In energy trading terms an asset is something an organization owns that can physically provide, transform or move an energycommodity, such as a gas field, a power station, or a refinery
Detail
In trading terms many assets that transform or help to move a commodity are in effect an option on a spread:
A gas fired power station acts as an option on a spark spread; if we choose to run it we provide the gas (and the carbon) and in return we get power