Solutions:

During the conversion of energy from one form to another,

a portion of it is changed to an undesired form or lost to the environment as a result of friction or radiations, and this energy cannot be employed for productive purposes.

This is referred to as energy degradation or degeneration.

For instance, when a light bulb glows,

a large portion of the electrical energy used is transformed to heat energy, while a smaller portion is converted to useable light energy.