Complete Guide to Solar Battery Backup
If you’re thinking about installing home solar panels, you should also be considering battery storage.
Solar batteries make it possible to use solar energy not just when the sun is shining but at any time, including at night and during a power outage.
At Sustainergy Cooperative, we install solar plus battery systems that help you get more out of your solar investment. In this guide, we cover all the basics to help you decide whether a solar battery is worth it for your home.
How Do Solar Batteries Work?
Solar batteries work by storing solar energy so you can use it to power your home at any time, not just when there’s sunlight.
During the day, residential solar panels often produce more electricity than your home uses. In a standard grid-tied solar panel system, the excess is sent to the electric grid. With a battery, you can store your excess power instead.
When your solar panels aren’t producing enough power (like at night), you can use your battery instead of buying electricity from your utility.
You can also use your battery as a backup power source during a grid outage. If you don’t have a battery, your solar panels will automatically shut down during a power outage. This is a safety precaution that stops them from sending surges into the grid while it’s being repaired. A battery allows your panels to temporarily disconnect from the grid so you can continue to use them during an outage.
What Are the Benefits of a Solar Battery?
Solar batteries have three main benefits.
Backup Power
When the grid goes down, your solar battery can keep essential appliances like your fridge, lights, or medical equipment running without relying on a noisy, dirty gas generator.
2. Electric Bill Savings
Solar batteries let you use more of the electricity your solar panels generate. With net metering on the chopping block in many states, this is more important than ever for your electric bills.
In the past, you could send excess power to the grid and get paid the full retail rate to offset your future grid usage. But that incentive is gone in Kentucky and under attack in Ohio.
A battery lets you hold onto your excess power so you can use it yourself at night and on cloudy days instead of buying power from your utility.
3. Energy Independence
Solar plus storage systems give you as much control over your home’s energy as possible without going fully off-grid. It makes you less reliant on your utility company and ensures a stable, secure electricity supply for your home.
Solar Battery Lifespan & Maintenance Requirements
Solar battery lifespan is usually about 10-15 years, though they can last longer if you take good care of them. As your battery gets older, it will start to degrade, which means it won’t be able to hold a charge for as long. This is normal, and most battery warranties promise a certain level of performance at the end of the term, like 80% after 10 years.
Here’s what affects battery lifespan:
Chemistry - Lithium-ion batteries, for example, typically last longer than other options.
Usage - Your battery will degrade slowly with every charge/discharge cycle, but there are things you can do to slow it down. For example, avoid deep discharges (draining your battery all the way). Frequent deep discharges will shorten its lifespan.
Environment - Heat, humidity, and moisture can all take their toll. That’s why we recommend installing your battery somewhere with protection, like a garage.
Solar battery maintenance is straightforward. There’s not much you need to do, but taking good care of your battery will help it last longer.
Here are some maintenance tips:
Follow manufacturer instructions - Maintenance will vary by make and model, so make sure you check your manufacturer’s guidelines.
Avoid deep discharges - Draining your battery all the way too often can shorten its lifespan.
Monitor performance - Your battery will come with a monitoring app that you should use to keep an eye on its performance.
How Much Do Solar Batteries Cost?
Solar batteries are not cheap, but they’re getting more affordable. The cost can vary depending on:
Make & Model - There are several battery brands on the market and most of them offer a variety of models, all with varying price points.
Storage Capacity - The more storage capacity you install, the more expensive your system will be.
Installation Complexity - Costs can be higher if you need extensive electrical work like a panel upgrade.
Incentives - Solar batteries qualify for a 30% tax credit, bringing the cost down significantly. But this tax credit could be going away soon! Schedule your installation now to take advantage of savings before it’s too late.
Is a Solar Battery Worth it for Your Home?
Like most home upgrades, solar batteries have their pros and cons.
Cons:
They’re expensive and don’t last forever.
Pros:
They provide reliable backup power, giving you peace of mind during an emergency. And, they can save you money on your electric bills, especially as rates continue to increase, more and more utilities shift to time-of-use pricing, and net metering programs are phased out.
At Sustainergy Cooperative, we help our customers make the best decisions for their specific needs. We’ll talk to you about your goals and help you decide whether a solar plus storage system is the right way to achieve them.
