How to choose the best battery for a solar energy system
Each year, it’s becoming more common to install solar batteries with solar panels. They provide significant benefits, such as energy independence and emergency backup power, but it can be difficult to know exactly what to look for when shopping for a solar battery.
Solar batteries are used to store energy that solar panels produce. The stored solar energy can then be used later on, when it is needed.
Solar panels make more electricity during the middle of the day than they do at any other time of day. The middle of the day also happens to be when your home uses the least amount of energy. Because of this, your solar panels will produce a lot of electricity that your home won’t need at that time.
Solar batteries are able to store that extra energy from the middle of the day so you can use it at a different time.
What are the benefits of solar battery storage?
A solar battery could be a great investment for your home, depending on what you want to get out of your battery storage system. There are a few reasons why you might want to install a solar battery.
Less dependence on the grid
For one, solar batteries allow you to be less dependent on the grid. Having great energy independence also means that you have the ability to power your home entirely with clean solar energy.
Producing clean energy
Utilities derive the majority of their electricity from dirty fossil fuels. Installing a solar battery ensures that you will power your home entirely with renewable energy produced right on your roof!
Access to backup power
The utility grid can be unreliable. Solar batteries can be used as a backup power source when the grid goes down. It is especially useful to have a backup battery bank in places like California, where grid outages are common during wildfire season.
Big savings on your electric bill
Solar batteries also have the potential to save you money on your electric bill. This is especially true if your utility uses a time-of-use rate structure. This means that your utility will charge different rates for electricity depending on what time of day it is. Solar batteries can also offer bill savings if your utility does not offer full retail net metering.
What features to look for when shopping for solar battery storage
There are 4 key features to consider when looking to buy a solar battery: the power and capacity ratings, the depth of discharge, the efficiency rating, and the warranty.
Let’s take a closer look at each of these terms and what they mean.
1. Power and capacity ratings
The first thing you need to look at when purchasing solar battery storage is its capacity rating and the power rating. The capacity rating tells you how many kilowatt-hours (kWh) of electricity a solar battery can hold.
You can install multiple batteries to increase the capacity of your solar storage system. It represents the actual supply of (or how much) electricity you have stored in your battery.
The capacity rating isn’t very useful on its own. You also have to consider the power rating of a battery. The power rating tells you how much electricity a battery can deliver to your home at one time, measured in kilowatts. This will give you an idea of how many appliances you can power in your home with a solar battery.
If a battery has a high capacity, but a low power rating, it will be able to power a few important appliances, like a refrigerator and an electric water heater, for a prolonged period of time. These types of batteries are useful if you are looking to use your battery as an emergency backup generator.
A battery with a low capacity and a high power-rating will be able to power the whole house, but only for a few hours because there are fewer kWhs stored in the battery.
2. Depth of discharge (DoD)
The depth of discharge (DoD) of a solar battery is the percentage that a battery has been discharged relative to the total capacity of the battery. Most solar batteries will have a specific DoD listed to maintain the health of the battery.
For example, let’s say you have a solar battery with a 10 kWh capacity with a recommended DOD of 60%, you shouldn’t use more than 6 kWh of electricity before you recharge it. Using any more than 6 kWh could damage the battery.