The Conservation of EnergyPhysics Essay: The Conservation of Energy Since the beginning of time, energy has pervaded our earth. Nowadays we rely on it to advance our technological developments. We also need energy for a number of other things, for example: to keep our bodies alive and healthy, to run our machines and other technical devices, we also rely on energy to keep us warm in winter and cool in winter 'summer. Energy is the ability to work. People and other things can run out of energy (e.g. a marathon runner), in which case they may no longer have the ability to work. In a mechanical situation, if a machine has energy it has the ability to apply a force to another body. There are many different forms of energy and there are many different places where energy can be collected. Forms of energy include: potential energy, kinetic energy, gravitational potential energy, elastic potential energy, and there are many more. Energy can be harvested in many ways using our natural resources from the environment, for example: solar energy (from the sun) and hydropower (where electricity is harvested from running water). Hydroelectric power is when electricity is generated by rotating coils of wire (rotors) between the poles of a magnet. The rotors are turned by water flowing over them. In a hydroelectric power plant the water is usually stored in a dam. When water falls and flows over the blades connected to the rotors, it loses gravitational potential energy and ga...