Annual Energy Use is the total amount of energy consumed by a building or system over a 12-month period, typically measured in kilowatt-hours (kWh), therms, or British thermal units (Btu). This metric forms the foundation for energy performance benchmarking, utility bill analysis, and efficiency improvement planning. Annual figures smooth out seasonal fluctuations and provide meaningful comparisons across different buildings and time periods.
Technical Details
Annual Energy Use encompasses electricity for lighting and equipment, natural gas or oil for heating, and other fuels used in building operations. Measurement occurs through utility meters and building energy management systems (BEMS) that log consumption at 15-minute to hourly intervals. Energy consumption varies significantly based on climate zone, building type, occupancy density, and operational schedules. A typical office building consumes 10-20 kWh/sf/year, while hospitals may exceed 100 kWh/sf/year.
Practical Significance
Tracking Annual Energy Use enables calculation of Energy Use Intensity (EUI) for benchmarking against similar facilities. This data supports utility rate negotiations, identifies abnormal consumption patterns indicating equipment failures, and documents savings from HVAC retrofits and operational improvements.