Ultra-dense energy storage utilizing high melting point metallic alloys and photovoltaic cells

A novel concept for energy storage utilizing high melting point metallic alloys and photovoltaic cells is presented. In the proposed system, the energy is stored in the form of latent heat of metallic alloys and converted to electricity upon demand by infrared sensitive photovoltaic cells. Silicon is considered in this paper due to its extremely high latent heat (1800 J/g), melting point (1410°C), low cost (~$1.7/kg) and abundance on earth. The proposed solution enables an enormous energy storage density of ~ 500 Wh/kg and ~ 1 MWh/m³, which is 12 times higher than that of lead-acid batteries, 4 times than that of Li-ion batteries and 10 to 20 times than that of the molten salts utilized in CSP systems.