Battery for Solar System

Going solar for your RV, lodge, home, or anywhere else is a good way to commit to environmental conservation by minimizing your footprint. However, it is not an all-in-one system and you need to collect various components for the solar system to work properly. Your commercial or solar energy system will require a battery bank, which is why you must choose the best battery for solar system. 

Without a functional battery backup, your solar panel system is no longer reliable. It can produce energy, but there’s no solar energy storage option for overnight use. Besides, you have no backup power for when you are off-the-grid.

Home energy storage batteries have been around for a long time, with numerous sizes and varieties now available in the market. Due to the technological advancements in lithium tech, modern lithium-ion batteries have superseded lead-acid batteries as manufacturers continue to develop smart modular systems that suit various energy storage applications. The sheer number of home storage battery systems is great for consumers. Still, it is also challenging to choose the best battery storage systems for commercial and residential solar systems. 

How do solar energy batteries work?

Battery for Solar System

Installing solar batteries as part of your commercial or residential solar panel system makes it possible to store excess solar energy rather than sending it back to the power grid. Suppose your solar paneling is producing more electrical power than you need. In that case, this energy can go into charging your batteries. 

When the solar panel system isn’t producing electricity, you can draw energy from the battery backup whenever needed. The excess electricity will be sent back to the grid only when your home battery storage system is full. Similarly, you will draw power from the grid only when your batteries are low.

What are the types of solar batteries?

Home battery storage systems are typically made of lithium-ion or lead-acid. When choosing the best battery for solar system, it is essential to know the different solar battery technologies such as the flooded lead-acid battery, deep cycle batteries, sealed lead-acid battery, and lithium-ion battery.

1. Lithium-ion battery

The lithium-ion battery is the most recent battery storage technology that hit the market in the early 1970s. These batteries are common in cell phones and laptops, but lately, they have made their way into the renewable energy industry. Lithium-ion batteries are expensive, but there are several advantages to justify the high price tag. 

  • Require no maintenance
  • They have a longer life span compared to other types of batteries
  • They are associated with efficient power storage
  • They have more usable storage capacities, often referred to as deeper discharges
  • No ventilation or off-gassing is necessary

According to a recent report from the United States Solar Energy Monitor, lithium-ion batteries are the most common energy storage technology, no matter the type of application. Generally, there are three types of lithium-ion batteries. Pouches are often installed in tablets and smartphones, while cylindrical lithium-ion batteries are often installed in various power tools. Lastly, prismatic lithium-ion batteries (come in different shapes) are installed in electronic vehicles and other similar appliances.

Note that prismatic lithium-ion batteries have corrugated sides, creating gaps between the adjacent cells to aid in cooling. These batteries are also commonly used in solar energy storage, particularly lithium-ion phosphate (LFP) batteries.

2. Flooded lead-acid batteries

These batteries have been around for the past 150 years and are still being used for off-grid solar setups. They are 99% recyclable, inexpensive, and easy to dispose of if no longer functional. Most renewable energy experts agree that flooded lead-acid batteries are best for solar energy storage, particularly if you’re looking for a more affordable option. However, it would help if you keep the following in mind; 

  • FLA batteries are designed to handle charge cycling daily. They require proper ventilation because they emit gas as a byproduct.
    • They are ideal for consumers who prefer to be hands-on with their battery for solar system.
  • They are an affordable option but require occasional maintenance to keep them functional.

The plates of each cell in the battery should be submerged in water to function properly, which is why they are referred to as flooded batteries. You will need to add the recommended amount of water every 1-3 months to keep the plates submerged. 

3. Sealed lead-acid batteries

Suppose you don’t have the time to perform timely battery checkups; the best battery for solar system is the sealed lead-acid option. These batteries are non-hazardous and spill-proof. They’re some kind of a self-contained power storage system. So, you don’t need to refill them with water. This is why sealed lead-acid batteries work at homes and commercial properties that are not occupied full-time. So if you have an off-grid cabin that you visit several times a year, sealed lead-acid batteries may be good for you. 

These batteries are also better at handling various temperature levels. Besides, they will not discharge fast, even when they sit idle for a long time. 

If you are unsure of the specific type of battery that is good for your home, consult with the solar energy experts at Clear Sky Solar

Choose the best battery for solar system.

Battery for Solar System

There are essential specifications that you must compare when evaluating various solar battery options. Some of these technical specifications include depth of discharge (DoD), power ratings, capacity, warranty, round-trip efficiency, and more. 

1. Battery capacity & power ratings

Capacity is simply the total amount of electricity (measured in kilowatt-hour) a battery can store. Many residential solar batteries are specifically designed to be “stackable.” That means you can add several solar batteries to a solar-plus-storage system to generate extra capacity. 

Though capacity indicates how big a battery is, it does not indicate how much electricity a battery can offer at a given moment. It would help if you considered the unit’s power rating to get the complete picture of how much electric energy the unit can provide. 

