Solar panels are wonderful for turning sunlight into energy. What they are not good at is storing energy for later. Sometimes, there is no sunlight for the panels to convert. How do you get electricity for your home at those times?

Enter the battery. This is what people use to store extra energy the panels take in and use them at another time. It is especially helpful if your home or business is off the electrical grid.

Batteries only have a certain amount they can retain before they are fully charged and no longer have the capacity.  So, what happens to the extra energy? Depending on your set up, there are multiple places that energy can move to.

solar system


To understand how much capacity your battery has, find out the voltage. This will tell you how much charge it needs before it is considered full. Once that happens, the extra energy will be sent to the inverter.

The inverter is what helps the solar panel’s energy power your home. When the current is taken in from the solar panels, it creates direct current (DC) electricity. This current will not power your home right away, however.

It needs to first be converted into alternating current (AC). Once this happens, you have an electric current that can power your home. Some of this extra power gets used to help the inverter make its conversion.

The Electrical Grid

If your solar panels have collected enough energy to completely power your home and charge your storage battery, with some leftover, the extra will get sent to the electrical grid. This is a big draw for people using solar energy in the first place.

The electrical grid is the main hub for distributing electricity to homes and businesses. When you had no solar panels, your home was completely reliant on the electrical grid.

You can choose to be on or off the grid as a solar panel owner. The benefit of being on the grid is never having to worry about not getting enough solar power. When that system fails, the electrical grid is a back-up and vis versa.

When you are on the grid, a net meter gets installed to record your solar use. With this meter, extra solar energy gets sent back to the electrical grid. The electric company then credits the homeowner for their energy and they can use these credits on a future bill, saving you some money.


If you choose to be off the grid, you are totally reliant on your solar power set up to power your home. People often choose this as a way to create less greenhouse gas emissions. But because the grid is no longer your back up, where does that extra energy go to?

This system has no back-up solution, which means more storage options are needed to power your home at night or on a cloudy day. For homes that are on the grid, any storage batteries used are smaller. They are used to get you through a few hours of solar energy drought before the electrical grid kicks in.

Homes that are off the grid have storage batteries with a much higher capacity. This means all of that extra energy from the panels is going to get those batteries to a full charge. Because they take in much more, they also take much longer to charge.

Can my battery overcharge?

A big concern with any battery is the possibility of overcharging. This can make the battery have a shorter lifespan or overheat. We established that extra energy gets switched over to the grid or other solar equipment, but how?

This is where the solar charge controller comes into play. This device is used to help regulate storage energy. It sends power to the battery, and when the battery reaches capacity it is able to shut the current flow off and redirect it.

If the battery is chronically undercharged, this can also create problems with its performance. You risk the same issue of a shorter life expectancy. 

This solar charge controller is doubly important for this reason. It can maintain the correct levels of charge for the battery without exceeding it. Once the battery is under control, it then diverts the extra energy to whoever needs it next, depending on your setup.

The process of creating solar energy can be deceptively complex, and the battery is an essential component of that system. While maintaining the energy levels for it are important, what happens after the battery is charged is just as essential. Understanding this could even help you save money in the end.

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