Solar energy is a clean and renewable source of energy that can be harnessed to power homes, businesses, and communities. One of the key challenges in utilizing solar energy is figuring out how to store it for use when the sun isn’t shining.
Most homeowners choose to store their solar energy using a battery. Today, most solar energy is stored in lithium-ion, lead-acid, and flow batteries.
Technically, you can store solar energy through mechanical or thermal energy storage such as pumped hydro systems or molten salt energy storage technologies, but these storage options require a lot of space, materials, and moving parts. Overall, not the most practical way to store energy for a home.
There are a few different ways that solar energy can be stored, including:
Battery storage
Batteries are used to store solar energy generated by residential solar panels. When the solar panels produce electricity, it is directed into the battery where a chemical reaction occurs, storing the energy. When the stored energy is needed, the chemical reaction is reversed, allowing the stored electricity to flow out of the battery and into the home.
There are a variety of different types of batteries that can be used for this purpose, including lead-acid batteries, lithium-ion batteries, and flow batteries.
Lithium-ion batteries are the most commonly used type of battery in solar applications because they have a high energy density and long lifespan. However, new battery technologies are being developed that promise to be cheaper and more scalable, and these are expected to drive growth in the energy storage market.
The U.S. energy storage market is forecast to reach 7.5 GW annually by 2025, which represents a sixfold growth from 2020, and a market worth $7.3 billion.
Thermal storage
Another way to store solar energy is by using thermal storage systems. These systems use the heat generated by solar panels to heat a fluid, such as water or molten salt.
The heat can then be stored in a thermal storage tank and used later to generate electricity through a steam turbine or other heat-to-power conversion technology.
Pumped Hydro Storage
Pumped hydro storage is another way to store solar energy. It involves pumping water from a lower reservoir to an upper reservoir using excess solar or wind energy. When the energy is needed, the water is released back to the lower reservoir through a turbine, generating electricity.
Compressed Air Energy Storage (CAES)
Compressed air energy storage (CAES) is a method that uses surplus electricity to compress air and store it in large vessels such as a tank or underground formation. The compressed air can then be released to generate electricity during peak demand times by flowing through a turbine.
This method is relatively fast, and efficient and can provide quick energy during peak demand times. However, it is less common than the other methods due to the high costs and technical challenges associated with it.
Flywheels
Flywheel energy storage is a method that uses surplus electricity to spin a large, heavy wheel (the flywheel) at high speeds. The flywheel acts as a kinetic energy storage device, storing the surplus energy in the form of rotational energy.
When the demand for electricity is high, the flywheel can be used to generate electricity by slowing down and releasing the stored energy through an electric generator. This method is relatively fast, and efficient and can provide quick energy during peak demand times.
Each of these methods has its own advantages and disadvantages, and the best storage solution will depend on factors such as cost, location, and the specific needs of the user. As technology continues to advance, new and more efficient ways of storing solar energy are likely to be developed.
More: What is Solar Energy?
