The quad is a unit of energy defined as 1 quadrillion (1015) BTU.[1] Quads are used in similar settings as the exajoule (1018 joules) when speaking of world or national energy supply/demand.

Generally, quads refer to primary energy rather than end use energy.

For further reading


  1. APS Physics. (2015). Energy Units [Online]. Available: [February 20, 2015].