6.3 Plug Loads

“Plug loads” refer to those many electricity consuming devices that are not permanently hard wired into the building electricity distribution system.  They include office equipment, kitchen and cafeteria appliances, portable heaters and coffee makers, and so on.  While small energy consumers individually, in total they can comprise a significant portion of the electrical load in the building.

Typically retrofits do not address these loads.  However, in assessing opportunities for savings, the auditor should consider what the impact will be of changes in usage patterns (e.g. turning off computers at the end of the work day) or in equipment selection (specifying energy efficient models for all new purchases—e.g. using Energy Star® compliant devices or similar guidelines).

Guide to Energy Efficient Equipment Selection

Energy Star® is a government run program developed by the US Department of Energy, and adopted in Canada (for one).  It provides energy ratings for a wide range of electrical devices, both domestic appliances as well as office equipment.  A comparison between compliant and non-compliant equipment is illustrated in the following example.  This calculation is done using a savings calculator available from Energy Star at

http://www.energystar.gov/index.cfm?c=bulk_purchasing.bus_purchasing

*  One unit is defined as having a central processing unit (CPU) and a monitor. NA = Not Applicable; see product assumptions.
** Please input this figure from the Program Compliant Products List at www.energystar.gov.  To find the Watts in sleep mode, refer to both the Computer List and the Monitor List.  Then, add the two numbers together and enter the total value into the appropriate cell above.

OPERATING COSTS FOR 1000 COMPUTER(S) AND 1000 MONITOR(S)

*Please note that all costs, except initial cost, are discounted over the products’ lifetime.  Annual costs exclude the initial purchase price.

BENEFITS OF ENERGY STAR FOR 1000 COMPUTER(S) AND 1000 MONITOR(S)

 *Please note that a payback period of zero years means that the payback is either immediate, or it is less than one year. Please keep in mind that this analysis provides a simple estimate of product savings.  To determine the true product savings, consult the individual EPA and DOE programs, or call 1-888-STAR-YES.