Energy harvesting is a revolutionary technology that harvests and converts various forms of micro-energy from our daily lives into electricity, which has the potential to reduce machine charging and battery usage and maximize energy efficiency.
Smartphones, watches, laptops, light bulbs, heating. What do they all have in common? They’re powered by energy. Almost every device we use requires energy, which is converted into various forms to be used. Some devices convert electrical energy into light energy, while others convert it into kinetic energy. For example, your favorite light fixture converts electricity into light energy, and your car burns fuel to get kinetic energy. However, most of the energy in these processes is lost as heat energy. This is a common phenomenon in our daily lives, but it’s also something we often overlook.
Energy efficiency is the ratio of the useful energy output to the energy input. For example, fuel cells have an energy efficiency of around 60%, which is quite high. However, the remaining 40% of energy is still released as heat and wasted, which can be very inefficient. We often think we use electricity efficiently, but in reality, a lot of energy is wasted. Especially in large-scale industries and transportation, energy losses are greater than we can imagine. It is necessary to reduce these losses in the energy conversion process, so that we can maximize the use of energy resources.
Energy harvesting is a technology that has been gaining attention recently. Energy harvesting is a technology that collects energy that would otherwise be wasted in our daily lives and converts it into electricity, utilizing various forms of energy that we often overlook. On a small scale, it captures the heat energy emitted by the aforementioned devices when they run, or converts the slight pressure or friction energy we experience when we touch our smartphones or type on our laptop keyboards into electricity. On a larger scale, you can even capture and utilize the vibrations and heat generated when a car or airplane is traveling.
Energy harvesting requires a device that can effectively collect the energy emitted by its surroundings. There are several principles that work in these devices. The first is the piezoelectric effect. The piezoelectric effect is the conversion of mechanical energy, such as vibration, pressure, or shock, into electrical energy through piezoelectric devices. This principle can be found in everyday life, for example, in recorders that store sound waves in the form of radio waves. Applying this principle to energy harvesting, it is possible to generate electricity from the pressure generated when a person bends a knee or elbow joint, or to develop a remote control that converts the kinetic energy of pressing a button into electricity. This is one way to efficiently use the energy that is naturally generated in everyday life.
Another principle that applies to energy harvesting devices is the thermoelectric effect. The thermoelectric effect is the relationship between thermal energy and electrical energy, specifically the Peltier effect. When two materials with different temperatures are joined, the temperature difference creates a voltage difference and current flows. By attaching this device to a device, the heat generated by our bodies or machines can be converted into electrical energy for use. For example, this technology can be applied to portable electronics to convert heat energy from a user’s walking into electricity to charge the device.
Other principles that can be used for energy harvesting include photoelectricity and electromagnetic resonance. Photoelectricity, which is the movement of electrons in a metal when light above a certain frequency is shone on it, can be used to convert light energy from sunlight or light bulbs into electricity. This technology can be utilized to efficiently harness light energy to generate electricity without directly harnessing sunlight. Next, electromagnetic resonance is the generation of electrical energy when an externally applied alternating magnetic field causes the electron or nuclear spin system of an atom with a magnetic moment to absorb energy at a resonance frequency. This can be used to develop a system that converts the energy of the magnetic field generated by scratching or swiping a card into electricity.
While energy harvesting technology is still in its infancy and not yet commercialized, the possibilities are endless. These are just a few examples of technologies that are in the development or experimental stages. But in the future, when all of these energy harvesting methods are perfected and integrated, we won’t need to charge our machines separately or carry batteries with us. Innovative devices like wearable computers will emerge, which will be able to absorb different types of energy from the environment and use it as their own energy. We may even see a time when a simple wristband will be able to effectively absorb and utilize the various types of energy generated in our daily lives.
And maybe, just maybe, energy harvesting technology will maximize energy efficiency, slowing down the depletion of our planet’s dwindling resources. This could play an important role in solving the energy challenges we face, and it could also make a significant contribution to protecting the environment. If this technology is commercialized, it will have a positive impact not only on the environment, but also on humanity as a whole. I hope that this breakthrough technology will be realized in the near future, and I can’t wait to see how it will change our lives.