Batteries with a low power rating and high capacity deliver a low amount of electric power (sufficient to run a few appliances) for an extended period. On the other hand, batteries with a high power rating and low capacity can run the entire home but for a short period. To choose the best battery for solar system, consult with Clear Sky Solar. We will help you determine how much electric power your residential solar system generates, how much energy your home needs, and determine the most efficient residential energy storage option. 

2. Depth of discharge 

Solar batteries must retain a certain level of charge at all times because of their chemical composition. Using 100% of your battery’s charge may shorten its useful life significantly. A battery’s depth of discharge refers to the level of its capacity that has been used. Many manufacturers specify the maximum depth of discharge for optimal battery performance. 

Suppose a 10 kilowatt-hour (kWh) battery has a depth of discharge of 90%. In that case, you should not use over 9 kWh of the battery before you recharge it. Generally, batteries with a high depth of charge allow consumers to use more of the battery’s capacity. 

3. Battery’s life and warranty

For many uses of residential energy storage, your batteries will ‘cycle’ (drain and charge) daily. The unit’s ability to hold charge will decrease gradually as you continue to use the unit. That means a battery for solar system are like cell phone’s batteries. Just think about it; you charge your smartphone nearly every night to use it the following day. As the device gets older, you will notice that its battery isn’t retaining as much charge as it did previously. 

For instance, a battery for solar system may come with a warranty of for 5,000 cycles or ten years at 70% of the original storage capacity (10-year warranty). That means at the end of the warranty, the power storage unit will have lost about 30% of its original capacity. 

A reliable choice of solar batteries must have a warranty that guarantees a specific number of useful years or cycles. The battery storage performance degrades naturally over a given time period, which is why many manufacturers guarantee that the unit will retain a specific amount of its capacity over a given time. So, how long will your solar battery last? The answer depends on the battery types you prefer, brand, and the amount of capacity the unit will lose over time. 

4. Round-trip efficiency 

Your battery’s round-trip efficiency refers to the amount of electrical energy available for use as a percentage of the total energy it took to store it. Suppose you feed 5 kWh of electrical power into your energy storage unit and get 4 kWh of useful electric energy. In that case, your unit has 80% round-trip efficiency. 

Lithium-ion or lead-acid batteries with high round-trip efficiency offer more economic value, making such batteries a worthwhile investment for residential and commercial property owners. 

5. Manufacturer 

There are different types of organizations developing and manufacturing solar panels and batteries for solar systems. These organizations range from tech start-ups to established automotive corporations. It is essential to check the product manufacturer’s reputation, the quality of solar panels or batteries on offer, and customer service quality before you purchase. It’s also in your best interest to evaluate the warranties linked to each product. 

How long do solar energy batteries last?

Battery for Solar System

This question can be answered in two ways. First, you need to evaluate how long the battery for solar system can power your property. A fully-charged unit can run your household overnight when solar panels aren’t generating energy. To get more reliable estimates, you must understand a few variables. These include the amount of electric energy your home uses daily, the power rating & capacity of your residential energy storage unit, and whether you’re connected to the power grid. 

To help you understand how long your battery for solar system can last, check this illustration. We will determine the size of the battery required to provide sufficient solar plus storage solution in accordance with the data from the United States Energy Information Administration. Suppose an average United States home uses 30 kWh of electric energy daily, and a solar energy storage unit can provide 10 kWh of capacity. In that case, that household needs three batteries to run the entire household. 

But the exact answer is more complex than that. Your solar panels will be generating power during the day (6-7 hours). Besides, many types of batteries can’t operate at maximum capacity and often peak at 90 percent DoD. That means a 10 kWh battery has a useful capacity of about 9kWh. 

Ultimately, if you’re pairing your batteries with a solar PV array, you need one or two batteries to power your household during the night when the solar panels aren’t generating energy. But you need three or more batteries to power the entire home for 24 hours. 

The second way of determining how long solar batteries last involves analyzing the lifespan of these energy storage units. Many solar companies that handle solar installations unanimously agree that a solar battery lifespan ranges from 5years to 15 years. Suppose you install a battery for solar system today; you’ll likely need to replace it once to match the 25-year to 30-year lifespan of most solar energy systems. Note that proper maintenance has a direct impact on the battery’s lifespan. 

Should I install battery for solar system?

Solar battery technology has been around for a very long time, but the energy storage units used in residential solar-plus-storage- systems are new to the market. Here are the benefits of installing a battery for solar system. 

Dependable emergency energy: Extremely hot summers and harsh winter storms strain power grid systems. Similarly, massive tornadoes and severe hurricanes can create disastrous scenarios that most Americans are not prepared for. A high-quality battery for solar system will provide backup power during grid failures. 

Minimal maintenance: Solar batteries use a widely-available and free source of fuel. They don’t depend on gas and other in-demand commodities. Depending on the high-power battery type you install, you will need to check on the unit once in a while. 

Now you know…

Though the price of solar batteries is high, the benefits of installing energy storage batteries outweigh the cost. If you are planning to switch to solar energy and have safety concerns, contact the solar panel installation experts at Clear Sky Solar. We will help you choose high efficiency batteries, inverters, and handle the installation process of a solar system that will address your household’s energy demands.