Which type of power is typically used globally due to its high efficiency in transmission?

Three-phase AC power is favored worldwide for its high efficiency in transmission, particularly for long distances. This type of power allows for more effective use of electrical infrastructure because it can transmit larger amounts of energy with less voltage drop over a distance. The three-phase system achieves this by using three alternating currents that are offset by 120 degrees, resulting in a more constant power supply and smoother operation of electrical equipment.

In contrast, single-phase systems, while simpler and often used in residential applications, are less efficient for large-scale power distribution. They are generally limited in the amount of power they can transmit compared to three-phase systems. Single-phase AC tends to have a higher voltage drop over distance, which can lead to inefficiencies in power delivery.

Single-phase DC and three-phase DC are not commonly used for power transmission on a large scale due to technical limitations. DC power, while useful for specific applications such as electronics and batteries, requires different infrastructure for transmission, typically involving more complex and costly conversion systems to handle voltage changes. In contrast, three-phase AC systems can be easily transformed to different voltages using transformers, allowing for more flexible and efficient distribution networks. This inherent efficiency and reliability make three-phase AC the preferred choice in power transmission globally.