How to store solar energy for 18 years？

Chalmers University of Technology in Gothenburg, Sweden, has invented a solar cell that can store solar energy for 18 years. Details of the project have yet to be announced, but it is known to successfully store and release solar energy generated by thermoelectric generators.

Scientists believe that this is "a whole new way of solar power generation." This means that solar energy can generate electricity whether it is sunny or rainy or snowy. In addition, this means that solar energy storage technology has risen to a new level, because solar energy can be transported anywhere, at the same time, without compromising its quality and energy.

Thermal storage technology has been the focus of solar technologists for decades, because solar energy requires long-term storage capacity. Traditional battery storage requires energy conversion from solar energy. With heat storage technology, a heated container can hold molten substances (such as water or molten salt).

In the next decade or more, the development of solar technology at Chalmers University of Technology is expected to reach new heights.

How to store solar energy?

Solar energy storage can be divided into three categories, namely thermal energy storage, battery energy storage and mechanical energy storage.

What is thermal energy storage?

Thermal energy storage utilizes various media, such as water or molten salt, to absorb and retain heat from solar energy. This heat transfer medium is stored in an insulated container. When energy is needed, it can be obtained by boiling water.

What is battery energy storage?

Solar energy can also be stored in electrochemical cells. When solar energy is pumped into the battery, chemical reactions occur between the battery components, which store the energy. When energy is needed, this chemical reaction is reversed, releasing energy. Lithium-ion batteries are most commonly used for solar energy storage, and new battery technologies are developing rapidly, and it is expected that cheaper and more scalable battery storage solutions will be developed in the future. Data shows that by 2050, US energy storage is expected to reach nearly 7.5 million kilowatts per year (six times that of 2020), with a market value of $7.3 billion.

What is mechanical storage?

Mechanical storage technology uses the potential energy of objects to generate electricity. Mechanical storage can convert excess electrical energy into mechanical energy, and then convert mechanical energy into electrical energy when electrical energy is needed. There are three main mechanical energy storage systems:

Flywheel storage

This storage method uses excess power to drive a flywheel to rotate, uses the flywheel to generate electricity, and quickly provides energy during peak electricity consumption periods.

Pumped Hydroelectric Storage

Pumped hydro storage is the use of pumped hydro to pump water uphill into a reservoir located above a turbine generator. Water can flow through turbines to generate electricity during times of high demand for electricity.

Compressed air storage

Compressed air storage technology can pump compressed air into large containers, such as gas storage tanks or underground rock formations. During peak electricity consumption, the air can be released to generate electricity.

The best way to store solar energy

Currently, there is no perfect way to store solar energy. The choice of solar energy storage method depends on demand and available resources.

Commercial solar storage

Electric utilities and businesses have more budgets than individuals and households, so they can choose between mechanical storage and thermal energy storage. Although these storage methods are expensive, they allow power companies to provide sufficient power during peak demand.