Question

Differentiate between energy conversion efficiency and energy end-use efficiency.

Answer 1

Energy conversion refers to the change of one energy form into another desired energy form such as from mechanical to electrical, electric to heat, etc. Energy conversion efficiency is the ratio of the the desired output energy form and the amount of input energy form. So basically it refers to how efficiently any energy is converted into some other form. In the conversion process not all amount of energy input can be converted, because some energy is lost in the process. That's why the converted output rages from 0-100% , though these two extremes are theoretical and conversion efficiency is between these two such as may be 60%, 70% etc.

Energy end use efficiency refers to the efficiency in desired work output which is received from any form of energy. So we can say it refers the efficiency in work done per each unit of energy. The more the work done per unit of energy, higher the end use efficiency. The end use efficiency is increased by technological interventions. For instance the incandascent electric bulb has lower end use efficiency than LED bulb, because the latter uses less amount of energy to do the same work of emitting visible light. The energy that is list as heat from incandascent bulb is not lost in LED bulb, so its ratio of work per energy is higher than incandascent bulb. So end use efficiency is higher.