Solar 2020: FAQs

FAQs

FAQs

Below are the most frequently asked questions (FAQs) that we get asked.

If you’ve got a question for us that isn’t listed below, please don’t hesitate to contact us.

Solar 2020 FAQs

What is Solar Energy?

Solar energy is the sunlight energy that is given off by our Sun that strikes the surface of the Earth. The Sun is approximately 150 million kilometres from the Earth. At the top of the atmosphere the Sun’s energy is about 1.3 kW per square metre and after passing through the atmosphere, this energy intensity is reduced by dust and water vapour as well as absorption to around a maximum of 1 kW per square metre. The final maximum energy level is used directly by solar modules to produce DC energy and by wind turbines by the winds that the heating and cooling of the Earth that this energy causes.

What is a solar module?

A solar module is a device made up of solar cells which convert the energy from the Sun via the Photovoltaic (PV) effect, into direct current (DC) electricity, which in turn can be used directly to run or charge DC appliances or via an inverter to directly connect to the alternating current (AC) utility grid network that provides power to homes and industry.

Are there different types of solar modules?

Yes there are different technologies used in solar modules to capture and utilise the Sun’s energy. Most manufacturers today use either mono (single) or poly (many) crystalline cells to make their solar modules. These cells are very thin and can be from 200 to 300 micron in thickness. A typical high efficiency solar module will have at least 36 solar cells and as many as 72 or more cells connected in series, terminating into a junction box on the back of the module. Other technologies used include those in the thin film family of solar modules. Some examples include amorphous silicon, copper indium diselenide (CIS), cadmium telluride (CdTe) and gallium arsenide (GaAs) thin films. All these technologies use very small amounts of material, are easier to manufacture on inexpensive substrates and are easier to manufacture in mass production techniques. Typically though, thin film technology solar modules are not as efficient in converting the sunlight into electrical energy, but advances are being made to increase the efficiencies.

How does the electricity get generated from a solar module?

In simple terms, when the energy from the sunlight hits the surface of a solar module, free electrons in the solar cell material are knocked free and collected by the external electrical circuit outside the cell material. Sunlight is made up of different light wavelengths/energy levels and for a mono or poly crystalline silicon cell, the blue part of the spectrum causes this photovoltaic effect. Other thin film solar modules can be constructed in such a way that more of the light spectrum energy is used thus increasing responsiveness and efficiency.

How long do solar modules last?

All solar modules are solid state devices and as such have no moving parts. All the cell material and internal connection ribbons between the cells are laminated between a sheet of low iron glass and a weather proof back sheet, which keeps all water, dust and other impurities out of the cell circuit. The output cables are terminated in a weather proof electrical junction box. All this manufacturing technique enables most manufacturers to warrant their products for 25 years, so an expected life of at least 30 years or more would not be unreasonable to expect.

How many solar modules do I need?

This really depends on the type of system you need. For a residential grid-connect system, most systems start off at 1kW and there are different solar module wattages available to choose from. Typically your consultant will recommend the best size to do that job. For a system this size for example, you could have 6 solar modules, each rated at 170W for example. They would be all connected in series before the output cables are run down to the inverter.

What does the inverter do?

Put simply, the inverter takes the high voltage DC power from the solar modules and inverts the power into AC power that can be fed directly back into the grid network. A good inverter will have a high efficiency in doing this inversion so that precious solar power is not wasted. Along with the inverter will be supplied DC and AC disconnect devices so that the power from the solar modules and the power coming out of the inverter can be safely isolated. Installation of the solar modules and inverter must be carried out by an experienced and licensed person due to the dangerous high DC and AC voltages present.

What happens if the grid fails like in a blackout? Do the solar modules still work?

No, the inverter will stop sending power to the grid to safeguard the workers who will be working on the power lines to get the main grid working again. This is a standard and required feature of all inverters. This action does not harm the solar modules. When the inverter senses that the grid has been restored, it will automatically reconnect the solar power to the grid.

Can I have batteries in the system to keep just my house powered if the grid fails?

Yes there are systems where this is possible and it is desirable in those countries where the power is failing many times per day. However, these systems are more expensive and for the vast majority of customers around the world, systems without batteries are the standard.

Can I monitor the performance of my system?

Yes. All quality inverters have options to either view the performance of your system and/or to log the performance data for viewing on your computer. Typically these options are at additional cost.

What maintenance do I need to do?

Being a solar power system, there is very little the owner needs to do. Everything works automatically and what minimal maintenance that is required is listed in the manual that is supplied with your system. Some of these items may need an electrical tradesman, but in general the system is maintenance free.

Will I get paid for the electricity that I export to the grid?

Generally speaking, yes you will, but it will vary depending where you live. Some state governments will offer a net metering purchase where only that amount of solar electricity that is not used within the home and is exported, will be credited to your account. Other authorities are more sensible and generous and will pay the gross amount of power that is produced by your system, whether it is consumed in the home or not. This makes the payback period for the balance of system cost of your system very much quicker.

Residential Enquiries

CALL 0419 305 771

Commercial Enquiries

CALL 0422 975 591

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