Key solar questions for beginners
The size of your solar PV system will depend on:
* The physical un-shaded area you have available for the installation of your panels check our roof space calculator on this site;
* How much you are prepared to spend ($5,000 to $10,000 will get you a decent size solar system)- if it is very cheap, the quality is very unlikely to be great, whatever the sales person says;
* What portion of your electrical consumption you wish to generate or offset.
To work out what size solar PV system you require, you need to analyze your household’s daily electricity consumption. Your electricity bill shows your household’s electricity consumption in kilowatt hours and your average daily electricity consumption. From this you can calculate the average amount of electricity your new solar PV system needs to produce to cover your electricity needs. Naturally the solar system needs to produce the electricity when you are likely to consume it. If you are out during the day and only run energy intensive appliances at night, then maybe solar is not for you – unless perhaps you also install a storage solution. If on the other hand you are at home with the children and grandparents during the day, then a solar system can certainly make sense. Our LG solar dealer can assist you in working out how much benefit a solar system will give to your particular situation.
Clean panels mean that your solar power system will perform at the optimum capacity. A dirty or leaf covered panel will drop the efficiency and generating power of the solar power system.
It is estimated that a dirty panel looses around 5% efficiency compared with a clean solar panel. So if you are in a very dusty or high traffic location do consider to have your panels cleaned every few years. On the otherhand if your area receives regular flushing rain, then extra cleaning might not be required.
LG never recommends for end customers to climb on the roof to clean their solar panels. Get a qualified tradesman to do it for you. Overall remember your LG panels are self-cleaning in the rain due to the type of glass used on the solar panel and our panels will require low maintenance.
Maybe consider at time of purchase to negotiate one or more follow up visits by the installation company in years to come for check up, maintenance and cleaning. Make these follow up visits a condition of your buying decision and negotiate a fair price for the follow up visits.
A few things to keep in mind when you get the panels cleaned.
- The goal is to get the glass clean and clear as possible so you don't want to scratch it with abrasive soap or abresive cleaning sponge.
- A soft cloth/sponge and some soft small amount of biodegradable soap can be used. If the panels get cleaned frequently then one might just get away with washing them straight with water.
- When the tradesman gets on the roof to clean panels advice them to be very careful as it will be slippery once one starts washing panels.
- For 2nd storey we always recommend scaffold/harness and all other relevant safety equipment;
- Do not have solar panels washed on very hot days as cold water and hot panels do not mix. The glass on the panel, while toughened and strong could be damaged by sudden shock in temperatures.
- Do not use high pressure washing equipment on solar panels. The high pressure could force water into junction boxes OR PLUGS which are not 100 sealed or via other areas. Hose is acceptable if pressure is not on full and if you avoid cable connections and junctionboxes.
- I have seen installers use a soft pressure level on a hose and a soft broom to clean panels . this seemed effective.
- ALWAYS MAKE SAFETY YOUR AND YOUR TRADESMEN'S PRIORITY - WATCH FOR SLIPS DANGER AND LIFE ELECTRICITY CABLES.
You need to be a certified installer before you install a system and be eligible for government rebates. The designer and installer of your solar PV system must be accredited by the Clean Energy Council.
Most of the modern solar power systems have a number of safety systems built-in in. The installation procedure, while varying slightly from State to State requires that there are cut off switches and circuit breakers on the roof next to the panel, next to the inverter and in the meter board.
The inverters also have safety features built into it to monitor the correct functioning of the system, and will switch off, when certain safety parameters such as system voltage have been breached.
When your solar system is not receiving direct sunlight eg at dawn or dusk it will typically not generate enough power to supply your household needs. At these times your power supply will automatically come directly from the electricity grid. Without sunlight the solar system can not switch on. On cloudy days, some output is available with none at night.
In Australia the back-to-grid or grid connected solar power systems as they are called are common because of the regular electricity supply and the extensive network developed over the years.
The availability of regular and reliable electricity via the grid has made grid connected system popular. The most common use for solar electricity today is called an On Grid Solar System.
On Grid means the solar electricity system is connected to an existing grid power supply. This use for solar electricity is popular because instead of using batteries for storage, electricity is imported and exported to the grid as generation and demand varies. This helps reduce the cost and complexity of home solar systems as battery components are eliminated.
On Grid solar systems use inverters to convert the electricity produced by solar panels to the same voltage and frequency as grid power and to synchronize the systems together. On Grid solar systems incorporate safety devices which allow solar systems to be isolated automatically if the grid is shut down for safety or maintenance purposes.
On Grid systems constantly monitor the voltage and frequency of the grid and specific standards exist to ensure that solar systems comply with this in Australia and other countries. This is one reason why choosing a high quality inverter is important. Lower quality inverters can suffer “trip-outs” if the grid power is varying and but higher quality units are better able to cope with fluctuations and keep your solar power system connected.
They are two different technologies used for different applications - one for generating hot water (Two panels in foreground) and one for generating renewable electricity ( Six panels in background). Both technologies use collectors - also known as solar modules or solar panels - usually installed on the roof. The source of the energy for both technologies is same - the sun, but the technology is completely different.
Typically solar array cabling is terminated into a roof mounted junction box fitted with an isolator which allows the solar array to be disconnected at the roof. These housings are typically plastic and should be very high quality as they can degrade quickly and cause problems or danger if they fail, have water enter them or are of a cheap made.
Particular attention should be paid to the location and quality of water proofing of this box, which is a common failure mode in low quality systems.
From the junction box, it is common for one of two pairs of cable to be routed in conduits to the central inverter which is usually mounted near your switchboard. Particular attention should be paid to the way these cables have been installed and terminate at the circuit breakers. All these elements provide electrical protection to you and your system.
Please see our Checklists section for what to look for in a quote before you buy a system.
