Old question, but I'd like to point out that there can be two _two_ peak demand profiles when the model has a tariff with time of use demand charges; (1) the builing's peak demand profile and (2) the utility's peak demand profile, which may or may not be coincident. See the chart below for an example comparing the "Facility" demand from the Electricity:Facility meter and the "Utility" demand from the Tariff Report in EnergyPlus.