Energy can be transferred from one store to another:

i) Mechanically (by a force acting over a distance)
Eg: a car moving up an inclined plane
      (chemical potential energy –> gravitational potential energy)

ii) Electrically (by an electric current)
Eg: lighting up a bulb in an electric circuit
(chemical potential energy of battery –> light and heat energy of light bulb)

iii) By heating (due to a temperature difference)
Eg: a gas stove heating up a pot of water
(chemical potential energy of gas –> internal energy of water)

iv) By propagation of waves (both electromagnetic and mechanical)
Eg: a dipper producing surface water waves
(mechanical energy of dipper –> kinetic energy of water waves)