Forms of energy and conservation of energy

In short: Energy is the ability to do work. It occurs in many forms and can be converted but neither created nor destroyed: this is the law of conservation of energy.

In more detail: Energy is measured in joules or, in everyday life, in kilowatt hours (kilowattstunde-(kwh)).

In detail

• Kinetic energy: Energy of motion, grows with the square of speed.
• Potential energy: Energy of position, e.g. a raised weight (schwerkraft-und-freier-fall).
• Thermal energy: Disordered motion of particles (waerme-und-temperatur).
• Electrical energy: Moving charges.
• Chemical energy: In food, petrol, batteries (chemische-reaktionen-grundlagen).
• Radiant energy: Light and other radiation (licht-und-farben).
• Conversion: A bicycle converts muscle energy into kinetic and thermal energy.
• Efficiency: Part is always “lost” as heat (erneuerbare-energien-ueberblick).