Abstract:

Learning in a secondary school is a complicated task, where the different subjects follow one another over time, without the student having time to assimilate the concepts and achieve significant learning. This fact is especially evident for subjects related to Science, Technology, Engineering, and Mathematics (STEM).

The STEMbach initiative at the University of Vigo (https://www.uvigo.gal/es/ven-uvigo/centros-secundaria/steam/stembach) is a Baccalaureate of Excellence in Science and Technology created under the Galician Digital Education Strategy EDUDixital 2020 of the Xunta de Galicia. STEMbach aims to promote the acquisition of key skills for the 21st century, both transversal and those more properly linked to the STEM field always from a broad perspective, not limited to these subjects, but transversal and in collaboration with the various sectors and social agents.

In particular, a project based on wave energy generation was carried out in collaboration between CIM-EPHYSLAB https://ephyslab.uvigo.es/) and the IES As Lagoas (http://www.edu.xunta.gal/centros/iesaslagoas/). The main goal of the project was to convert the mechanical energy of water waves into electric energy by using the wave generator Eólice located at Campus Auga Building.

Eólice is a small tank (200×36×20 cm) designed for educational purposes to teach students from primary school to university the properties of water waves. In this particular project, whose goal is the generation of electric power from water waves, a small buoy (3.1cm in radius) was placed into the wave flume to undergo the effect of a wave train externally imposed. The buoy moved a neodymium magnet by means of a fishing line and a pulley system in and out of a 12000-turn wire coil to generate electric power.

Different concepts and skills were developed during the project:
The first concept acquired by the students is the ability to generate renewable energy from sources such as the sea waves, the sun, or the winds, that are practically infinite and inexhaustible, in an attempt to reduce the CO2 footprint and achieve an economy free of fossil fuels.

The second concept is purely scientific and related to Faraday's Law previously learned in theory. This law states that the change of magnetic fluxes through coiled wires can generate electricity, the induced electricity being proportional to the change in magnetic flux. Thus, the greater the change, the more electricity is generated. Here, with a simple and inexpensive experiment, students can consolidate their knowledge of Faraday's Law.

Finally, an additional skill is collaborative learning, where the team, starting from a general objective, was able to approach a solution by trial and error. Neither the mechanism to generate power nor the configuration was defined from the beginning and the students were forced to follow different approaches, each with its drawbacks, before arriving at a final solution.

Keywords:

STEMbach, learning by doing, experimental project, wave tank.