An important feature in the construction of solar panels is the junction box. Attached to the rear of the solar panel, it serves several important functions.
Firstly, it seals the rear of the solar panel where the interconnectors exit. As such, it is vital that the junction box is well sealed so that moisture cannot enter the panel. Some are permanently sealed, like LG's junction box which are rated IP67, which means that it is completely sealed.
Secondly, the junction box it houses connection points for the cables which exit to allow you to connect each solar panel together. These connections need to handle different types of weather conditions over the years and need to handle quite high currents so quality connections are very important. The solar panel junction box also houses small electronic devices called diodes which protect the solar cells in the case some are partially shaded. Some diodes exhibit higher losses and create higher temperatures than others, leading to potential stress for the solar cells.
Lastly, many solar panel junction boxes are filled or partially filled with a sealant to protect the entry of moisture to the solar panel and are sometimes filled to the brim to fully encapsulate the diodes, connections and cables. The quality of this sealant is an important factor too.
When you are assessing a solar panel, look very closely and observe the type and integrity of the junction box to ensure it fits well, is perfectly sealed and if operable, that it seals up perfectly when re-closed. In the case of LG’s solar panel junction box, they are permanently sealed to prevent moisture entering the panels(IP67 rated).
Most systems will get inspected by the local energy company in due course. Some inspections are carried out by government nominated agencies in form of an audit. If you as a consumer want to get a private inspection done of your system, you can contact the Clean Energy Council or any certified installer to do so. There might be a cost associated with the privately requested inspection.
The Clean Energy Council, the Department of Climate Change and Energy Efficiency and the Office of the Renewable Energy Regulator also conduct its own inspection program. This applies to installations completed by accredited designers and installers. It occurs on a random basis and aims to ensure that solar PV systems meet the Australian Standards and Accreditation Guidelines.
It is very important to get the solar quote person come to your house and investigate your particular circumstances. It is not enough to get a final quote over the internet without the company actually having seen your house. Would you accept a quote to install a new stairway or a new bathroom in your house via a call centre - without a site visit? If the quoting company can not give you a free site inspection, then you are not their priority - not now and not when they install your system. For some in the solar industry that follow the internet and google map sales model, it is all about sales volume - not necessarily about solar sales service.
Let me give you an example:
What is the electricity consumption pattern of my household and how does this affect the installation direction of my panels? Let me explain:
In example A, if you are a nurse and work shift work from 5am and come home by 2.30pm, it would make no sense to install your solar system on an easterly or north-easterly roof, as your solar system will perform at its peak early in the morning till lunch time - just when you are out. Therefore your system generation would mostly be exported and nowadays electricity retailers only pay relatively low feed-in tariffs. Therefore your financial advantage from you solar system would be severely reduced. IT IS IMPORTANT that you install the solar system on a roof direction which matches with your electricity consumption pattern. In the case of example A it would be much better to have the solar system installed on a north-westerly or even a westerly roof. That way the solar system output would be at its max in the hours from 1pm to late afternoon, a much better match with your likely consumption pattern. As you need to have the electricity you use offset as much as possible by the"free" solar electricity your consumption pattern and the peak generation period of your system should match. Let your LG authorized installer explain this fact a bit more.
Some cheap solar system sales companies are only focused on the sale and not the after service or installation details. They use cheaper materials, but via smart marketing make the customer feel they buy top of the range quality. Many solar panels with European sounding names are actually made in China. Make sure you get in writing, from your installer where your inverter and panels are made and double check these facts on the internet. In the past 5 years over 20 major solar manufacturers have left the industry, and in many cases customers were left stranded with long term warranties, which are now worthless.
If you received a rebate when buying your solar power system, then the solar rebate conditions usually require that the solar system must remain at the installed location. This means you cannot simply unscrew the solar panels and mounting system, disconnect the solar inverter and take the whole system with you. The panels have to remain with your old home.
The Warranties provided in the LG Manufacturer’s warranty are transferable when the module remains installed in its original location. This means, when a customer sells their home with LG Modules installed, the new owners of the property will continue to enjoy the LG manufacturer’s warranty protection. The warranty period runs from the original date of purchase.
kW stands for kilowatt, or 1,000 watts. It is a measure of power. Your LG solar power system is rated according to the number of watts it can produce each hour. This solar panel rating is seldom fully achieved in real life conditions, as dust particles and clouds constantly affect light quality. For example 12 x 260Watt panels will make up a 3.12 kW system. Normally you would then also use a 3 kW inverter with this system to convert the panel’s direct current (DC) voltage to mains supply voltage.
Usually your electricity bill is billed in units of kW/h. kW/h stands for kilowatt hour. It is a measure of energy. If you use a 1 kW electric pool pump for one hour, it will consume 1 kW/h of electricity. Or if you use 20 x 50W down lights for an hour they will consume 1kW/h of electricity. On a sunny day the solar system described above (3.12 kW) will produce approximately 2.5 to 2.8 kW/h per hour. Only on very sunny and clear days eg. after rain, your 3.12kW solar system will produce 3.12kW per hour.
To be eligible for government rebates, the designer and installer of your solar PV system must be accredited by the Clean Energy Council. The Clean Energy Council’s accreditation scheme ensures that accredited designers and installers of solar PV power systems:
- have undergone the necessary professional training
- follow industry best practice
- adhere to Australian Standards
- routinely update their skills and product knowledge.
An accredited designer/installer will provide you with a solar PV system design and specification. This will include things such as:
- establishing your electrical loads over an average day using a load analysis
- recommend the size of your solar PV system
- recommend the type and size of inverter/micro-inverter
- establishing the location of solar panels in relation to angles, available sunlight, your consumption pattern, shading and temperature.
You have the right to ask the installer to show you his licence during the install process.