Digital dictionary

We deem it very important for every visitor to be able to understand our (web) texts. As such we have chosen to explain certain terms in more detail in "normal" English. Please feel free to contact us if you'd like further clarification.


  • An aggregate is a motor-driven generator for generating electricity.
  • A combustion engine is often used as a drive-motor. Aggregates are used in places where no or insufficient electrical power is available, such as in zones that lack connection to the electricity network. Aggregates can also be utilized wherever electricity must be available continuously, such as in hospitals. In these cases, they are usually permanently installed, and are referred to as emergency aggregates.

Work (or energy)

  • In physics, work is a measure of the work done, or the effort put forth by a source of power when moving a mass. Work is the force multiplied by the distance travelled.
  • The unit of work is the Newton meter (Nm), the same as the Joule (J), the unit of energy. Work is a form of energy. A Joule is approximately the work done by lifting a one-litre carton of milk ten centimeters.


  • A dynamo or direct current generator is a machine which converts mechanical energy, coming in through a rotating shaft, is converted into electrical direct current energy. The opposite of a dynamo is the DC motor, in which electrical DC energy is converted into mechanical energy.
  • "dynamo" (from the Greek δύναμις dunamis) used to be another name for an electric generator, but - after the development of the alternator - is now mainly used to indicate generators that generate direct current using a commutator. This being said, a bicycle's alternator is still referred to as a dynamo.

Electric energy

  • Electric energy, as shown on the electricity bill, for example, is expressed in power times the duration. For example, one kWh is converted into 1,000-Watt times 3,600 seconds = 3,600,000 Joules or 3.6 MJ.


  • A generator is a machine that converts mechanical energy, coming in through a rotating shaft, into electrical energy. In power plants, the rotation of the shaft is often handled by a turbine.
  • The conversion in the generator is based on induction, the physical phenomenon that generates an electrical voltage across a conductor located in a changing magnetic field (or moving in a magnetic field).


  • A force is a physical quantity that can cause an object to change its shape or speed. A force can be converted to perform work. Forces can also be named according to their cause or action, such as frictional force, gravitational force, and centripetal force.
  • The international SI unit of force, the Newton, is named after Sir Isaac Newton.


  • A machine (Latin for tool) is a device made up of a frame, a drive mechanism and other specific parts.
Engine or motor

  • An engine or motor is a machine that converts certain types of energy into kinetic energy. Usually this it concerns a circular movement, but linear movements are also possible.
  • Engines are distinguished according to the form of energy supplied. There are:
    1. Electric motors that use electro-magnetic energy.
    2. Heat engines are based on thermodynamic laws. In these engines, the aforementioned conversion takes place as a result of temperature differences. These can take place externally (e.g. the Stirling engine) or be caused by internal combustion. The combustion, in turn, is then a conversion of chemical energy into heat energy.
    3. Flow energy can be used to power a wheel or a turbine.

The 'De Cruquius' pumping station, which was used to drain the Haarlemmermeer in The Netherlands, has a piston diameter of 3.66 meters, making it the world's largest steam engine.

Steam engine

  • The invention of the (industrial) steam engine marked the beginning of the industrial revolution. For the first-time, work power could be realized everywhere to drive machines, whereas before that time, people had to work using manual power, draft animals, watermills and windmills. The steam locomotive is a well-known application of the steam machine.
  • A steam engine is an engine (or in a broader sense, a machine) that produces mechanical work by means of pressurized steam (often as a result of heating by burning coal). A steam engine has a relatively low return, as only part of the steam's energy is converted into kinetic energy.
  • Piston steam engines are no longer utilized today, except in a few steamships still in use. Where there is a need for an independent power source, a steam turbine, diesel engine, petrol engine or aggregate is almost always more efficient, cheaper, less polluting and/or lighter.


  • Power is a physical quantity of energy (work) per unit of time.
  • The SI unit for power is the Watt, named after James Watt. A Watt is a Joule per second, Watt = J/s.

For any questions, feel free to contact

Pim Bekking, CEO and Founder Be-Rex B.V.
T: +31 318 84 05 69 | E:
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