Guide to Solar Batteries: Are They Worth It? (August 2024)

All solar batteries have the same basic function, but each type is suited for different applications. Your solar battery will offer higher reliability and return on investment when its chemistry is suitable for the application at hand. In general, lithium-ion batteries are most commonly used for residential solar systems due to their high efficiency and compact size when compared with other battery types.

Please visit our website for more information on this topic.

Lithium-Ion

Lithium-ion batteries have become very popular in recent years since they can achieve synergy with solar panels and wind turbines. For example, the Tesla Powerwall and Enphase IQ are two types of lithium-ion batteries commonly used in home solar applications. You can also find smaller lithium batteries from brands like Renogy and WindyNation, which are portable and better suited for DIY solar projects.

Lithium iron phosphate or LFP batteries are a subtype of lithium batteries, characterized by a superior service life. The best LFP batteries offer a service life of over 4,000 cycles at 80% DoD, which means they can last for over 10 years on a daily charging cycle. This makes LFP batteries the ideal complement to solar installations. Unlike lead-acid batteries, which need separate charge controllers, many of the lithium battery models that are commercially available come with built-in chargers and controls.

The main drawback of lithium-ion batteries is the high price, but this could change in the near future &#; the U.S. Department of Energy is targeting a 90% energy storage cost reduction by . Lithium batteries can also suffer a phenomenon called thermal runaway when used at high temperatures, which causes them to catch fire. You can prevent thermal runaway by making sure your batteries are high-quality and installed by qualified electricians.

Lead-Acid

Lead-acid batteries are an established technology, commonly used by off-grid solar energy systems in remote locations. Lead-acid batteries are affordable and have a well-established supply chain due to their popularity, so you can easily find vendors and technical support.

In spite of their low cost, lead-acid batteries have some technical limitations you should consider:

• Lead-acid batteries typically have a charging life of 500 to cycles.
• Batteries should be fully recharged after each use, or the lifespan is drastically reduced.

An absorbed glass mat or AGM battery is an improved version of the traditional lead-acid battery. They can charge faster while having a spill-proof design and more durability. You can also find AGM deep cycle batteries that are designed for 80% DoD.

Using lead-acid batteries along with solar panels requires charge controllers to sustain a suitable charging current. These batteries should not be wired directly to your solar array, or your system may be damaged by excessive current.

Nickel-Cadmium

Nickel-cadmium batteries are characterized by their durability, tolerance to high temperatures and simple maintenance needs. Thanks to these performance features, nickel-cadmium batteries are popular in industrial and utility applications. Unfortunately, cadmium is highly toxic to humans, so nickel-cadmium batteries are not recommended in homes.

Goto SUNJ ENERGY to know more.

Flow

Flow batteries store energy by separating positive and negative electrical charges in chemical solutions, which are stored in separate tanks. When these two solutions interact, they undergo a reduction-oxidation reaction (redox) and the battery releases energy. This battery technology is also referred to as &#;redox flow&#; for this reason.

The main disadvantage of redox flow batteries is their space requirement, and they are not cost-effective for small-scale projects. Even a small redox flow battery system can be the size of a shipping container, so using flow batteries in home solar systems is not viable.

How much battery storage you need

If you just want to back up a few critical loads, your solar battery cost will be on the lower end. If you're looking to back up your whole home or go off-grid, expect to pay a lot for battery storage. We're talking $20,000 to over $80,000 in some cases.  

Compared to solar panel systems, batteries are a bit less customizable in terms of size. It's usually pretty easy to add or subtract a single solar panel to get the ideal system size. It's more challenging to fine-tune the size of the battery, though this is improving. Some companies today offer very modular options for more flexible configurations. 

Your battery's inverter

Batteries store direct current (DC) electricity, but your appliances use alternating current (AC) electricity. You need an inverter to convert the DC electricity stored in your battery to usable AC electricity. Some batteries come with a hybrid inverter that also works with solar or a storage-specific inverter. If yours doesn't, you'll need to purchase one separately. The inverter could add a couple thousand dollars to your system cost. 

If you already have solar or not

Energy storage installations require significant electrical work. If you install storage at the same time as your solar system, you save money by getting the electrical work completed simultaneously. If you retrofit a battery to an existing solar system, you'll pay extra for labor, wiring, and in some cases, equipment.

If you need to upgrade or add a new electrical panel

As we said, big storage projects cost a lot of money. Most home battery systems today aren't large enough to cover all your electricity usage. This means you need to put specific circuits onto a critical load panel. A critical load panel functions like a secondary electrical panel. On the panel, you include the essential circuits that you want to remain energized in the event of an outage. 

While the critical load panel itself isn't costly, the electrical work required to install one can add up. Some battery companies today offer load management devices that make critical load panels unnecessary. If you have or choose to install a smart electrical panel, you also won't need a separate critical load panel for your battery.

Are you interested in learning more about battery storage solutions? Contact us today to secure an expert consultation!