What's the difference between on-grid and off-grid solar power systems?
Most solar power systems in Australia are on-grid, which means they're connected back to the main energy grid. This means you can power your home all year round, even if your solar panels don't produce enough electricity.
If you can't connect to the grid, or if you only want to use the power generated by your solar system, you may be able to go off-grid. Then, you would only have access to energy generated by your solar system and, if it ran out, so would your power.
How does an on-grid solar power system work?
On-grid solar power systems are hooked up to the main power grid and linked to your existing energy supplier. This is the umbrella term for any system hooked up to the grid, including grid-tied, grid-connect and grid-direct systems.
As on-grid solar systems are connected to the main power supply for your area, they don't need to produce all the energy you need. And if your system produces more energy than you use, it sends the surplus back to the grid, which means you can get paid for producing electricity. You can even have a net metering agreement with your electricity supplier, through which you stand to receive compensation for the excess electricity you provide to the grid.
What do I need for an on-grid solar power system?
The requirements for this type of solar power system typically include:
- Solar PV (photovoltaic) panels
- An inverter
- Electrical safety gear like breakers, fuses and disconnects
- A system to monitor production and transfer of energy
- Professional installers
Note that when you get an on-grid solar power system, you may still experience power outages when there's a failure at the grid. This is because all on-grid systems are powered down during repair periods to reduce the risk of electrocution.
How does an off-grid solar power system work?
The use of off-grid solar systems is more common in regional and rural parts of Australia, where people cannot connect to the grid at all. When you're off the grid, you'll need to have enough PV panels and battery storage to power your home all year round. Battery storage is particularly important during the evenings and winter months, when solar panels generate little to no new electricity.
With an off-grid system, you also have to regularly check your energy usage and storage to make sure you keep your output below maximum levels. Otherwise, you could overload the system.
What do I need for an off-grid solar power system?
The typical requirements for off-grid solar include:
- PV panels
- A solar battery system
- A charge controller to keep the battery from overcharging
- Electrical safety gear, such as breakers, fuses and disconnects
- A system to monitor and balance consumption of energy with production
- Professional installers
Hybrid solar power systems
You also have the option of upgrading an on-grid system by incorporating the use of battery backup. Power from the solar power system and the grid works in charging the battery backup, and if you suffer from a power outage you can turn to the backup. Switching to the backup in such a scenario can be manual or automatic, depending on the kind of system you choose.
The components that go into making a hybrid system are essentially the same as ones you’ll find in an on-grid system, with the addition of suitable battery backup.
Should I choose an on-grid or off-grid solar power system?
Choosing between an on-grid and an off-grid system essentially boils down to whether or not you have access to the grid. If you don’t have access to the grid, you have no other option than to go off-grid.
If you have access to electricity from the grid, installing an on-grid system makes more financial sense. This is because on-grid net-metered systems offer high levels of efficiency and almost unlimited storage through the grid. If you generate more energy than you use, you can also get payment in the form of feed-in tariffs (FiTs).