You may be surprised to know that solar panels work in relation to the number of power phases coming into a house or a business. This is crucial to decide the kind and size of inverter you must attach to your solar panels. Most of the homes connected to the grid in Australia use a single phase. Three-phase power supply transmits more power than a single phase.
Three-phase is useful to handle bigger loads. The basic distinction between the single-phase and three-phase power supply is that the single-phase requires two wires for completing the circuit, i.e., the conductor and the neutral. The conductor carries the current and the neutral is the return path of the current.
The single-phase supplies the voltage up to 230 volts. Three-phase electrical systems on the other hand have three live wires coming in and one neutral wire going out. A three-phase system supplies three alternating currents.
The peak of each phase is separated from that of the others by only one-third at any given time, allowing for a near-continuous flow of power throughout the circuit. In Australia, three-phase power lines run at 400 Volts and 50 Hertz.
As we stated earlier, your phase affects your choice of solar inverter. You should install a single-phase inverter if you have a single-phase electric power supply you can install both single and three-phase compatible inverters if you have a three-phase power supply.
However, technicians recommend you’ll either have to install three single-phase inverters for each phase, or one three-phase inverter that will work across all three phases. A single-phase inverter usually comes in a capacity of less than 5kW. But if you are looking for an inverter larger than 5kW, and you have 3-phase power in your home then a 3-phase solar inverter is ideal.
How to find out whether single-phase or three-phase electric supply
You can find out if your house or business has single-phase power or three-phase power by checking your meter box. A meter box controls the flow of power to your property and is typically a single large panel(s) that contains various switches, circuit breakers, and other power control equipment. The next step is to find out the circuit breakers.
A circuit breaker is an electrical switch designed to protect an electrical circuit from damage caused by overcurrent/overload or a short circuit. Its basic function is to interrupt current flow after protective relays detect a fault.
There will be a circuit break labeled as the “Main Switch” and from this; you will determine which phase of power you have based on its width. Single-phase power meter boxes only contain one fuse cartridge, and three-phase power meter boxes on the other hand consist of three fuse cartridges
Advantages of a three-phase solar system instead of single-phase
Single-phase electric supply can carry up to a 5kW inverter. The three-phase inverters come in a capacity of up to 30kW which allows users to install a high-capacity solar system.
3-phase solar inverters manage voltage rise and reduce the chance of appliance failures due to high voltages as the voltage rise in a single-phase connection is higher than that of 3-phase power.
By using the three-phase connection, the power supplied to the grid is distributed evenly and leads to grid stability.
It increases the local grid voltage and your circuits will have less chance of short-circuiting due to high voltage issues.
If a 3-phase inverter is chosen, the consumers can meet their energy demands easily reducing their dependence on the grid for energy and leading to reduced utility bills.
Three-phase power combined with rooftop solar can reduce your household power bills to next-to-nothing.
It also provides you with scope to add energy-intensive appliances and power them for free with your solar electricity.
Getting a three-phase connection at the build stage is cheaper than doing it later. It also gives you greater scope to power your home 24/7 with solar panels and battery storage – and easily add fast charging for an electric vehicle down the track.