Solar batteries can keep your power on during blackouts, power your home with solar energy at night or on cloudy days, and in some cases, can reduce your energy bill. These systems offer peace of mind and energy independence, making the investment worth it for many homeowners.
That said, solar systems do not require a solar battery. Keep reading to learn more about the benefits and other considerations of solar batteries, and decide whether a solar battery is a worthwhile addition to your solar panel system.
How do Solar Batteries Work?
Solar batteries store excess energy generated by your solar panels during the day. You can use this stored energy to power your home at night, on cloudy days, or during emergencies like a power outage.
Without a solar battery, any energy from your solar panels that is not used immediately by your household is sent back to the utility grid to be distributed to your community. With a solar battery, this excess energy is captured and stored for your home to use later.
Types of Solar Batteries
Although there are several types of solar batteries available on the market today, the two most common types for residential solar installations are lithium-ion and lead-acid batteries.
Lithium-ion batteries are the most popular solar batteries for home use thanks to their lightweight material, ample lifespan, and high efficiency.
Lead-acid batteries are a slightly older backup power technology. This type of battery has a shorter lifespan, is heavier, and takes longer to charge than lithium-ion batteries. On the plus side, lead-acid batteries are reliable and cheaper than lithium-ion batteries.
The Benefits of Solar Batteries
Adding a battery to your solar system allows you to store backup energy for use in emergencies, which can provide stability and energy savings.
Keeping Power on During Outages
A solar panel system without solar battery storage is not immune to power outages, even if the sun is shining.
Remember, without a battery, residential solar panel systems send excess energy back to the power grid. If your energy company is restoring power to your area, and a crew is working on the power lines, any energy flow presents a safety risk. For this reason, the power company will shut down everything that’s live on the grid — including your solar system.
A solar battery system allows you to store excess energy to use during power outages. Although it depends on your energy consumption and battery capacity, a typical solar storage setup can power your home, including most household appliances, for several hours. The more battery storage you have, the longer you can keep your home running without power.
Achieving Energy Independence
Any solar panel system will help you achieve some amount of energy independence, as you won’t have to worry much about the rising cost of traditional power. Installing a solar battery can further your energy independence.
Using solar to completely disconnect from the energy grid and achieve 100% energy independence may be possible — if your local laws allow it. But it may not make sense financially. Rural homes with an unreliable energy supply or very high electricity costs are most likely to benefit from a fully off-grid home solar system. That being said, a completely off-grid system is not recommended for most homes.
Saving Money on Your Electric Bill
Net metering allows you to earn bill credits for the excess energy your panels generate during the day. If you do not have access to a net metering program, you will have to pay for the energy your household uses at night and when your solar panels aren’t generating power. If your utility company does not offer a full retail-rate net metering program or charges time-of-use electricity rates (where you pay more for power during peak hours), a solar battery may help you save money on your electric bill.
If you have a solar battery, you can avoid these costs by storing your panels’ excess energy to use during peak times.
Your solar installer will be familiar with local policies, so you can speak with a representative to determine if a solar battery will help you save each month.
Other Solar Battery Considerations
When deciding if a solar battery is the right fit for your household, you’ll need to consider the cost, capacity, and lifespan of your energy storage system.
Return on Investment
In most cases, the upfront cost of a solar battery is higher than the energy savings you will see over the battery’s lifespan. But as solar battery technology advances, battery prices fall, and government and utility policies change, storage systems are becoming more attractive investments.
To power your home for several days during an outage, a single solar battery probably won’t cut it. An average-sized 10 kilowatt-hour (kWh) solar battery may only run your home for a few hours of regular consumption, or up to 24 hours if you significantly conserve energy.
You can install multiple solar batteries to power your home even longer, but this is prohibitively expensive for many homeowners.
Solar batteries have a shorter lifespan than solar panels, meaning you’ll likely need to replace solar batteries before the rest of your solar power system.
