What is energy degradation?

• the process by which energy becomes less available for doing work.
   

It's the principle that states that:

• water flows from a higher to a lower level.

• heat flows from a higher to a lower temperature.

• electric charge flows from a higher to a lower potential.

Examples of naturally occurring processes that illustrate the degradation of usable energy into internal energy:  

• Lightning - electric potential energy is discharged

• Wildfire - chemical potential energy is released via oxidation

• Waterfall - gravitational potential energy is released as water falls down a cliff