Utility production areas are often totally excluded, since some plants will have the areas included in their battery limits and other plants will use purchased or centrally supplied utilities. Usually the goal is to evaluate the energy performance of the product facility and not that of utility generation. For this reason, the main utility components of fossil fuel, steam, and electricity would be gathered separately. In some processes, chilled water or refrigeration and stream-to-stream heat transfer process should also be considered. Fossil fuel used as boiler fuel or as process feed or off-gas must be carefully
checked in the data validation process to avoid double counting.