Quad (unit)
A quad is a unit of energy equal to 1015 (one quadrillion) British thermal units (BTU). The term is primarily used in the United States and in global energy discussions involving the U.S. as a way to represent very large amounts of energy.
One quad is approximately equivalent to:
- 293 terawatt-hours (TWh)
- 1 exajoule (EJ)
- 170 million barrels of crude oil
- 1 trillion cubic feet of natural gas
Quads are typically used to quantify national and global energy consumption and production. For example, the annual energy consumption of a country or the annual production of a particular energy source (like coal or natural gas) might be expressed in quads. The unit allows for convenient comparison of the relative contributions of different energy sources to the overall energy mix, even when these sources are measured in vastly different units initially.