SOLAR PV - HOW DOES IT WORK?
Solar Photovoltaic (PV) panels generate clean electricity by converting sunlight into electricity.
They are fitted on the roof of a building in a northerly direction. Depending on the roof pitch, the panels will be fitted on a raised frame or mounted parallel to the current roof pitch to maximise the amount of sunlight hitting the panels.
This conversion takes place within modules of specially fabricated materials that make up the solar panels, and the energy thus converted is what is known as clean electricity.
In most cases, a device known as an inverter is used to connect the solar panels to the mains power supply.
HOW DOES A GRID-CONNECTED SOLAR PV SYSTEM WORK?
Most suburban homes in Australia run on AC power as a result of being connected to the electricity grid.
This means an inverter is needed to transform the DC (direct current) which is generated by solar panels into the AC (alternating current).
Once connected to a solar PV system, houses with solar systems use solar power first before sourcing electricity from the grid.
At night when the panels are not producing electricity the power is then drawn from the electricity grid.
Only systems which have a battery backup (optional) store electricity in the batteries which can be used at night or during blackouts.
HOW MUCH POWER DO THESE SYSTEMS GENERATE?
Generally, the greater the capacity of the solar PV system, the more power it generates. Sizes range from 1 kilowatt (kW) or 1.5 kilowatts, increasing to 5 kilowatts (contract limit with Synergy).
Many factors dictate the performance of a solar power system. Sunday Energy representatives will be able to calculate the power generated during a site assessment.
As a general rule of thumb for Perth, each kW of solar on a north facing roof at a 20 degree roof angle should generate an annual average of 4.5 kWh (units) per day.
Another factor to take into account is that solar panels produce more energy in summer than they do in winter.
WHAT IS THE COST OF SOLAR PANELS?
This will very much depend on your requirements and whether you want to completely offset your household's electricity use for the next 25 years, or whether you simply want to partially offset your energy consumption for the next 5 – 10 years before requiring a system upgrade.
The more informed you are as a consumer, the more value you are likely to obtain from your system which will have been purchased with your needs in mind.
This should be done in close consultation with your qualified solar PV consultant who must be a qualified industry professional.
Sunday Energy's accredited designers have the expertise to provide you with the right kind of guidance to make the right decision for your needs.
There are other variables, such as:
- Height and type of roof
- Site preparation (i.e. condition of roof or ground)
- Government rebates and support schemes (vary from state to state)
- Type and quality of panels and inverter
- Contractor installation costs
- Commercial systems may require additional services such as structural engineering etc.
All of the variables would be identified during the site assessment.
All site assessments by Sunday Energy's accredited designer are free of charge with no obligation to enter into a contract.
The actual price can only be determined when a site assessment takes place.
Following a full and comprehensive consultation with the client, Sunday Energy's accredited solar energy designer will provide a written quote taking all the variables into account.
WHAT IS THE IMPORTANCE OF AUSTRALIAN STANDARDS?
Only buy solar panels and inverter models that meet Australian Standards. Solar PV systems must also comply with The CEC Design and Installation Guidelines.
This ensures that the solar PV equipment has been tested in Australian conditions and are suitable.
Often the equipment is made in countries and tested under completely different environments to Australia's which has other considerations such as dust, cyclones or extreme fluctuations in temperate that may not be relevant in the other countries.
Sunday Energy only supplies panels and inverters which meet these standards. We also continue to monitor the performance of our systems over long periods to ensure reliability and quality control.
WHAT DOES THE IP RATING MEAN?
The IP rating or the Ingress Protection Rating represents the protection provided in electrical enclosures against the access of objects, dust, accidental contact, and water.
The code usually has the letters IP followed by two digits. These ratings provide consumers with a more detailed description of what their electrical product is protected against.
The first digit specifies the protection of the enclosure against access to hazardous parts (electrical components, moving parts and foreign objects.
The second digit - protection of the equipment inside the enclosure against water.
Sunday Energy only use inverters with an IP rating of 65. (6 refers to “dust tight” – no ingress of dust; complete protection against contact.
The second digit 5 “water jets” – Water projected by a nozzle against the enclosure from any direction shall have no harmful effects.
WHAT ABOUT WARRANTIES AND GUARANTEES?
Solar PV panels generally come with a performance warranty of 25 years.
An Inverter warranty should be at least five years. Inverter performance is dictated by its positioning.
A poorly considered inverter position will reduce the life of the inverter and effect daily energy generation levels. Your Sunday Energy representative will advise of optimum positioning of the inverter.
Workmanship guarantees generally span 5 years.
We provide you with an installation manual that provides operation, maintenance and safety information. This also includes system performance.
A written confirmation of statements made by our designers includes performance claims, guarantees and warranties.
