You can’t manage what you don’t measure

The Energy Policy Act of 2005 requires federal agencies to install metering by October 21, 2012. This equipment will provide a snapshot of energy use and identify areas that need increased efficiency. Metering occurs on many levels and at a variety of points in a building’s system. Ultimately the metering method you choose depends on your main objectives and resources.

Guidance for Electric Metering in Federal Buildings
E-Mon “Green Class” submeters