Solar Battery Systems – RiwaSun Consultants Limited

What is battery storage?

Batteries are by far the most common way for residential installations to store solar energy. When solar energy is pumped into a battery, a chemical reaction among the battery components stores the solar energy. The reaction is reversed when the battery is discharged, allowing current to exit the battery. Lithium-ion batteries are most commonly used in solar applications, and new battery technology is expanding rapidly, which promises to yield cheaper, more scalable battery storage solutions. In fact, U.S. energy storage is expected to reach nearly 7.5 GW annually by 2025, a sixfold growth from 2020, representing a market worth $7.3 billion

Comparing Battery Storage Technologies

Lithium-Ion battery

As mentioned earlier, battery manufacturers prefer lithium-ion battery technology for its higher DoD, reliable lifespan, ability to hold more energy for longer, and a more compact size. However, because of these numerous benefits, lithium-ion batteries are also more expensive compared to lead-acid batteries.

Lead-Acid battery

Lead-acid batteries (the same technology as most car batteries) have been around for years, and have been used widely as in-home energy storage systems for off-grid power options. While they are still on the market at pocket-friendly prices, their popularity is fading due to low DoD and shorter lifespan.

Types of solar batteries

Lead-acid

One of the oldest and most affordable types of solar batteries, but have a shorter lifespan and higher maintenance costs.

Lithium-ion

More expensive than lead-acid, but have a longer lifespan and are more efficient.

Flow

Use a liquid electrolyte that is pumped through the battery.

Gel

Considered safe to use because they do not contain any liquid electrolyte.

The Science of Solar Batteries

Lithium-ion batteries are the most popular form of solar batteries on the market. This is the same technology used for smartphones and other high-tech batteries.

Lithium-ion batteries work through a chemical reaction that stores chemical energy before converting it to electrical energy. The reaction occurs when lithium ions release free electrons, and those electrons flow from the negatively-charged anode to the positively-charged cathode.

When you draw electricity from the battery, the lithium ions flow back across the electrolyte to the positive electrode. At the same time, electrons move from the negative electrode to the positive electrode via the outer circuit, powering the plugged-in device.

Home solar power storage batteries combine multiple ion battery cells with sophisticated electronics that regulate the performance and safety of the whole solar battery system. Thus, solar batteries function as rechargeable batteries that use the power of the sun as the initial input that kickstarts the whole process of creating an electrical current.

How Solar Batteries Work with a Solar Power System

This entire process starts with the solar panels on the roof generating power. Here is a step-by-step breakdown of what happens with a DC-coupled system:

Sunlight hits the solar panels and the energy is converted to DC electricity.
The electricity enters the battery and is stored as DC electricity.
The DC electricity then leaves the battery and enters an inverter to be converted into AC electricity the home or the grid can use.

The process is slightly different with an AC-coupled system.

Sunlight hits the solar panels and the energy is converted to DC electricity.
The electricity enters the inverter to be converted into AC electricity the home can use.
Excess electricity then flows through another inverter to change back into DC electricity that can be stored for later.
If the house needs to use the energy stored in the battery, that electricity must flow through the inverter again to become AC electricity.