What type of energy can be found in which energy source?
Overview of where the energy stored in primary energy sources comes from and what form of energy it takes.
Information and ideas:
Students can think about the process on which all sources of energy are ultimately based. Which source of energy will be important in the future and why?
The tidal range example has special educational value for physics classes, since it appears at first glance to be a perpetual motion machine. The question of “where does the energy of a tidal power plant come from?” cannot be truly answered by the statement “from the difference in water levels (m x g x h). It may be clear to anyone that the moon does the lifting work, but where does it get the energy to do that? After all, wherever energy is “gained” somewhere, it must be “lost” somewhere else. The correct answer is that the moon’s gravitational pull shifts the water masses of the oceans, which ultimately causes a slowdown in the earth’s rotation. The mechanical energy obtained in a tidal power plant therefore ultimately comes from the primary energy source of “the rotational energy of the Earth”.