Since the days of the early Greeks, Romans, and Chinese, when, archaeologists believe, ice and snow was stored in caves for use during warm weather,1 man has been practicing thermal-energy storage (TES).
TES is achieved through two mechanisms: sensible-energy storage and latent-energy storage. Sensible-energy storage is accomplished by decreasing the temperature of the stored medium. Latent-energy storage is accomplished by changing the phase of the stored medium. F