Export limiting keeps the grid safety
If you are looking at solar for your home, one question you may be asked is your home on single-phase or three-phase connected?
Normally, you might hesitate a bit at that time because you maybe never cared about it before your home solar installation.
So, what is it?
Phase is referring to the distribution of load.
Single phase power has just one live wire, while 3 phase power uses three active wires. You will find 1p or 3p out from your meter box. Most homes were built with a single phase connection.
You just open your main meter box (MSB) and take a look, if you see one main switch you have single phase power, and if three switches then you have three phase.
How important sales need to check this point with you before solar installation?
Export limiting depends your solar system size. According to the rule of Distributed Network Service Provider (DNSP), your solar export must be within the specified range and you will get a document regarding detail of restriction values. For example in SA, it is called embedded generation sent to you by SAPN, and it will tell you the export limit rules such as 5kW/phase in the form.
Please note: professional installers will help you set up the export limiting during the installation since not limiting would result in a penalty.
If your system is 6.6kW and your inverter is just 5kW, so the output is exactly 5kW and the limit value is consistent for single phase home. This is because the maximum power of the inverter itself is 5kW.
Single-phase households can usually be equipped with inverters up to 10kW, and solar panels size is up to 13.3kW (That is 1.33 times the size of the inverter) . You won’t see your system generating 10kW all the time if you can’t find a place for that 10kW. Therefore, it needs to be discussed separately.
Case 1:
If your system is solar only, and you do not use electricity during the day, then you will see that the highest power generation curve of your system is always at 5kW. But if you start to use 5kW load, you will see that your power generation peak will become 10kW, which is 5kW for output plus 5kW for use.
Caes 2:
If your system is solar with battery, in other words, you have two 5kW hybrid inverters and 5kWh batteries, and you still use 5kW electricity during the day, then you will see that your power generation is always at 10kW (5kW*2= 10kW with full capacity), but export is 0 until the battery is full. This is because the hybrid inverter will automatically determine the priority, and the power consumption and battery charging are prioritised over the export.
