> Water does not have the capability to store much energy. Systems that make ice at night and use it for A/C during the day date back to the 1950s. The genera

> Water does not have the capability to store much energy. Systems that make ice at night and use it for A/C during the day date back to the 1950s. The general class of these facilities is phase-change materials. Water is pretty amazing, both for ice and for steam.