Streaming potential is one of the four major electrokinetic phenomena where the flow of aqueous electrolytes due to an applied axial pressure gradient causes the generation of an induced axial electric field. The field may be evaluated by considerations of a net zero current due to the absence of an applied axial electric field. We elaborate on the theoretical aspects of streaming potential from fundamental considerations of electrostatics and fluid mechanics. Later, we focus on an exciting and futuristic application of streaming potential, where the induced electric field is tapped to drive a current through an external resistor thereby allowing one to convert mechanical energy into electrical energy.