The gradual decrease of useful energy due to radiation loss, friction, etc. is called degradation of energy.
Examples of degradation of energy —
- In transmission of electricity from a power generating station, a lot of electrical energy is wasted in the form of heat energy in the line wires used for transmission.
- When we cook food over a fire, the major part of heat energy obtained from the fuel is radiated out in the atmosphere. This radiated energy is of no use to us. It is thus a degraded form of energy.