According to the US Energy Information Administration, lighting, office equipment, and personal computers account for approximately 25% of total building energy use in the United States. 

To maximize electrical energy efficiency in buildings, Green Building design addresses electrical consumption in buildings by optimizing the various electrical systems.

Lighting

Advances in solid state lighting, and lighting controls have enabled tremendous reductions in installed lighting power density.  By setting LPD reduction targets beyond ASHRAE 90.1, projects are forced to consider the most efficient fixtures as well as maximizing options for the use of natural daylight.  To assist with reducing the electricity consumption; available utility incentives for LPD reductions, fixtures, and controls can offset the potential incremental cost premium for the most efficient technologies.  With fixture technology advancing at such a quick pace, consider specifying DLC certified fixtures.  Amongst other things, the Design Light Consortium certification standard verifies fixture efficiency and longevity.

Efficient lighting design should address general and task specific lighting options, as well as the overall occupant experience.

Process Loads

Electrical energy consumption in process loads is well addressed through the use of associated controls.  Install variable speed drives to modulate electrical energy consumption for process equipment including building fans and pumps. To the greatest extent possible, use controls to take advantage of process equipment setbacks and variances in space occupancy.  A well selected occupancy sensor has the ability to switch off lighting fixtures and HVAC fan coil units in unoccupied spaces further reducing unnecessary electricity consumption.

Plug Loads & Metering

It is difficult to manage that which you have no information about, or control over. To that end, depending on your space, consider sub-metering electrical system including lighting, process loads, and plug loads. Sub-metering can provide consumption information at a level of granularity necessary to manage, or ensure the efficient operation of electrical systems.  An EPAct 2005 study suggests consumption awareness gained through metering has the potential to decrease and maintain energy consumption reductions by 2%.

Additional information is available on this site related to Submetering and its use in Measurement and Verification processes.