When City Grid goes out, for homes that do not have a solar system, that is a definite blackout because they get their power source exclusively from City Grid.
However, for homes that have solar systems, why do they also have blackouts? But why is it that some homes that have solar systems installed as well don’t have power outages. It depends on the type of solar system you have installed and whether it is connected to an external power source or not.
1. The effect of the type of solar system connection on whether the solar system will supply power after a blackout
1.1 Grid-tie system:
This is the more common way of installing a solar system. The grid-tied inverter in a grid-connected system converts the DC power generated by the solar panels into AC power and connects it to the city grid. This delivers excess power to the grid.
The grid-connected inverter has a built-in anti-islanding protection device, which automatically shuts down when it detects a power outage and stops delivering current to the grid, preventing the current from harming the people who are servicing the circuit. So in case of power failure, the solar system in the grid-tied system will not be able to supply power to the home.
1.2 Off-grid system:
The inverter in an off-grid system is different from the inverter in a grid-connected system in that it is unable to deliver the excess power generated by the solar energy to the grid company. So even though there is still power available for the solar batteries when they are full, the energy supplied by the solar system can only be reduced by transformer step-down. As a result, grid outages have little effect on homes with off-grid solar systems.
1.3 Hybrid Grid System:
A hybrid grid system functions as both an off-grid system and a grid-connected system, and it can both charge the batteries and deliver power that is fully charged for the batteries to the grid company. Although it also has the function of delivering power to the grid company, in the event of a power failure, the hybrid inverter will automatically switch to off-grid mode and stop delivering current to the utility. Therefore, the hybrid system can supply power to the home during a power outage.
2. Why is it prohibited for the inverter to deliver power to the grid company after a blackout?
As mentioned above, in order to prevent excess power from being sent to the grid, there is a special automatic shutdown device in both the grid-connected system and the hybrid system after a power outage. So why is this so?
That’s because immediately after a power outage, maintenance workers will make repairs to the city’s power grid, and this device is in place in order to protect the safety of the maintenance workers and to prevent current from flowing into the grid company’s power lines, which can cause danger.
As a result, homes with grid-tied solar systems will also lose power. For homes with hybrid grid solar systems, the power does not go out for the time being because it has a battery. For off-grid systems, whether or not there is a power outage has little to no effect on its operation.
3. How can a home with a grid-tied solar system not lose power during a blackout?
3.1 It’s easy to convert your grid-connected solar system to a hybrid solar system, add batteries to your solar system, and you’ll be able to survive a blackout. However, it’s not so cheap.
3.2 Use a backup generator, e.g. gas generator, solar generator.
3.21 A gas generator can power your entire house simply by adding fuel to it when the power goes out. However, it is noisy and smells bad to pollute the environment.
3.22 A solar generator is used as a portable device that can supply power at any time of the day. It can be charged when it is solar powered. However, it has a small storage and may supply only up to refrigerator and few household appliances in case of power failure.
4. Specialized inverter.
With the development of technology, a special solar inverter has been produced which can be automatically disconnected from the grid in case of a grid outage, so that there is no need to install a solar system with a special automatic shut-off device that prevents the solar energy from supplying power.
5. Are solar systems worth our while?
There’s no doubt about it. Even though a home with a grid-tied solar system will lose power when the grid goes down, there are still plenty of ways to get electricity to get through the blackout crisis. Now that technology is getting more advanced, I’m sure more and better solutions can be found in the future. And for homes that install hybrid and off-grid solar systems, power outages have almost no effect on them. So installing a solar system is still very cost-effective and the convenience it brings to us is perfect in every way.
