What kind of energy might be saved up for future use?

 Energy cannot be created or destroyed, but it can be saved in various forms.
The term that denotes  the capture of energy produced at one time for use at a later time is energy storage.
Thermal energy might be saved up for future use.
Thermal storage is used for electricity generation by using power from the sun, even when the sun is not shining

Mitochondria is the cell organelle that produced the energy that is needed in the body system in form of atp, that is why it is called the power house of the cell. energy is needed by the living organisms to carry out the activities which sustain life.  if the mitochondria is destroyed atp will not be produced. if the mitochondria is destroyed, energy production will stop and the affected living organism will not have the energy to carry out the necessary life processes; this will lead to the death of the organism.