To answer this question, we must first understand that there are different definitions of a normal inverter. Some want a solar power system that can send electricity to and from the grid. These people see a grid-tie inverter as a normal inverter. Some either cannot connect to the grid, or don’t want to. These people consider an off-grid inverter to be normal. So, we must consider this when we point out the differences between a normal inverter and a hybrid inverter. With this in mind, the quick answer is that a hybrid inverter can act as both a grid-tie and off-grid inverter. We will look at this in more detail.
A hybrid inverter is more independent than a grid-tie inverter.
A grid-tie inverter works as a current source and is a grid-following inverter. A grid-following inverter needs to sense an AC voltage source before it can produce any power. This means that a grid-tie solar power system will lose power if the grid loses power. This prevents the inverter from sending power to the grid when utility workers are working on the power lines, but it means that loss of grid power will cause your home to lose power.
A hybrid inverter does not need a signal from the grid to produce its own AC power, but it can synchronize with the grid to connect with it. A hybrid inverter also has a built-in transfer switch that will disconnect it from the grid and the main circuit breaker panel if the grid loses power. If that happens, it will operate separately from the grid and power the critical loads. These critical loads are the electrical equipment you need, and the hybrid inverter will power them as an off-grid inverter would. This is because a hybrid inverter has greater independence than a grid-tie inverter.
A hybrid inverter is more interactive than an off-grid inverter.
An off-grid inverter can operate without the grid, but that is all it can do. If there is an issue with the solar panels or with the batteries, you are on your own. Also, a shortage of stored energy is one of the major issues to face with off-grid systems. So many off-grid systems have huge battery banks, which makes them very expensive.
Although a hybrid inverter can operate without the grid, it can also interact with the grid whenever necessary. It can take AC power from the grid and turn it into DC power to charge the batteries. This lets you start with a smaller battery bank and add to it later. A hybrid inverter can also sell excess energy back to the grid. You cannot do this with an off-grid inverter.
A hybrid inverter is multi-functional.
Unlike a grid-tie inverter or an off-grid inverter, a hybrid inverter can do more than convert DC to AC. A hybrid inverter can also deliver energy from any source in your system to anything that can accept it. So, here is what it can do:
It can send energy from the solar panels to the batteries.
It can send energy from the solar panels to the grid.
It can send energy from the solar panels to the loads.
It can send energy from the grid to the batteries.
It can send energy from the batteries to the grid.
It can send energy from the grid to the loads.
It can send energy from the batteries to the loads.
A hybrid inverter can do more than transfer energy from one component to another. It can also monitor your solar power system and show its status. This is why the hybrid inverter is usually the control and monitoring center for a hybrid solar power system.
A hybrid inverter allows you to change your solar power system.
A hybrid inverter can work with or without batteries and can function with or without the grid. The ability to function in these configurations also allows you to switch your system from one configuration to another.
For example:
You can start off with a system that has no batteries and is connected to the grid, which acts like a grid-tied system. You can then add a few batteries and put some of your circuits on a critical loads panel, which gives it battery backup during a grid outage. You can then add several days’ worth of batteries and include all your circuits on your critical loads. After that, you won’t need the grid. You can then disconnect from the grid, which renders your system an off-grid system. This helps because it allows you to add batteries when you can afford them instead of all at once.
If you tried to do this with a grid-tie inverter, you would need an AC transfer switch to disconnect your system from the grid. You will also need a grid-forming inverter to lead your grid-tie inverter. On that note, a hybrid inverter is a grid-forming inverter that has a built-in AC transfer switch. Now some AC-coupled batteries have built-in grid-forming inverters. But if you use one of them, you will still need an AC transfer switch. Also, the AC coupled battery needs to accept a charge while providing an AC signal. Otherwise, it will discharge, and your system will stop working.
A hybrid inverter lets you choose how to interact with the grid.
A grid-tie system can only sell to the grid during the daytime when there is a surplus of solar energy. When the sun goes down, it must buy from the grid to meet electricity needs. Also, utility companies raise rates in the evening when the usage is highest. This can reduce the savings made with grid-tie systems.
A hybrid system lets you save surplus energy from the daytime to use in the evening and nighttime. The only requirements are that you collect surplus energy and have enough battery capacity to store it. If you have enough stored energy, you can even sell back to the grid during the evenings.
A hybrid inverter gives better energy security.
A hybrid inverter can use the grid if some components of your solar power system happen to fail. It also lets you power your home if the grid fails. This flexibility allows you to power your home in more scenarios than with either a grid-tie or off-grid inverter. This translates to better energy security.
In summary, a hybrid inverter is multi-functional, unlike a grid-tie or off-grid inverter. This allows the hybrid inverter to interact with the grid, unlike the off-grid inverter. The hybrid inverter is also independent of the grid, unlike the grid-tie inverter. So, the hybrid inverter lets you choose how to interact with the grid. It even allows you to change your type of solar power system. A hybrid inverter also gives better energy security than either a grid-tie or off-grid tie inverter.