A typical chart using quads.

A Quad is a unit of energy equal to 10¹⁵ BTU,^[1] or 1.055 × 10¹⁸ Joule or 1.055 Exajoule (EJ) in SI units. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... The British thermal unit (BTU) is a non-metric unit of energy, used in the United States and, to a certain extent, the UK. The SI unit is the joule (J), which is used by most other countries. ... The joule (IPA pronunciation: or ) (symbol: J) is the SI unit of energy. ... Look up si, Si, SI in Wiktionary, the free dictionary. ...

The unit is widely used in discussing world and national energy budgets. World primary energy production in 2004 was 446 Quad. [1]

References

1. ^ Energy: Glossary. Department of Materials Science and Engineering, University of Illinois Urbana-Champaign. “QUAD: an amount of energy equal to 10¹⁵ BTU.”