How electricity is transmitted through a power grid

Power transmission

Electricity is the transmission of electrical energy. It is characterized by current strength and voltage. The current strength is the amount of charge that flows through a line per unit of time. The voltage stands for the electrical energy that a charge carries with it. The charge receives its energy in a power plant, for example. From there it is transferred to households and businesses, where electrical devices convert the energy into a usable form, such as heat for heating.

As little energy as possible should be lost during transport. However, heat loss occurs when the charge “collides” with the atoms in the conductor. For this reason, a low current strength is used for long distances, because the fewer charge carriers flow, the fewer can collide. In order to still transmit a high output, each charge carries a lot of energy. High voltage is used for this. It is dangerous for people and electrical devices: At high voltage, the air no longer acts as an insulator - flashovers can occur. Therefore, you have to gradually bring the current at the target to a lower voltage without losing power. This happens in substations with transformers: They increase the amperage, while at the same time the voltage decreases. The energy stays the same.

However, transformers only work with alternating current - the decisive reason why alternating instead of direct current comes from the socket. While with direct current the charge always flows in one direction, with alternating current the direction of movement is reversed periodically. In European networks, the charge swings around its position 50 times per second: at a frequency of 50 Hertz. On average, it does not leave its place, but can still transfer energy to the consumer. In everyday parlance, electricity is "consumed". But the number of charges in the line remains constant. An electrical device only takes the electrical energy from the power grid and converts it into another form of energy.

19th February 2016