Question

energy can neither be created nor destroyed in this context of the statement explain why do we talk about energy crisis

Answer 1

Energy sources vary in quality, and EXERGY is a name for the useful fraction of an energy source.  This fraction approaches 100% for electricity and light, and approaches zero for a heat source just barely above the ambient temperature.  Exergy can be destroyed, and when we "waste" energy, we are allowing exergy to be destroyed unnecessarily.