Electrical Energy Auditing by Analyzing End-Use Energy Consumption: A Case Study of an Office Building in Tehran

Auditing electrical energy in buildings is a feasibility study consisting of a comprehensive assessment of a building’s electrical utilities in order to optimize energy consumption. In this paper a bottom-up method to estimate electrical loads is formulated that could help in disaggregating electricity use to specific end-uses in the absence of sub-meters in existing buildings. This method can be used for detailed benchmarking and identification of improvement opportunities. Implementation of the method in an office building, located in Tehran, showed a satisfactorily match (94.66% for off-peak, 88.69% for mid-peak and 94.46% for on-peak) exists between the calculated loads with the data extracted from electricity bills. The building electrical energy auditing showed a maximum share of consumption for office equipment (32%) and a lower consumption for lighting (28%), space heating and cooling (17%), domestic hot water (12%) followed by catering and other electricity end-uses (11%). Through interpreting the energy auditing results, strategies for increasing energy efficiency has been suggested.