What is defined as the transmission level voltage?

The transmission level voltage is defined as the range of voltages used to transport electricity over long distances from power plants to substations. Typically, this is recognized as 138,000 volts and above, extending up to 765,000 volts or higher. This high voltage is utilized to minimize energy losses during transmission, ensuring that power can be efficiently delivered across vast distances.

High-voltage transmission systems are essential for practical electric grid operations because they allow for the efficient movement of large quantities of electricity. The higher the voltage, the less current is required to transmit the same amount of power, which reduces I²R losses (heat losses due to resistance in wires). Consequently, the choice that includes voltages from 138,000 volts to 765,000 volts or more accurately reflects the accepted definition of transmission level voltage in the context of electric utility operations.

Other voltage ranges mentioned do not meet the industry standard for what constitutes transmission voltage. For instance, lower voltage ranges fail to encompass the necessary thresholds for efficient long-distance electricity transport, thus do not qualify as transmission level.