What do you know about energy types? Find out in this KS3 Science quiz. Physicist Hermann von Helmholtz established that all forms of energy are equivalent - energy in one form can disappear but the same amount of energy will appear in another form. As one type of energy is transferred into another, it is often possible to make things happen.
An example of this is a hydroelectric power station. Water in a reservoir high in the mountains has more gravitational potential energy than when it is lower down. As it flows downhill, the gravitational potential energy is transformed into kinetic energy. The kinetic energy can be used to turn a turbine connected to a generator. This changes the kinetic energy into electrical energy which is really useful.
Some energy forms can be stored but others can't.
Electrical energy can be stored for a short while in a device called a capacitor but if it is changed into chemical energy in a accumulator (rechargeable battery), it can be stored for longer periods of time. Potential energy is a good way of storing energy too - there is gravitational potential energy (the energy of where an object is) and elastic potential energy (the energy contained in an object that has been twisted or bent without breaking it).