Energy Management - Measurement for Cost allocation, bill checking and sub-billing

From Electrical Installation Guide
HomeMeasurementMeasurement applicationsEnergy Management - Measurement for Cost allocation, bill checking and sub-billing

Bill checking is the process that allows a final energy user to verify that the invoice sent by the energy supplier is not mistaken.

As described in Table 9 of IEC TR 63213:

  • Cost allocation is the process that allows a facility manager to account for energy costs from internal cost centres (process line, test and inspection, administration) that consume energy
  • Sub-billing is the process that allows a landlord, property management firm, condominium association, homeowner association or other multi-tenant property to spread out an invoice over energy users (assign portions of invoice to users), for measured usages or services. This fee is usually combined with other tenant’s facility fees. The landlord does not commit on the quality of the supply.
Fig. S4 – Simplified overview of EM/cost management application
Application Interaction between: 2nd party needs to access the energy index displayed on the meter operating in his premises? Transaction
1st party 2nd party Profit on kWh price Money exchange mean
Cost allocation Final customer Cost centre managed by the final customer No, the meter is usually installed in the 1st party premises[a] No No money exchange
Sub-billing Final customer Final energy user No, the meter is usually installed in the 1st party premises[a][b] No Fee (combined with other fees)
  1. ^ 1 2 When the meter is located within a switchboard, a panel or a cubicle, usually the meter display cannot be accessed for safety reasons, except by the facility manager. The meter index is then transmitted to a remote system via a communication line.
  2. ^ In case of profit on kWh price, the first party would become a wholesaler, it would then not be a sub-billing application anymore.

Since the meter used for sub-billing is typically installed in electrical room not accessible by the tenant, the risk of fraud is very limited. This is why devices complying with IEC 61557-12 can be used for sub-billing applications. Billing meters complying with IEC 62053-21 may also be used.

Attention should be put on environmental aspects where the device used for sub-billing needs to fit temperature environment, sometimes more severe in switchboard or panels. This is why, in any case, measuring devices used in for sub-billing in switchboards and panels need to comply at least with IEC 61557-12.