What term is used to express the amount of energy produced from burning a standard amount of fuel?

The term that expresses the amount of energy produced from burning a standard amount of fuel is known as the Calorific Value. This term encompasses both the Higher Heating Value (HHV) and the Lower Heating Value (LHV). The Higher Heating Value refers to the total energy released when the fuel is combusted, including the latent heat of vaporization of water in the combustion products, while the Lower Heating Value excludes this latent heat.

In practical applications, the Lower Heating Value is often used because it provides a more realistic measure of the energy available for use, as it accounts for the energy that is not recovered when water vapor in the exhaust is not condensed. Thus, while both HHV and LHV are valid ways to measure energy output, Calorific Value is the broader term that encompasses these measurements, making it the most appropriate and accurate choice for expressing the energy produced from fuel combustion.

Comparing this to combustion efficiency, which measures the effectiveness of the fuel's energy conversion during combustion, it is distinct from the calorific values that directly quantify the energy available from the fuel itself.