Electricity can be obtained from various sources such as water flow, wind, geothermal, coal, sunlight, nuclear, tidal waves, sea waves, and many other sources. We convert these energy sources into electrical energy. But how are these energy sources converted to electricity?
Because of the law of conservation of energy, electrical energy certainly comes from other energy sources. The process of converting energy into electrical energy is generally called electricity generation. Electricity generation is the first step in the presence of electricity in our homes. The electricity is generated by giant generators at the power plant facilities. The electricity is then distributed and distributed through transmission and distribution networks to our homes.
In fact, electricity has a distribution speed close to the speed of light. So, the electricity you use to turn on a lamp, use a computer, etc. is actually also generated and distributed almost simultaneously when you use it.
Because of the options for storing electrical energy are very limited and have large costs, electricity must generally be produced almost simultaneously following the electricity demand. For example, at night, electricity-generating machines have to work harder than during the day to meet people’s electricity needs.
Electricity comes from other energy sources which are generally primary energy sources (can be obtained directly from nature). These sources include coal, oil, natural gas, biomass, nuclear fuel (uranium), sun, wind, tides, high altitude lakes, rivers, and geothermal energy that supplies geothermal energy.
Energy sources are generally divided into 2 categories, primary and secondary. Primary energy sources are energy sources that are directly in nature, including crude oil, natural gas, coal, uranium, wind, water, biomass, and sunlight. While secondary energy sources are energy sources that are converted from primary energy sources, such as gasoline, LPG, biofuels, electricity, heat, and so on.
The majority of the different energy sources in electrical energy generation are essentially just different ways to make water evaporate. The steam is then used to turn the turbine. For example oil, biomass (like wood), and coal, are burned as fuel to evaporate water. This means that the three of them produce by-products which are greenhouse gases. Electricity generation accounts for around 1/3 of the total greenhouse gas emissions on earth.
Power plants that generate electricity by evaporating water are generally called Thermal Power Plants or Steam Power Plants. However, there are power plants that also use the same method, only called by different names. For example, a Nuclear Power Plant (NPP) uses heat from the results of nuclear reactions to evaporate water.
Fortunately, there are other methods to evaporate water or directly drive turbines that are more environmentally friendly than through combustion. For example, a Hydroelectric Power Plant that uses water energy to turn a turbine so that generators can produce electricity. Or Nuclear Power Plant (NPP) that utilizes heat from the nuclear reaction to evaporate water and turn the turbines.
Then How Do Generators Generate Electricity?
Electric generators generally utilize the magnetic induction method, which is by rotating the magnet near the coil or by rotating the coil near the magnet.
In principle, each magnet has two poles, they are north (N) and south (S) and each magnet affect the surrounding magnetic field. Changes in orientation or rotation of the magnet cause a change in the magnetic field. And changes in the magnetic field cause the movement of electrons in the cable/coil to produce electricity.
The magnet rotates so that it causes back and forth and repetitive movements. In other words, this method generates alternating current (AC).
AC Electricity Phase
The simplest AC electricity has only one phase, while the electricity that is generally generated in power plants has three phases.
Three-phase electricity can deliver a constant voltage above 0 compared to single-phase electricity that has a moment where the voltage is equal to 0, as in the picture above. Besides, three-phase electricity can output power three times greater than one-phase electricity.
From the distribution side, three-phase electricity can be supplied through 3 thinner cables which are lighter than one thicker and heavier cable. Therefore, we often pay attention to electric transmission towers supporting three or more cables simultaneously, even electricity poles on the roadside.
Transmission line towers that are commonly used in Indonesia are High Voltage Electrical Lines that have a voltage of 70 to 150kV, and Extra High Voltage Electrical Lines that have a voltage of more than 150kV.
Electric Supply Adjustment
The use of electricity every day is difficult to guess. From users who turn their devices on, charging, use daytime lighting, ironing, and so on, it all happens without being noticed by the power plant operator. Because of this, the power plant must be able to adjust the electricity supply according to the demands of the community.
Environmentally Friendly Power Plant
As mentioned earlier, electricity generation alone accounts for around 1/3 of the total greenhouse gas emissions on earth. In view of this, it is certainly very important to use environmentally friendly power plants. However, each clean and renewable energy solution has its own consequences and challenges.
For example, solar energy is a renewable energy source, and its maintenance costs are much cheaper. However, the use of this energy source is very dependent on the weather and climate, can only be used during the day, low efficiency (15-22%) and on a large scale would require a very large area. Nuclear energy is also currently still not fully acceptable to the public, especially related to accidents and the resulting waste.
You can also read more about Nuclear Energy at the following source.
Therefore, many electricity network systems use clean or renewable energy sources together with conventional energy sources. For example, Coal Power Plant which is controlled by electricity output adjusts to the output of the Wind Power Plant which is in one electricity grid system.
Electricity is a form of energy, and energy cannot be created. Therefore, we must process other energy sources into electrical energy. The most commonly used method is by magnetic induction, which is by moving (rotating) the magnet continuously near the cable/coil to produce electricity.
Sources and References:
- Turning Magnetism Into Electricity (Electrodynamics) – The Science Asylum
- Induksi Magnet – Wikipedia
- How Electricity Generation Really Works – Practical Engineering
- How Fast Does Electricity Flow? – BBC Science Focus Magazine
- Thermal Electricity | Thermal Energy – ENGIE
- Advantages and Disadvantages of Solar Energy – GreenMatch
- Energy Resources: Primary vs. Secondary – Watt Watchers of Texas