The estimated annual fuel usage for your project, measured in million British Thermal Units (MBtu) if your project units are in IP (inch-pound units) or Megajoule (Mj) if your project units are in SI (International System Units or Metric System). One Btu is the amount of heat required to raise one pound of water one degree Fahrenheit at one atmosphere of air pressure. One therm is equivalent to 100,000 Btu or 0.1 MBtu.
One joule is defined as a unit of energy equal to the work done when a force of one newton acts through a distance of one meter. One megajoule is one million joules. One megajoule is equivalent to 948 BTUs.