Linking intra-day variations in residential electricity demand loads to consumers' activities: What's missing?

An increasing interest in the representation of the intra-day variability observed in domestic electricity consumption patterns has driven the development of various modelling frameworks that incorporate consumer behavioural patterns as a key element for the simulation of electricity consumption. Some of the existing models produce reasonable representations of the broader characteristics of user activity patterns, typically rendered as dwelling occupancy patterns. However, when these activity patterns are used to produce estimates of the electricity demand loads associated with such activities, little attention is paid to the links between activities and the actual use of the electric equipment responsible for the production of the actual demand loads. Instead, the simulation of demand loads from activity patterns is ruled by simplifying assumptions that mask the reality behind those links. This paper therefore seeks to unpack the relationship between activity and electricity demand profiles by focussing on the underlying activity patterns in more detail, and how these relate to the usage patterns of the associated appliances. These relationships are studied based on currently available datasets. The analysis of the activities associated with the use of more than one appliance revealed the differences between the likelihood of each appliance being activated throughout the day relative to user engagement in the activity the appliance is associated with. In practice, what this shows is how each appliance's share of the demand load associated with the activity varies throughout the day. As a result, the power consumption associated with a particular activity is subject to the same kind of variability; activity-related demand. The results of this analysis can be used in conjunction with current or new modelling approaches with a view to linking the user activity patterns with the simulation more of realistic electricity demand loads