Quad
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
- Energy production by country
 - Primary energy
 - End use energy
 - Fuel vs flow
 - Energy conversion technology
 - Or explore a random page
 
References
- ↑ APS Physics. (2015). Energy Units [Online]. Available: http://www.aps.org/policy/reports/popa-reports/energy/units.cfm [February 20, 2015].
 

