Lämpökylmäenergia

Lämpökylmäenergia, also known as thermochemical energy storage, is a method of storing thermal energy by using reversible chemical reactions. Unlike sensible heat storage, which stores heat by changing the temperature of a material, or latent heat storage, which stores heat by changing the phase of a material, thermochemical energy storage utilizes the energy released or absorbed during a chemical reaction.

The principle behind thermochemical energy storage involves two chemical species that can react with each other in an endothermic (heat-absorbing) process and then be separated. Later, when heat is needed, the separated species can be recombined in an exothermic (heat-releasing) reaction, releasing the stored thermal energy. This process is often cyclical.

A common example involves the reaction between hydrated salts and water. When heat is applied, water is driven off from the salt, creating an anhydrous salt and water vapor. This process stores energy in the chemical bonds of the anhydrous salt. When the anhydrous salt is later exposed to water vapor, it rehydrates, releasing the stored heat.

Thermochemical energy storage offers several advantages, including high energy density, long-term storage capabilities with minimal heat loss, and the ability to store heat at high temperatures. This makes it a promising technology for various applications, such as solar thermal energy utilization, industrial waste heat recovery, and building heating and cooling systems. However, challenges remain in terms of cost-effectiveness, material stability, and system complexity.