Choosing the Right Battery Backup for Your Solar Panels

Choosing the right products for a given home component is naturally important, and a great example here is found when selecting a home battery backup for a new or existing solar panel setup. Which key factors should you be considering as you choose the ideal solar battery backup for your needs?

At Intermountain Wind & Solar, we're proud to offer the very best solar power services to clients around Salt Lake City, Utah and Boise, Idaho, including home battery installation solutions that involve a few different solar battery backup products and options. Here are some of the chief factors our team will walk you through when it comes to choosing the right home battery backup for your system, whether it's an existing system or a brand new one.

Why a Home Battery Backup?

Before we get into the specific options for home battery backup products, let's first discuss why having a backup battery system is important.

• Power Outages: One of the most common reasons for wanting a home battery backup is to have power during an outage. Whether it's due to severe weather, equipment failure or other issues, power outages can leave you and your family in the dark and without essential appliances for extended periods of time. A home battery backup ensures that you have access to electricity even when the grid goes down.
• Energy Independence: With a home battery backup, you are no longer solely reliant on the grid for your energy needs. This means that you can generate and store your own electricity using renewable sources such as solar panels. This not only reduces your dependence on fossil fuels, but it also gives you more control over your energy usage and costs.
• Sustainable Energy: By using a home battery backup in combination with renewable energy sources, you are able to significantly reduce your carbon footprint. This is because the electricity generated from solar panels or wind turbines doesn't produce harmful emissions like traditional power plants do.
• Cost Savings: While the initial cost of installing a home battery backup may seem high, it can actually help save you money in the long run. With this system in place, you can store excess energy during off-peak hours when electricity rates are lower and use it during peak hours when it's needed. For many homeowners, the biggest benefit is still having reliable backup power in case of emergencies and greater energy independence from the grid.

Now let's look into some of the chief factors to consider when choosing the right solar battery backup for your setup.

Compatibility With Panels

Naturally, one of the simplest but most important factors to consider is the compatibility of your solar battery backup system with your existing solar panels. Most commonly, these systems are designed to work with standard size and output panels, but it's always best to double-check before making a purchase. If you plan on adding more panels in the future, make sure that the system can accommodate them as well.

Capacity

The capacity or storage capabilities of a battery backup system is another crucial factor. This determines how much energy can be stored and used during power outages. Typically measured in kilowatt-hours (kWh), the higher the capacity, the longer your batteries will last when powering essential appliances and devices.

For example, the Tesla Powerwall 3 has a 13.5 kWh usable capacity, which is enough to back up most essential home loads like your fridge, lights, internet, and outlets for multiple hours, or even longer when paired with solar to recharge during the day. It also delivers up to 11.5 kW of continuous power output, meaning it can support larger appliances like central AC or well pumps without overload. We offer these batteries at IWS among a variety of others. Just ask!

Depth of Discharge

When we talk about battery backup systems, we often hear the term "depth of discharge" or DoD. This refers to the amount of energy that has been drained from a battery as a percentage of its total capacity. For example, if you have a 10kWh battery with a 50% DoD, it means that you can only use up to 5kWh before the battery needs to be recharged.

Understanding the depth of discharge is essential because it affects the lifespan and performance of your batteries. A higher DoD means more frequent charging cycles, which can decrease your batteries' overall lifespan. On the other hand, a lower DoD allows for longer periods between charges and extends the life of your batteries.

Cycle Life

Another important factor to consider when it comes to battery performance is its cycle life. Cycle life refers to the number of charge-discharge cycles a battery can undergo before its capacity drops below a certain threshold.

The cycle life of a battery depends on various factors, such as depth of discharge, temperature, and charging methods. Generally, the deeper the discharge and the higher the temperature, the shorter the cycle life of a battery.

Therefore, it is crucial to carefully manage your batteries' DoD and ensure they are not exposed to extreme temperatures for extended periods. This can help prolong their cycle life and save you money in the long run by avoiding frequent replacements.

The Tesla Powerwall 3 is designed for a cycle life of approximately 6,000–10,000 cycles, depending on usage patterns, temperature, and depth of discharge (DoD). For a typical homeowner using one full cycle per day, that translates to 15+ years of daily use while still retaining most of its original capacity.

Battery Brands Available

We offer a variety of batteries at IWS such as:

• Tesla Powerwall
• Enphase
• Franklin
• Fortress
• and more!

Round-Trip Efficiency

The term round-trip efficiency refers to the amount of energy that can be stored and retrieved from a battery. It is an important factor to consider when choosing a battery for a specific application.

Round-trip efficiency is expressed as a percentage, with higher values indicating more efficient batteries. For example, if a battery has a round-trip efficiency of 80%, it means that for every 100 units of energy stored, only 80 units can be retrieved.

Factors such as internal resistance and charging/discharging rates can affect the round-trip efficiency of a battery. Therefore, it is essential to understand these factors and choose a battery with high round-trip efficiency for optimal performance.

As you can see, there are several key factors involved in choosing the ideal solar battery backup for your system. At Intermountain Wind & Solar, we have a team of experts who can help you navigate through these factors and find the best solar battery backup solution for your specific needs. Contact us today for any of our solar power services around SLC, Utah and Boise, Idaho areas!