WHAT ARE THE AVAILABLE GOVERNMENT SCHEMES WHICH WILL LOWER THE COST OF PURCHASING A SOLAR PV SYSTEM?
There are currently two types of financial assistance in place for solar PV systems in Australia.
Renewable Energy Certificates (AKA) Small Scale Technology Certificates. The Renewable Energy (Electricity) Act 2000 (also known as the RET scheme) has created an electronic form of currency known as Renewable Energy Certificates (RECs). The price of these certificates change according to market conditions. You may assign your RECs when you purchase your solar PV system to a registered agent for up front discount on your solar PV panel system (most consumers take this option); Your designer/installer must be accredited by the Clean Energy Council in order for you to claim RECs for the full 15 year deeming period upfront (which is the most commonly chosen option by Sunday Energy clients). The size of the solar PV system and the price of RECs at the time the system is installed will determine the level of subsidy available.
WHAT ARE THE DESIGN AND SPECIFICATION REQUIREMENTS FOR A SOLAR PV SYSTEM?
Only Solar PV systems installed by a Clean Energy Council accredited designer / installer are eligible for government rebates.
Your Sunday Energy designer / installer is fully accredited and registered with the Clean Energy Council.
You can rest assured that your Sunday Energy designer / installer has the training and expertise to provide you with the best possible advice and service.
HOW DO I DETERMINE THE SIZE OF MY SOLAR PV SYSTEM?
There are several factors to consider when determining the correct size of your solar PV system, such as:
- The amount of full sun area available for the installation of solar panels
- Your budget – how much you are prepared to spend
- The proportion of your electricity consumption which you wish to generate
You will also need to analyse your household’s daily electricity consumption; your regular electricity bill which measures your household’s electricity consumption in units and can provide some of the necessary information, enabling you to calculate your average daily consumption.
With the assistance of your accredited designer / installer, this will help you determine the average amount of electricity your solar PV system needs to produce to offset or cover your electricity needs, based on your budget and investment.
WHAT TYPE OF PANELS ARE AVAILABLE AND WHICH SORT TO BUY?
There are four main types of solar panels available – each have their own benefits.
Your Sunday Energy accredited designer / installer will help you to choose the best type for your needs when the site assessment is carried out.
Features of suitable panels are:
- Mono Crystalline (Monocrystalline c-Si) These panels are a proven technology that has been in use for over 50 years.
- 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.
- Thin Film or AmorphousThese 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 or Amorphous panels and to refine the manufacturing process. The most common varieties of Thin Film or Amorphous panels are:
- Cadmium Telluride Thin-Film panels (CdTe)
- Copper Indium Gallium Selenide Thin-Film panels (CIGS)
- Amorphous silicon Thin-Film panels(a-Si)
WHAT IS THE CORRECT ANGLE FOR SOLAR PV PANELS?
Solar PV panels work best when pointed directly at the sun. In Australia, this means they should be facing north for optimum electricity production.
Roof slope is important and if not ideal, your Sunday Energy accredited designer / installer can create an appropriate support such as a mounting frame for optimum tilt. A minimum tilt of 10 degrees is recommended so that self cleaning by rainfall can occur.
WHAT ABOUT EXPOSURE TO SUN, DUST AND DIRT?
Solar PV panels function best when in full sun from at least 8am to 4pm and should be kept free from dust and dirt.
Sunday Energy conduct shading assessments and your Sunday energy accredited designer will be able to calculate all shading and outputs for optimum placement of your system on site.
DOES TEMPERATURE AFFECT MY SYSTEM'S PERFORMANCE?
Your Sunday Energy accredited designer will assess the roof structure when conducting the site assessment and consider maximising air flow.
Sunday Energy framing system allows for maximum airflow across the panels (as well as levelling of uneven roof surfaces).
This is important because the amount of electricity a solar PV panel can generate is reduced as temperatures increase.
Solar panels operate best at ambient temperatures up to 35°C.
WHAT DOES AN INVERTER DO?
An inverter converts low voltage DC electricity into AC electricity.
Solar PV panels produce low voltage DC electricity. The inverter converts this into the AC electricity needed to supply power for standard appliances.
The efficiency of an inverter is measured by how well it converts the DC electricity into AC electricity. This usually ranges from 95% to 97.5% for most models. Sunday Energy only use and recommend inverters with the IP 65 rating.
Sunday Energy inverters comply with Australian Standards. This is required to be eligible for the REC’s and Solar Credits.
IS MY EXISTING HOME METER SUITABLE FOR SOLAR POWER?
Once you have notified Synergy of the installation of your solar power system, Synergy may request / organise the installation of a bi-direction meter as part of the 7cent Renewable Energy Buy Back Scheme. Synergy will charge for the change over of the bi-directional meter. Pricing is between $176 single phase and $300 dollars three phase.