On September 28th of 2016, a massive storm came across with around 80,000 lighting strikes and at least two tornadoes. The natural disaster damaged many buildings and the electricity grid infrastructure was no exception. It is now known as the South Australia Blackout.
Yes, sometimes the destructive force of nature is indomitable and it can cause drastic damage to our cities and properties.
The wind force damaged around 23 pylons on transmission lines which created a cascade effect that shut down sectors of the grid one by one.
Wind farms and generators reduced their power output, power flows increased on specific transmission lines and eventually, the overload in the grid was so big that the system had to shut down. By 4 pm almost the entire state had been blacked out.
During December, South Australia also experienced other widespread blackouts caused by floods, wind and fallen trees. Many people still had no electricity up to 46 hours later.
Blackouts can occur during storms, tornadoes, floods and other natural disasters and no one knows when the power grid will be restored again – it could take hours or many days. That is why having protection against blackouts is an asset that Aussies are starting to consider more frequently.
Grid-tied solar panels: The solution to blackouts?
You might be thinking of installing solar panels, considering them as the main protection against blackouts.
However, there are some details that you must know in case your main incentive to install them is to protect your home against blackouts.
There are mainly two types of solar systems.
The first and most popular is the grid-tied system. It is composed of solar panels, combiner boxes, energy meter and an inverter to convert DC power into AC.
The grid-tied version is a PV array system that generates DC electricity from solar energy to instantly cover the demands of the house, building or property.
The energy balance between solar generation and electricity demand is done every second. If the electricity demand is bigger than the solar generation, then power from the grid is used to cover that extra amount of energy needed.
On the other hand, if the solar generation exceeds the energy demands of your home, then the excess is exported to the grid.
If a blackout occurs in your area and you have a grid-tied PV system installed in your house, you may be surprised that you still won’t have electricity.
The reason is that the modules do not store energy, instead, they only serve as a converter of solar energy into electricity.
Now, you might be thinking that maybe if the blackout occurs during the day you might be able to have electricity while the sun is still shining.
However, the truth is that due to safety requirements, the local utility demands that all PV systems are disconnected from the grid at the moment of a blackout.
Therefore, your inverter will disconnect automatically and you won’t be able to use your solar electricity even if the modules are still generating energy.
How can PV systems protect me against blackouts?
The second type of system involves using energy storage devices.
Generally, nowadays it is common to find many PV systems that include lithium-ion batteries such as the Tesla Powerwall or the LG Chem RESU models.
These PV systems, commonly called Grid-tied with Battery Backup or Solar Plus Energy Storage Systems, have the capability to use the energy stored in batteries to work independently from the grid.
In the case of a blackout, the inverter must still disconnect itself from the grid due to safety requirements and will shut down.
But the difference here is that after a few seconds, the PV system will reactivate again and the inverter will establish its own frequency to use the energy stored in the battery.
This allows it to supply critical loads under contingency events.
In other words, the system will be able to work off-grid for as long as the blackout lasts.
As we have examined, not all solar panel systems are able to protect you against a blackout.
Actually, it is important to remember that the solar panel by itself does not store energy.
Instead, it is the combination between modules and batteries that can provide you with reliable electricity during those times when the grid is not available.
Using solar panels without battery backup guarantees that you will have increased independence from the grid to generate your own electricity while reducing costs.
At the same time, installing energy storage devices that can work off-grid will protect you against blackouts by storing and using the energy generated by the solar panels.
Keep in mind that not all energy storage devices can work off-grid (some only work for self-consumption) so you must make sure that your batteries will be able to provide blackout protection.
For more, visit How Solar Works.