Solar Energy Storage & Solar Battery System
Solar Energy Storage
Even the most enthusiastic solar evangelist will agree with one limitation of solar panels: They only generate electricity when the sun is shining. However, energy usage peaks often occur at night, which coincides with the reduction in solar power generation and leading to supply and demand problems. The problem is that during sunny low-demand periods, solar panels usually output enough energy to meet the peak demand later in the day. This means that efficient solar storage can open up a lot of possibilities for homeowners and businesses alike.
What is solar battery storage?
Solar energy can also be stored in electrochemical cells. When solar energy is pumped into the battery, the chemical reactions between the battery components store energy. When the battery is discharged, the reaction is reversed, allowing current to flow out of the battery. Lithium-ion batteries are most commonly used in solar applications, and new battery technologies are developing rapidly and are expected to provide cheaper and more scalable battery storage solutions. In fact, by 2025, the US’s energy storage capacity is expected to reach nearly 7.5 gigawatts per year, an increase of six times over 2020, and the market value is 7.3 billion US dollars.
Different types of energy storage can be divided into five major technical categories:
Within these scopes, they can be further subdivided into utility-scale or batch systems, customer sites, and residences in terms of application scale. In addition, with the electrification of transportation, there is a further category of mobile applications.
1. Battery storage
The battery is the oldest, most common and widely used form of storage. It is an electrochemical technology that consists of one or more batteries with positive terminals, called cathodes, negative terminals or anodes.
The battery contains a series of chemical components. The most widely known and widely used in portable electronic devices and vehicles are lithium ion and lead acid. Other solid battery types are nickel-cadmium and sodium-sulfur, while zinc-air is emerging.
The other is a flow battery with a liquid electrolyte solution, including vanadium redox and iron chromium and zinc bromide chemistry.
Although supercapacitors are not batteries, they can also be classified as electrochemical technologies, and their applications are especially suitable for sub-minute response.
2. Mechanical storage
The mechanical storage system can be said to be the simplest. It uses the kinetic energy of rotation or gravity to store energy. But the feasibility of today’s grid applications requires the application of the latest technology.
The main option is energy storage with a flywheel and compressed air system, and gravity energy is an emerging technology, and various options are being developed.
3. Thermal storage
Thermal storage essentially involves capturing and releasing heat or cold in solids, liquids or air, and may involve changes in the state of the storage medium, such as from gas to liquid or from solid to liquid, and vice versa.
Technologies include the use of molten salt and liquid air for energy storage or cryogenic storage. Molten salt has become commercially viable with concentrated solar energy, but this and other heat storage options may be limited by the demand for large underground storage caves.
Hydrogen energy storage is still emerging, and it involves the conversion of electrical energy through electrolysis into storage tanks. Afterwards, it can be re-electrified or supplied to emerging applications, such as transportation, industry or residential, as a supplement or substitute for natural gas.
5. Pumped storage
For most of the past century, pumped storage systems based on large reservoirs have been widely implemented, becoming the most common form of utility-scale energy storage in the world.
Such a system needs to circulate water between two reservoirs at different levels, and “store energy” in the water of the upper reservoir. When the water is released to the lower reservoir, the energy will be released.