You have heard about or seen solar panels powering homes with sunshine, but energy storage is not as well known. Batteries are an important part of a home solar system. They store extra electricity to use when solar power is low, like on cloudy days, during outages, or at night.

How Do Batteries Work?

When solar panels generate more electricity than your home uses, batteries store the extra energy for later. This also guarantees a steady electricity supply throughout the year.

Lithium-ion batteries, like phone batteries, are the most common form of solar storage on the market. Inside the battery, chemical reactions store surplus electricity as potential energy, which can then supply your home on-demand.

Are Solar Batteries Worth It?

There are various advantages to batteries. In some areas where demand charges are factored into electrical rates there can be financial benefits to invest in batteries. The financial benefits in Wisconsin are not as significant. Batteries are not typically considered for a financial return, but rather for the resiliency and protection battery storage offers your home from the disruption of a grid outage.

Cons

Batteries allow you to maximize the benefits of your solar system and reduce your reliance on the grid. They also offer maintenance-free backup power during blackouts and help you store more of your solar energy for use when sunlight is low.

However, there are some cons involved with solar batteries:

• Cost 

   
  

Energy Storage is an investment. Battery installation costs over $10,000, but with 30% federal tax credits, your system can pay for itself faster.

• Space 

   
  

To store your excess power, the Tesla Powerwall 3 measures about 3’7″ x 2’5″ x 6″ and weighs 287 pounds. With Wisconsin’s variable weather, batteries work best when installed indoors in a garage or basement. Some municipalities, like Dane County, require battery storage rooms as an extra layer of safety.

• Limited capacity
  
  

Energy storage has a limit on how much power it can hold, it may not last more than 24 hours for your entire house. This depends on how much energy you use daily.

Can I Add Battery to My Existing Solar?

Absolutely! Installing batteries with solar panels at the time of installation is often easier and cheaper. However, you can usually add batteries to existing solar systems.

Depending on the battery, you may need a separate AC coupler. However, modern batteries like the Tesla Powerwall 3 and Franklin Whole Home can store solar power without extra adapters.

How Long Do Batteries Last?  

The warranty on most home solar storage batteries is between 10 and 12 years. Experts expect lithium-ion batteries, the latest technology, to last between 10 and 15 years. Assuming no damage, regular mild cleaning, and proper ventilation, batteries can outlast their warranty.

Will Batteries Ever Be Obsolete?

Experts do not project that anyone will replace lithium-ion batteries any time soon. Lithium-ion batteries provide up to ten times longer life than lead-acid batteries and last over twice as long.

Why Homeowners Are Turning to Battery Storage  

Resiliency and maximizing the benefit of your solar production are the top reasons customers show interest in batteries.  

Storage might not be suitable for every home. However, when it is a good fit, it can significantly enhance benefits and energy independence.  

Does Solar NEED a Battery?  

Battery storage offers many benefits when paired with home solar installations, but it is not a necessity. High initial costs and limited backup capacity can make solar storage unsuitable for some situations.  

In Wisconsin, utility companies pay solar customers low rates for extra electricity. This makes it hard for homeowners to profit from generating more electricity than they use. They can only do so if they have a way to store the extra electricity.  

Arch’s engineers create systems without batteries to match 100% of production throughout the year. The main benefit of a battery for a Wisconsin home is power backup, not financial gain.  

As our weather continues to change, having peace of mind and ensuring crucial items do not turn off is often reason enough to pursue energy storage.   

Blackouts/Demand Usage  

If you are concerned about blackouts or want to use clean energy, batteries are a good option. They can provide backup power for your home without relying on fossil fuels. In Wisconsin, falling trees, heavy snow, and animals interfering with power lines often cause service interruptions.  

Another point about needing batteries is energy demand. Large homes which need a lot of heating/cooling naturally have a high energy demand. Other standard appliances include water heaters, lights, refrigerators, and so on. Hot tubs and pools increase electrical usage, and you can offset this with solar and solar energy storage.  

EVs

Batteries can be used to send power to both your home and your electric vehicle.  

Certain model EV’s equipped with bidirectional charging (two-way) can also use additional stored solar power, acting as a secondary power source in case of emergencies or to reduce energy demand taken from the grid.  

This enables the EV to function like a battery to increase power demand self-sufficiency, especially when combined with rooftop solar.  

Read more about bi-directional charging from cleanenergyreviews.  

How To Choose the Right One for Your Home  

Choosing between the Tesla Powerwall 3 and the Franklin Whole Home battery depends on a few factors. First, consider your energy needs. Then, think about your budget. Finally, evaluate your storage goals.

Tesla Powerwall 3

• Capacity – 13.5 kWh/unit  

• Power Output: 5 kW continuous, 7 kW peak  

• AC Coupled: integrates into existing system.
  

Franklin Whole Home

• Capacity – 13.6 kWh/unit  

• Power Output: 5 kW continuous, 10 kW peak  

• AC or DC Coupled: offers more flexibility.
  
  

Both companies include monitoring software to see your battery performance or tweak settings on the fly.  

One other major consideration is that Tesla batteries have stronger integration with Tesla EV’s. If you are not considering a Tesla EV or any EV, the comparisons between the two are quite similar. However, the Franklin WH has a stronger output and can handle higher energy demands when on battery power.
  

Conclusion  

Solar battery backup is a smart investment for those who are looking to get the most out of their home solar system. Battery storage enables you to utilize your solar production during a grid outage and minimizes your reliance on the grid. Stronger protection against rising electrical rates and grid outages is added assurance for your household.  

Now is an exciting time to talk to a solar installer in Wisconsin. You can save 30% on your complete system, including batteries, with the Federal ITC Tax Credit.  

Read more about energy storage systems with Arch.