How is Solar Energy Stored?

Here at A.M. Sun Solar we get one question over and over again. You’ve probably wondered about it too. Maybe your kids have asked you this. “Hey, how is solar energy stored?” It’s a reasonable question! After all, the sun doesn’t shine every day, and the peak times for energy use are summer evenings, after the sun goes down, when people are playing video games after work and turning on the AC. Solar energy may be good for the planet, and better for your energy bills, but if it wasn’t reliable, it couldn’t fit into our customers’ lives. Luckily, we’ve figured it out. We just use batteries.

What kind of battery?

Home solar systems usually use one of two kinds of batteries to store power: lead-acid and lithium-ion. You might be familiar with a lead-acid battery from something else in your life — it’s the OG car battery. Lead-acid technology is the OG battery, period: it powered the very first batteries in the 1800s. But lithium-ion is what George Crabtree, director of the US Joint Center for Energy Storage Research, called “the best battery technology anyone has ever seen,” in an interview with Nature. They’re the battery used in most consumer electronics and electric cars. On the whole, lithium-ion batteries provide more power and have longer lifespans than their lead-acid counterparts, but the upfront cost of a lead-acid battery is cheaper.

How does it work?

How does a solar battery work? It’s simple. It’s the exact same as charging any other device in your home. Light strikes the photovoltaic solar panel, creating energy, which is turned into direct-current power, which we don’t use in our power outlets. It goes through an inverter, which converts the direct-current into alternating-current, which we do use. Any excess gets channeled into the battery and stored for a rainy day. For a more in-depth explanation of the process, check out our blog post on the subject.

Do I need a battery?

Do you have to have a solar battery? No, not necessarily. But without a battery, you’re at the mercy of the elements. The sun goes down — it has to. The clouds come out — they have to. Even people in Yuma, the sunniest city on earth, get cloudy skies for 65 days a year. And if the power grid goes down, your solar system will too, to keep electrical workers safe while they fix the power lines. But solar batteries do have some trade-offs. You’ll need a little space when you’re trying to figure out where to install a solar battery. According to the National Fire Protection Association, you need to install your battery:

● In a garage

● On exterior walls (at minimum three feet from any doors or windows)

● Outside

● In a storage or utility space

And, batteries, like everything else in life, cost money. It costs, on average, $10,000 dollars to install a lithium-ion battery. Lead-acid batteries are cheaper, but on the whole, require more maintenance and need to be replaced more frequently. The good news is, the average lifetime savings of solar are up to $33,000, so these things pay for themselves across the lifetime of the system. If that’s not enough, the federal government offers a 30% tax credit on new solar systems, and your state government may offer one as well. But if a battery isn’t a good fit for you right now, your solar system will still work! You’ll just have to use what’s called a “grid-tied system,” drawing electricity from the regular power infrastructure when the sun’s not out.

Get in touch

If you’ve got an existing solar system, and you’re thinking about adding a battery to improve your system’s resilience, to help you get off the power grid, or to make sure you’re ready in case of an emergency, we offer free consultations! Our team is waiting to talk to you about the best energy storage solution for your needs. If you don’t have solar, but you’ve been thinking about it, we’d love to help you put together a plan to power your home or office. Ready to make the switch? Fill out the form below to schedule your FREE solar Consultation!

More about A.M. Sun Solar

A.M. Sun Solar is the local leader in custom solar solutions and installations on the Central Coast. For over 15 years, A.M. Sun Solar has provided high quality, cost efficient solar energy to residences and small businesses in San Luis Obispo, Monterey, and Santa Barbara counties. With a wide variety of financing solutions available, affordable pricing, custom solutions and complete installations from permit to interconnection, A.M. Sun Solar is the go to local solar company on the Central Coast.

Connect with us today at, (805) 772-6786, or fill out the form below to get a FREE on-site consultation with one of our friendly solar experts.