Renewable Energy: Volume 2: Mechanical and Thermal Energy Storage Methods

Abstract

The present book reviews the possible methods of storing energy in the form of mechanical or thermal energy. The methods for mechanical energy storage that are reviewed include those that make use of gravitational potential energy, such as pumped hydroelectric energy storage and the potential energy associated with solid masses. The storage of energy by compressing air and the storage of energy as rotational energy in a flywheel are also described. The applications of these methods include grid storage and grid stabilization, as well as energy storage for transportation. There are three basic categories of thermal storage are (1) sensible heat of materials, (2) the latent heat of phase transitions and (3) the heat associated with chemical reactions. Sensible heat storage is discussed in terms of its application to residential heating, community-based heat storage, solar ponds, and thermal storage for grid-integrated energy systems. Latent heat storage may be used for both heating and cooling purposes and examples utilizing the solid-liquid transition of water and the liquid-gas transition of air are described. The basics of energy storage utilizing thermochemical reactions are presented.