The rise of home solar panel installations, has sparked interest in another technology: solar batteries that can store electrical energy for use at a later time.

In a typical solar energy system, power production varies throughout the day. When your solar panels are producing more electricity than necessary to power your home, that excess power is sent back into the local grid. On the other hand, if your panels are not producing enough electricity for your needs, you can draw power from the grid.

Most of the time, with net metering, you will receive a credit for any electricity you send back to grid. This credit can be used later, when you are not producing enough electricity to power your home.

Curious to know where solar batteries fit into all of this? Read on to learn about how a home solar battery works, and find out if installing a solar battery is worth it for you.

How Solar Batteries Work

During sunny daytime hours, a solar PV system produces direct current (DC) electricity. Solar batteries store the DC electrical power in chemical form for use at a later time. Since most solar panel systems generate a varying supply of power during the day, a battery storage system is a reliable solution, as it can offer a constant source of power even during periods of minimal production. The higher your battery’s capacity, the bigger its ability to supply your home with power.

Electricity generated by your solar panels is sent to the battery for storage, and is then used by appliances in the home when needed. Once the battery bank is full, it will stop receiving power from your PV system. The higher your battery’s capacity, the greater its ability to supply your home with power.

A solar battery minimizes and in some cases eliminates a home’s reliance on the public utility grid.  Any time your system would be drawing power from the grid, like during the night, on cloudy days, or days when you are using more electricity than your panels have produced, the battery will serve as the power source. You will still send electricity back to the grid when your battery is charged to the max, and you will only need supplemental electricity from the grid when your battery is depleted.

Keep in mind that solar batteries are not 100% efficient, as some energy is always lost in chemical reactions during charging/discharging. Because of such inefficiency issues, it is generally recommended to add solar panels to your system to compensate for battery loss if you are not connected to the grid.

Is Installing a Solar Battery Worth it for You?

A simple grid connected PV system does not need a solar battery to function. Essentially, the local grid is used like a battery, with the home solar system drawing power from the grid when there is not enough energy production to cover the home’s needs. Don’t want to rely on the grid alone for supplemental power?

Here are several reasons you may want to consider a solar battery addition to your solar panel system:

1.  You want to store the energy generated by your solar panels during the day and use it when the sun is not shining.

Whether for political, social, economic, or individual reasons, if you like the idea of personal sustainability, the ability to use your own power without relying on an outside source may be appealing to you. Home storage systems for solar power empower you to live independently, taking personal responsibility for your energy needs.

2.  Your utility offers limited net metering, or no net metering at all.

Though most states have some net metering laws or other forms of regulation, net metering policies still vary depending on where you live. If you are not satisfied with your net metering agreement, or feel like you are not getting a fair value for the extra electricity you produce, it might be good to consider keeping more of your power with a home battery.

3.  You want to have backup power available in case of a blackout.

During a power outage, Solar panel systems that are tied to the grid automatically shut off for safety reasons. If you have a solar battery, you will be able to have a steady supply of power even

Many people considering going solar ask if a solar system works during a power outage. If you have a solar battery system as well as a solar PV system, your power will continue to work. However, since your system is grid-tied, for safety reasons, if there is a power outage your solar system will automatically shut off when the power goes out. Solar batteries can add as much as 30% to the cost of a solar system presently, so most homeowners do not go with this option.

4.  Your utility has sneaky time-of-use rates that charge more during periods of high demand.

Most utility companies charge varying rates depending on how high demand is at any given time. Rates are usually lower during off-peak periods, and increase during periods of high demand. Usually, homeowners are encouraged to shift electricity use to off-peak times to avoid an increase in their bill. If you want more flexibility to use electricity whenever you want without worrying that it will cost you more, a battery storage solution can give you that constancy.

5.  You live off-grid, and your property is not connected to a utility.

If you are considering going off-grid and relying on solar power completely for all your energy needs, keep in mind that an off-grid system will be more expensive than a hybrid system which utilizes a battery while still being connected to the grid.