FAQ
What is a kilowatt?
Kilowatts (KW) are a measure of instantaneous power. Every load requires a certain amount of power to run. 1 KW = 1000 Watts
What is a kilowatt hour?
Kilowatt hours (kWh) are a quantity of energy. It is the amount of energy equal to one kilowatt of power over one hour of time.
What is a load?
In electrical terms, a load is anything that consumes electricity. Typical loads within a house include lights, appliances etc although the entire house can be considered as a ‘load’ on the grid.
What is PV?
Photovoltaic’s (PV) is a technology that uses a semiconductor to convert the light directly into electricity.
What happens at night or when there is no sun?
Grid connected PV systems are connected to the electricity grid. During the day, any power that the system produces in excess of what is used is fed out through the meter into the grid, turning the meter backwards and clocking up a credit.
When more electricity is required than that being provided by the PV system such as during the night or low levels of sun, electricity is drawn in from the grid as per usual. This is an automatic process and happens with no action required by the user.
What happens during a blackout?
Grid connected systems are required to shut down or disconnect from the grid in the case of a blackout. This is to avoid electrocution to electrical workers who would otherwise receive power into the lines from the PV system. In order to maintain power during a blackout, a battery backup system is required. This adds a standalone inverter which is capable of running independently of the grid.
What’s the right size system for me?
This will vary depending on how much electricity is required. Grid connect systems are flexible in that they allow for any portion of the houses power requirements to be covered by solar with the rest covered by the grid.
How much power will the system produce?
This depends on the size (measured in watts) of the system and the amount of sunlight that reaches the modules.
In simplified Electrical terms the power output (measured in watts) of a photovoltaic generator is a function of the open circuit Voltage (ocV) multiplied by the short circuit Current (scI) less any efficiency losses in the system. For sizing purposes this instantaneous value is usually multiplied by the averaged yearly peak sun hours (PSH) available at the site during the day.
For example a system rated at 1050W (1.05kW) facing North with a tilt angle of between 15 and 30 degrees (most roof pitches fall within this range) located in Perth will have a yearly* average of 4-5 peak sun hours exposure daily. *(more on summer days, less on winter days)
The systems averaged daily output would therefore be around 1050W × 4hrs = 4200Watt hours (4.2kWhrs). This is the same as 4.2Units of electrical energy as shown on your electricity bill; Units are a measure of energy use in watts per hour.
It is the job of the competent installer to ensure that system losses are minimised.
MESA carries out its own product claims verification appraisal, especially with regard to PV manufacturer’s specifications claims, before recommending a product to its customers.
How will the modules be mounted and do they need to face north?
The modules will be mounted on the roof using an Australian Standards approved methodology best suited to the building construction.
An aluminium frame is fixed onto the main roof beams using stainless steel fixings. The Panels are clamped to this frame.
It’s ideal for solar modules to be facing north however they can also face east or west with only a small loss in output.
How much space does the system need?
This will depend on how many and what type of solar modules you wish to install. MESA’s standard recommended system utilizes monoxtal panels where each kW of PV panels requires approximately 8sqm.
Can solar panels work in the shade?
The power output of all Solar panels regardless of technology is severely compromised by shading issues.
Shading should be avoided where ever possible.
How long with the system last?
The system equipment and installation must comply with strict Australian Standards regulation. These standards expect that the RE generator will produce its as new specified output for at least 15 years. In practice many systems which where installed in the 80’s are still working and generating 90-100% of the original spec. Since that time not only have manufacturing techniques improved but also the knowledge base and quality of work of the installing tradespeople. It is not un realistic to expect that a competently installed PV generator using approved components located in a relatively stable environment will still be generating near its peak output after 20 years.
Are the solar panels fragile and will they be damaged in a hail storm?
All approved solar panels must pass minimum tests which include a hail damage test using a steel ball one inch in diameter.
What about maintenance?
No regular maintenance is necessary. Cleaning bird droppings etc from the panels will help maintain peak power levels but is only recommended for easily accessible systems. Generally the slope of the panels is enough for rain to clean sufficiently.
How much greenhouse gas emissions are reduced by using solar energy?
A typical 1kW system will save approximately 1400kg of CO2 emissions annually.
How much?
Several factors affect the pricing of the GC PV system, these are
The size of the system and where it is to be installed; Relative currency values, World market product availability; the fluctuating RECs market.
At this time however for a typical 1kW system our price including installation and GST is around: $9000.00au, before RECs exchange discount.
This total cost is discounted in exchange for the RECs available for the system once installed
At this time RECs are worth around $30-34 each; a 1KW system will create around 103 RECS achieving a discount of $3000.00.
Total cost for the installed system: $9000 – $3000 = $6000.00
