Keeping the Earth Safe and SOUND
When people discuss the most promising renewable energy options (solar, wind, etc), there seems to be one common omission: sound energy. With revolutionary ideas being developed over the years that involve using the sun, wind, and water to create a viable source of electric power, renewable sound energy hasn’t quite gained the popularity of some of the other methods but nonetheless is an effective choice that researchers have to look at.
Sound energy occurs when objects vibrate. The noise created by this vibration, whether heard by humans or not, is sound energy. One of the most beneficial aspects of sound energy is its presence in every part of the world. Humans, animals, and even inanimate objects are creating sounds with each passing second. Therefore, sound energy is available as much as solar or wind energy.
This graphic shows that sound energy can come from a variety of sources
Through the process of electromagnetic induction, sound vibrations can transform into electrical energy. Electromagnetic induction generates electrical current using a magnetic field. When a magnetic field and a conductor, such as a wire coil, move in relationship to one another, electromagnetic induction occurs. As long as the conductor is in a closed circuit, current flows wherever the conductor crosses the lines of the magnetic force. This process shows promise for a larger scale of renewable sound energy.
A broader term that can be used to describe this process is piezoelectricity, which uses unique crystals to convert mechanical energy (e.g. sound wave energy) into electrical energy. When compressed, the crystals act as conductors. The crystals structure changes as they acquire a net charge. This charge is what is converted into electrical current. Piezoelectricity unites the electrical and mechanical states of the piezoelectric material. Under compression, the material used has a current flow that changes its polarization to become an electrical charge, known as a net dipole moment.
Here is a model of piezoelectricity in Quartz - another type of piezoelectric material. It is shown how the effect of compression changes the structure and charge and causes the net charge.
As we know, sounds constantly fill our environment. Like all energy, sound wave energy has the potential to generate electricity. Just like the sun and breeze provide unlimited solar and wind energy, sound energy is renewable because sentient beings and insentient objects constantly produce sound. While the principles of energy production and sound waves have been mastered for years, the technology to convert sound energy to electricity is still in its early stages. However, as scientists and technicians investigate and improve the technologies involved in sound-generated electricity, sound energy may become a mass-producer of electricity. This may sound far-fetched given its current status, but it is important to remember that solar and wind energy were once dreams as well.
