Capacitors Embracing the Green Revolution

One of the pressing concerns of our age is environmental crisis. With the progressing technological evolution, the need for energy conservation and harvesting has increased. Harvesting energy is not an easy task, and most of the time, generating energy creates pollution in the environment. To deal with it, the international community has changed its approach so that it is now focused on identifying the areas where energy is being wasted and rectifying those issues instead of producing more energy.

The low power factor is one of those aforementioned issues. Power factor is a measure of lag in current with respect to voltage. Its value varies from zero to one.  This lag creates a component of electrical power that is not being used and keeps oscillating between generation and consumer ends. This circulation of power dissipates energy in the form of heat and also creates extra load on the generation end. A power factor issue arises due to the presence of inductive loads, such as electric motors, fans, etc. Now the power companies have started to penalize industries that have high inductive loads and a very low power factor.

The industries are taking initiatives to increase their power factor. There are two methods of a power factor correction. One is using active circuit elements, such as a buck converter or a boost converter. This method is very expensive and has a large payback period. The other method is passive power factor correction using capacitors. In this method, pre-calculated value capacitor banks are connected to the inductive system. The capacitors nullify the effect of an inductive load and bring the power factor closer to one. In case of industries, this reduces the wasted power dramatically and the energy strain on generation end decreases.

Due to long distance transmission of electrical power and with the presence of several transformers in between, the shape of a pure sine wave gets distorted by high frequency noise components. Nearly all of the electrical appliances are designed to operate specifically with pure sine wave voltage. These noise components reduce the efficiency of appliances and waste a component of power. Capacitors are used to absorb these high frequency components partially and improve the efficiency of the overall system.

supercapacitors

An interesting development in the field of power engineering is the creation of supercapacitors. Supercapacitors can be considered to be a hybrid of electrochemical cells and capacitors. These capacitors have very high value of capacitance (around 3000 Farads) and have very high energy densities. These capacitors cannot be used for conventional capacitor applications. They can provide very large values of currents for a small amount of time. This is the property of supercapacitors that has been exploited by engineers in the field of automobile engineering and generation of electricity by non-conventional means.

Energy generation through wind turbines is a cheap and pollution-free process. But aside from its perks, generating energy using wind as a driving force is not that easy. It is a complicated process that has to account for direction and speed of wind. If the direction of wind changes a bit, the speed of turbines is reduced and it becomes necessary to change the angle of the turbine blades. Now this task requires power, which the turbines can’t have unless they are operating at optimal speed. This problem is solved using supercapacitors. Supercapacitors store energy when the turbine is operating under optimal condition and provides energy bursts to change the angle of blades when the angle of wind changes. This ensures that the turbines keep operating at optimal speed and voltage at the generation end remains in under allowable range.

Another application of supercapacitors is in solar generation systems. Continuous, uninterrupted generation of electrical power is also important here. Supercapacitors can account for sudden fluctuation in voltage of photovoltaic systems due to reasons like cloud cover. This eliminates the need for maintenance of voltage and frequency at the main grid.

An interesting use of supercapacitors is in hybrid vehicles. In hybrid vehicles, braking energy is stored in supercapacitors and is used for starting the engine. Vehicles equipped with supercapacitors save 10 to 15% more energy as compared to conventional vehicles. Other advantages include less carbon dioxide emission, silent startup, low vibration, and ultimately less frequent maintenance. New F1 racing car models are equipped with supercapacitors, which further increase the speed of these vehicles.

Quantum effect supercapacitors are being developed to take the place of existing supercapacitors. They have relatively higher energy densities and are bound to increase the efficiency of systems that use supercapacitors.

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