Most solar panels come with a 25-year product warranty (and will still operate for years after the warranty’s expiration). Solar batteries typically come with a 10-year warranty and have limited lifespans.
For example, lithium-ion batteries, the most common type of solar battery on the market today, have a typical lifespan of 4,000 cycles. If the battery completes one daily charging cycle, it would last around 11 years before needing replacement.
How Much do Solar Batteries Cost?
According to the U.S. Office of Energy Efficiency and Renewable Energy, adding a solar battery to an existing solar panel system can cost between $12,000 and $22,000. Popular solar batteries like the SunPower SunVault fall within this cost range, starting at around $17,000 with battery installation. Blue Raven Solar installs SunPower SunVault batteries in select markets, including Utah, North Carolina, Nevada, Idaho, Colorado, Washington, and Oregon.
The brand, type, and capacity of the solar battery you choose will influence the total cost. You can speak with a Blue Raven Solar expert about your personal energy goals and needs to determine how much your solar energy storage system will cost.
Will a Solar Battery Save Me Money?
When it comes to solar panels, the average homeowner will see a return on their investment within six to nine years of installation. But is the same true for solar batteries? The answer is a little more complicated. Whether a solar battery will save you money largely depends on the policies and programs available in your area.
New developments in solar battery technology and changing net metering policies mean solar batteries are more likely to save you money than ever before. Despite this, solar batteries are not yet cheap enough to break even in most instances.
What to Consider When Choosing a Solar Battery
Other than cost, it’s important to consider metrics like storage capacity, warranty, efficiency, and power rating when choosing a solar battery.
- Storage capacity: The storage capacity of your battery is measured in kWh, with the top solar batteries ranging from 9 kWh to 26 kWh of capacity. Batteries with a higher capacity are more expensive, but they can also power your home longer, so you can strike a balance between cost and capacity.
- Warranty: Most solar batteries come with a 10-year warranty. Some also include a guaranteed capacity warranty, which promises your battery will retain a certain percentage of its original capacity by the end of the warranty period. Some warranties limit the number of cycles your battery can discharge, so look for batteries with an unlimited-cycle warranty.
- Efficiency: Round-trip efficiency describes how much power is lost during your battery’s charging, storing, and discharging cycle. The higher your battery’s round-trip efficiency, the more power you’ll draw after a single charge. Most solar batteries on the market offer a round-trip efficiency in the 90% range.
- Power rating: A battery’s power rating represents the rate at which it can discharge stored power. Batteries with a high power rating can support higher energy needs.
Should I Buy a Solar Battery?
A solar expert can help you decide if installing a solar battery will help you achieve your goals. If you’re primarily interested in energy independence and keeping the lights on during an outage, a solar battery is likely a good investment.
If saving money is your top priority with installing a solar battery, consider your situation. For example, if your utility company charges higher rates during high-demand periods, or does not offer a good net metering program, your solar battery will help you save on energy costs. On the other hand, if you have access to full retail-rate net metering programs, using stored solar energy is less likely to reduce your utility bill.
When deciding if a solar battery is right for you, you can speak with your local utility provider and trusted solar company like Blue Raven Solar to understand how to get started.
Frequently Asked Questions
How many solar batteries are needed to power a house?
Depending on your solar battery’s capacity and your household energy usage, a single battery can power your home for several hours (up to 24 hours if you conserve your energy). To power your home longer, you can purchase multiple batteries.
Do I need a solar battery?
Solar panel systems don’t necessarily need a solar battery. However, you will need a solar battery if you want to go off-grid or store your solar panels’ energy to use when it’s cloudy or dark outside.
Do solar batteries qualify for the federal tax credit?
Yes. Solar batteries qualify for most solar incentives and rebates, including the 30% federal solar tax credit.
Will the battery work on days when it is not sunny outside?
Yes. When it’s nighttime or cloudy outside and your solar panels aren’t generating energy, your solar battery can power your home with stored energy.