What Are Solar Batteries and Solar Battery Types

What Are Solar Batteries

Without somewhere to send energy produced by your solar panels, solar would be fairly inefficient—your appliances would only work when the sun is shining and your panels are working. If you don’t use the energy, it’d be wasted—and you wouldn’t be able to use it at night. Enter solar batteries, which store energy generated by your panels for use when you actually need it. Solar batteries are an alternative (or addition to) feeding energy back to the grid and can help you make your house or facility somewhat immune from power outages and even help take it off-grid entirely.

How Do Solar Batteries Work?

Solar batteries hold the key to unlocking the full potential of renewable energy. As sunlight is converted into electricity by solar panels, any extra energy generated during sunny periods can be captured and stored within these batteries for future use. This also ensures a continuous power supply all year round.

Inside the solar battery, chemical reactions take place to store the surplus electricity as potential energy. So, when electricity is needed when the sun isn’t shining, such as during nighttime or overcast days, the stored energy is converted back into usable electricity and readily supplied to your home.

By allowing homeowners to maximize their solar energy consumption, solar batteries increase the reliability of solar power systems and decrease dependence on the conventional power grid. The ability to store and utilize solar energy even during periods of limited sunlight makes solar power a more practical and efficient choice for renewable energy.

Solar Battery Types

The four main types of batteries used in the world of solar power are lead-acid, lithium ion, nickel cadmium and flow batteries.

Lead-Acid

Lead-acid batteries have been in use for decades and are one of the most common types of battery used in automotive and industrial applications. They have a low energy density (meaning they cannot hold much energy per kg of weight), but remain both cost-effective and reliable and thus have become a common choice for use in a home solar setup.

Lead-acid batteries come in both flooded and sealed varieties and can be classified as either shallow cycle or deep cycle depending on the intended function and safe depth of discharge (DOD). Recent technological advancements have improved the lifespan of these batteries and lead-acid continues to be a viable option for many homeowners.

Lithium-Ion

The technology behind lithium-ion batteries is much newer than that of other battery types. Lithium-ion batteries have a high energy density and offer a smaller, lighter and more efficient option. They allow the user to access more of the energy stored within the battery before needing to be recharged, making them great for use in laptops and phones—and in your home.

The major drawback of lithium-ion batteries is the significantly higher cost to the consumer. If improperly installed lithium-ion batteries also have the potential to catch fire due to an effect called thermal runaway.

Nickel-Cadmium

Nickel-cadmium batteries are rarely used in residential settings and are most popular in airline and industrial applications due to their high durability and unique ability to function at extreme temperatures. Nickel-cadmium batteries also require relatively low amounts of maintenance when compared to other battery types.

Unfortunately, cadmium is a highly toxic element that, if not disposed of properly, can have a significant negative impact on our environment.

Flow

Flow batteries depend on chemical reactions. Energy is reproduced by liquid-containing electrolytes flowing between two chambers within the battery. Though flow batteries offer high efficiency, with a depth of discharge of 100%, they have a low energy density, meaning the tanks containing the electrolyte liquid must be quite large in order to store a significant amount of energy. This size makes them a costly and impractical option for most household use. Flow batteries are much better suited to larger spaces and applications.