperatures increase. Solar panels operate best at ambient temperatures up to 25°C. However, if the ambient temperature is higher, the panel's output declines.

Do I need batteries for my Grid Connect system?
No, excess solar energy generated on your roof is automatically fed back into the electricity mains via your inverter. Your solar system also automatically sources electricity from the grid when you are not generating sufficient electricity from your solar panels.

What happens at night?
Solar photovoltaic panels require sunlight to produce solar electricity, no solar system will produce electricity during the night. With a Solar Grid Connect system, your local utility will continue to supply your electricity at night.

What happens on cloudy days?
Since solar photovoltaic (PV) technology requires sunlight to produce electricity, the bulk of your solar electricity production will take place in bright sunny conditions. The amount of solar electricity produced by your panels is directly proportional to the amount of sunlight available at any given moment. Solar systems can still generate around 50% of their peak output under bright overcast conditions but heavy clouds which significantly reduce brightness during the day will further reduce performance.

What will happen during a blackout?
By law, any solar electricity system without generator backup must shut down until utility power returns in order to assure a safe working environment for utility line workers. Therefore, your solar systems will switch off until mains electricity is restored.

Why do I still need electricity from the mains?
You still need electricity from the mains because your solar panels may not produce enough electricity to supply your household's needs every day. This obviously depends on the size of solar system you choose and your consumption of electricity. In addition, even if your solar system can generate enough power for you during the day, because the system only generates power when the sun is shining, you will need mains supply electricity whenever there is insufficient sunlight. For example for supply of electricity at night.

Are my solar panels resistant to hail?
Yes. All solar photovoltaic panels have been extensively tested and will withstand a 25mm hailstone at terminal velocity. They are very resistant to storm damage. The tiles on your roof are more likely to be at risk of damage before the solar panels.

Are my solar panels covered under my home and contents insurance?
Yes. Solar Junction recommend that you contact your insurance provider and get the solar photovoltaic system added to your policy.

Will a Solar photovoltaic System cover all my electricity needs?
Depending on your energy consumption and the size of the solar system you decide to put on your roof. In most cases, a solar system can be appropriately sized to meet all of your electricity needs, but it isn't necessary for a solar system to cover all of your needs in order to be cost-effective. Our Solar Consultant will assist you in deciding what size solar system is best for your home.

How much electricity will a Solar energy system produce?
The amount of solar electricity generated obviously depends on the number of panels on your roof, weather conditions and any shading or dust which may settle on your solar panels (before being washed off by rain). These factors can all reduce performance of the solar panels. Our solar consultant will go through these factors with you to assist you to understand.

Can I add more solar panels to my Grid Connect system later?
Yes. Most Solar Power Grid Connect systems can be upgraded with additional solar panels installed depending on which solar system size you choose and the capacity of the inverter. If you wish to increase your solar system significantly at a later date it is better to install a larger inverter now. Your solar consultant will discuss the options with you so you can make an informed decision.