Calories (15 °C, NBS 1939)
The 15 °C NBS 1939 calorie is the amount of energy required to raise the temperature of one gram of water by one degree Celsius, from 14.5 °C to 15.5 °C, at standard atmospheric pressure. This specific definition was established by the National Bureau of Standards (NBS) in 1939.
Megawatt-hours
A megawatt-hour (MWh) is the amount of energy consumed when one megawatt (MW) of power is used for one hour. It is used to measure large-scale energy production or consumption such as power plants.