Ilmapainevarastot

Ilmapainevarastot, also known as compressed air energy storage (CAES), are systems designed to store mechanical energy in the form of compressed air. These systems typically involve a compressor, a storage vessel, and a turbine. During periods of low energy demand or when renewable energy is abundant, surplus electricity is used to drive a compressor, which forces air into a storage vessel. This vessel can be an underground cavern, an above-ground tank, or even a depleted gas field. When energy is needed, the compressed air is released, often heated, and then expanded through a turbine to generate electricity.

There are two main types of CAES: diabatic and adiabatic. Diabatic systems reheat the air using external fuel, usually natural gas, before it enters the turbine, which increases efficiency but also produces emissions. Adiabatic systems aim to store the heat generated during compression and use it to reheat the air during expansion, thereby avoiding the need for external fuel and achieving near-zero emissions. However, maintaining the stored heat efficiently remains a significant technological challenge for adiabatic CAES.

CAES technology offers several advantages, including long-duration energy storage capabilities, which are crucial for grid stability and integrating intermittent renewable sources like solar and wind power. It can also provide grid services such as frequency regulation and load shifting. However, challenges include high initial capital costs, geographical limitations for underground storage, and the energy conversion losses inherent in the compression and expansion process.