Volume is the measure of how much of something is involved in a trade

Volume = Quantity (but the term Volume is nearly always used in preference)

Hence in energy trading volume may have dimensions of energy, mass, weight or volume

Detail

Volume is one of the important attributes of a trade

Volume may be specified:

As a total for the entire trade

By day, month or some other period for the duration of the trade

Volume has units of quantity according to the commodity:

Mass (often incorrectly called weight) - often used for coal, oil and other non-gaseous commodities

e.g. metric tonne (T), kilogrammes (kg)

Volume - sometimes used for gaseous and liquid commodities

millions cubic feet (mcf), barrels (bbl), gallons

Energy - may be used for any commodity

e.g. therms, Megawatt hours (MWh)

For gas and electricity trades it is generally more convenient to trade in quantities of energy

Other energy commodities are usually measured in volumes of mass or volume since this is more practical to measure at delivery

Volume traded will directly affect the traded position of that commodity

Volume may be constant over the duration of the trade, or may vary over the different delivery periods: the delivery volumes are defined in the Schedule of the trade