terawatts

Terawatts (TW) is the SI unit of power equal to 10^12 watts. The prefix tera- denotes one trillion, so one terawatt equals one trillion watts. TW is used to express very large-scale power generation, transmission, and consumption, such as national electrical capacity or global energy throughput. It is important to distinguish terawatts from terawatt-hours (TWh), which are units of energy (power integrated over time).

In practical terms, 1 TW equals about 1,000 gigawatts. Since a modern large power plant ranges from hundreds of megawatts to a few gigawatts, the terawatt scale typically requires many plants. Global installed electrical capacity is on the order of several terawatts, and world electricity generation corresponds to a few terawatts of continuous average power, varying with demand and season.

Terawatts are also used in high-level comparisons of energy systems and in certain areas of physics. For example, high-power laser facilities can reach terawatt power levels for short pulses; for sustained power, even higher scales such as petawatts are discussed in research contexts.

As a point of scale, the Sun’s total power output is about 3.8×10^26 watts, vastly exceeding terawatt magnitudes and illustrating the wide range of power scales encountered in science and engineering.