The term Energy Density relates the mass of a fuel to the amount of energy that is stored within the fuel. It is defined as "the amount of energy stored in a given system or region of space per unit volume, or per unit mass" (Wikipedia). The units associated with Energy Density are J/kg and J/L. The energy sources with the highest Energy Density are nuclear fusion and fission. The energy density of a fuel is closely related to its Enthalpy of Combustion, which refers to the amount of energy that is released when a known amount of fuel is combusted in excess oxygen (Wikipedia).

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Sources:

1. "Energy Density." Wikipedia. 11 Mar. 2009 <www.wikipedia.com>.
2. "Standard Enthalpy change of Combustion." Wikipedia. 13 Mar. 2009 <www.wikipedia.com>.

Authored by: Michiel Bustraan