What Is the Best Battery for Storing Solar Energy?

10 Jan 2018

Solar energy is a great form of renewable energy, and for that reason, it has been growing rapidly in popularity! However, while the solar panels you use will harness the sun’s rays and transform them into a useable form of energy, it’s still necessary to store that energy until you are ready to use it.

Choosing the right battery for your needs can be a little tricky. To help you make sure you are getting the best possible battery to store your solar energy, here’s everything you need to know:

What You Should Look for in a Battery

There are a number of specifics you should consider when evaluating your options for a solar battery. One includes how long this solar battery will last you. In addition, you want to take into account how much power it will be able to provide.

As you consider converting to solar and choosing your storage options, you will likely encounter a lot of complicated specifications that make little to no sense to you (unless you are well-versed in solar terminology). The most important ones you’ll need to understand during your search are the capacity and power ratings, depths of discharge (or DoD for short), warranty, round-trip efficiency, and manufacturer.

Let’s break them down one by one so you can understand the terms being used and be able to make effective comparisons when looking around for the best solar battery.

Capacity and Power

Capacity is a term that refers to the total electricity amount that the solar battery can hold, measured in kilowatt-hours, or kWh. Most home solar batteries are made to have a stackable quality. This means that multiple batteries can be used in a solar-plus-storage system, allowing increased capacity.

While capacity refers to how big a battery it, it doesn’t include how much electricity it is able to provide at one time. This is where the power rating comes in. This is the amount of electricity a battery can delivery at once, and it is measured in kilowatts, or kW.

In short, a battery with a low power rating and high capacity can deliver a small amount of electricity for a long time. A battery with a high power-rating and low capacity can run your entire home, but for just a few hours.

Depth of Discharge

Because of their chemical composition, most solar batteries are required to retain some amount of charge constantly. If you use the battery’s entire charge, the time that it is useful will be shortened substantially.

The depth of discharge of a battery refers to how much the capacity has been used. Most manufacturers specify a battery’s maximum DoD for best performance. If a 10-kWh battery comes with a 90% DoD, you shouldn’t use over 9 kWh of battery before it is recharged. In general, the higher a DoD, the more battery capacity you can use.

Round-Trip Efficiency

The round-trip efficiency of a battery refers to how much energy can be used as a percentage of how much energy it takes to store it. Here’s an example: You feed 5 kWh of electricity but can only use 4 kWh of it. That means your battery has round-trip efficiency of 80%. Higher round-trip efficiency allows more economic value from your battery.

Battery Life and Warranty

These are words you’re probably more familiar with hearing. In terms of solar batteries, battery life refers to its ability to hold a charge – much like your cell phone.

In addition, your solar battery likely comes with a warranty to guarantee a specific number of cycles of using this battery life, as well as years of useful life. Battery performance, over time, tends to naturally degrade. For this reason, most manufacturers guarantee that their battery will maintain a certain capacity over the time of its warranty.

So, if you are in search of a solar battery that will last a long time, this will depend on the battery life and warranty.

Manufacturer

It only makes sense that the battery you purchase will only be as good as the manufacturer that produced it. Like you would with any other large purchase, if you are trying to buy a high-quality battery, make sure that it comes from a trusted manufacturer that produces good products.

The Verdict

The solar battery you choose to purchase is a big deal, and will hopefully last you for years to come! Make sure you make the right decision for you, your home, and your energy needs.

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