Patent ID: 8192633

Claim:
A method for energy storage and transfer using the phase change energy of sodium sulfate and sodium sulfate decahydrate, comprising, in combination, the steps of: (a) separating a sodium sulfate product from water containing sodium sulfate dissolved therein and contaminate salts other than sodium sulfate, said sodium sulfate product containing sodium sulfate and the contaminate salts other than sodium sulfate, wherein the phase change temperature of the sodium sulfate in said sodium sulfate product is adjusted to a preselected temperature by regulating the amount of said contaminate salts other than sodium sulfate in said sodium sulfate product; (b) storing energy in said sodium sulfate product by heating said sodium sulfate product to above said preselected temperature, producing a heated sodium sulfate product; and (c) transferring energy from said heated sodium sulfate product by cooling said heated sodium sulfate product to below said preselected temperature.