The core of the HES tariff functionality is a load processing “module” that translates annual electricity consumptions for several end-uses, along with hourly outputs from the DOE-2 model, into monthly utility bills.
Load processing follows the general flow shown in Figure 12. Three types of servers (DOE-2, Witango, and TAP) perform different parts of the load processing. To ensure consistency, all load calculations are based on the year 2005 calendar. There are several distinct steps necessary to transform annual electricity into monthly electricity bills. First, the non-HVAC end-uses (appliances, lighting, etc.) with similar load shapes need to be combined then allocated to an 8760-hour profile according to the appropriate load shape curve. Second, all the 8760 hourly profiles for the house (including the hourly output from the DOE-2 heating and cooling simulation engine) need to be aggregated to form the hourly profile for the house. This profile is used to identify the monthly peak demand in each TOU bin as well as the total monthly electricity consumption for each bin. These numbers are sent to TAP, which returns the monthly electricity bills. Finally these bills need to be allocated back to the individual appliances.