How Battery Energy Storage Systems Work with Solar

Solar power has become more affordable, accessible, and popular in the United States than ever before. At SUNation Solar Systems, we are always looking for new innovative ideas and technologies that can help us solve problems for our customers. Battery energy storage is one of those technologies. 

What Are Battery Energy Storage Systems?

Battery energy storage systems are rechargeable battery systems that store energy from the solar system  and provide that energy to a home or business. Because of their advanced technology, battery energy storage systems store surplus energy produced by solar panels, power your home or business off-grid, and provide emergency backup power when needed.  

How Do They Work? 

Battery energy storage systems  work by converting the DC energy being produced by your solar panels and storing it as AC power for later use. The higher your battery’s capacity, the larger the solar system it can charge.

Ultimately, solar batteries do the following:

  1. Charge. During daylight, the battery storage system is charged by clean electricity generated by solar.
  2. Optimize. Intelligent battery software uses algorithms to coordinate solar production, usage history, utility rate structures, and weather patterns to optimize when the stored energy is used.
  3. Discharge. Energy is discharged from the battery storage system during times of high usage, reducing or eliminating costly demand charges.

When you install a solar battery as part of your solar panel system, you can store excess solar electricity instead of sending it back to the grid. If the solar panels produce more electricity than what is being used or needed, the excess energy goes towards charging the battery. Electricity will only go back to the grid when your battery is fully charged, and electricity will only be drawn from the grid when the battery is depleted. 

What’s the Lifespan of Solar Batteries?

The general range for a solar battery’s lifespan is between 5 and 15 years. However, proper maintenance can also have a major effect on your solar battery’s lifespan. Solar batteries are significantly impacted by temperature, so protecting your battery from extreme temperatures can increase its lifespan. 

What Are the Different Types of Solar Batteries?

Batteries used in residential energy storage are typically made with one of the following chemical compositions: lead acid or lithium ion. Lithium ion batteries are often considered to be the best option for a solar panel system, though other battery types can be more affordable.

  1. Lead acid batteries have a relatively short life and lower depth of discharge (DoD)* than other battery types, and they are also one of the least expensive options currently on the market. For homeowners who want to go off-the-grid and need to install a lot of energy storage, lead acid can be a good option.


*DoD indicates the percentage of the battery that has been discharged relative to the overall capacity of the battery. For example, if you have a Tesla Powerwall that holds 13.5 kilowatt-hours (kWh) of electricity, and you discharge 13 kWh, the DoD is approximately 96 percent. The more frequently a battery is charged and discharged, the shorter its lifespan will be. Many battery manufacturers specify a maximum recommended DoD for optimal performance.

Tesla Powerwall and Battery Storage

The Tesla Powerwall is a solar storage battery that allows you to maintain a sustained power supply, day or night. On a typical day, Powerwall will meet all of your home’s energy needs. A self-powered home combines solar energy and Powerwall to independently power. Powerwall integrates with your solar system to store excess energy produced during the day and makes it available only when you need it. Not only is Powerwall weatherproof, but it’s also a completely automated system that requires no maintenance. 


Best of all, the Powerwall can detect power outages, disconnect from the grid, and automatically become your home’s main energy source. Powerwall is then able to offer your home seamless backup power in a fraction of a second; your lights and appliances will continue to run without interruption. Without Powerwall, solar will shut down during an outage. Through the Tesla appl, you will have full visibility into your self-powered home. 

How Can SUNation Help?

As you consider your storage-plus-solar options, you’re likely to come across a lot of complicated product specifications. The most important ones to use during your evaluation are the battery’s capacity & power ratings, DoD, round-trip efficiency, warranty, and manufacturer. At SUNation Solar Systems, our team of solar panel experts can help you choose the best system for your home or business. Call us today at (631) 750-9454 or contact us online for more information on battery storage systems. 

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How Battery Energy Storage Systems Work with Solar



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