For the planning of buildings and districts, the plug load electricity demand plays an important role. It describes the electricity demand for lighting and electrical devices.

Plug loads

Plug loads are the electric load consumed by household appliances for general use or for lighting. Household appliances in residential buildings include, for example, hair dryers, stovetops, toasters, washing machines, televisions or refrigerators. The consumption profile and total annual consumption are largely determined by the user behavior of the building's occupants. The electricity demand used for lighting is subject to seasonal fluctuations: In winter, this is greater than in summer due to the shorter days. The control of the building lighting (manual, central, presence-dependent by means of motion sensors) also has an influence on the annual consumption. Standby losses account for a significant portion of the total electricity demand. Ross and Meier (2000) found that in Germany, Japan, the Netherlands, and the U.S., 10% of national residential electricity consumption is attributable to standby functions. In addition, as the use of electric vehicles increases, electricity demand for e-mobility will account for an increasing share of electricity demand in the future.

In the nPro tool, literature values for the area-specific plug ploads are available for a large number of building types.

Electricity demand by building type

Scientific literature and relevant national standards contain numerous data on the user electricity demand of buildings. Table 1 lists the electricity demands for various building types. For kindergartens, the electricity demand per square meter of usable floor space is about 20 kWh/m² per year. For hospitals, this value is about a factor of 4 higher (80 kWh/m²) due to the higher lighting density and higher electricity demand for medical equipment. In the case of libraries, lighting accounts for a considerable share of the electricity demand, resulting in area-specific requirements of around 40 kWh/m². Gyms, shopping malls and restaurants have a high area-specific electricity demand.

Table 1: Plug loads for different building types

Building type	Electricity demand in kWh/m²
Kindergarten	20
Hospital	80
Library	40
Administration	20-30
Cinema	60
Office (without air conditioning)	35
Hotel	55-65
Hairdresser and cosmetics	65
Shopping center	85
Restaurant	70-95
Gym	120

Sources

Bekanntmachung der Regeln für Energieverbrauchswerte und der Vergleichswerte im Nichtwohngebäudebestand. Bundesministerium für Wirtschaft und Energie. 2015.
L. Pedersen: Load Modelling of Buildings in Mixed Energy Distribution Systems. PhD thesis. 2007.