# Household Energy Management
## 2 Characteristics of Smart Appliances  
Smart appliances taking part in the application of the EEM algorithm operating in the household should have the following properties:  
* have specific power demand for a specified period of time,
* can be powered only at certain known intervals,
* the time during which these devices are powered is important for the functioning of the household. The group of smart appliances with the properties listed above, whose energy consumption can be managed, include:  
Figure 1: Power electronic converter in the process of the energy management at the household level. induction hobs, ovens, microwaves,
* dishwasher,
* washing machine and dryer,
* refrigerators and freezers,
* lighting,
* air conditioning system equipment with heat accumulators, flow and non-flow electric water heaters (boilers), floor heating,
* electric and hybrid vehicle batteries. The energy consumption of each consumer results from the parameters of their appliance and the way these are used. For proper operation of the EEM algorithm it is required to define appropriate appliance parameters. This mainly applies to determining if and when a given load can be used during power reduction. A very small number of types of appliances currently used in households have the possibility of gradual reduction of power. The article proposes the introduction of a work section (_WS_) in these appliances for manufacturers of the smart appliances. This will increase flexibility in reducing the power of such appliances and improve the comfort of their use in the household. The section should be understood as the phase of the appliance's work. An example of such an appliance in which _WS_ occurs can be a washing machine, e.g., prewash, main wash, spinning, etc. For each _WS_ (Figure 2) there will be independently determined values of minimum (_P_A_MIN) and nominal (_P_A_NOM) power parameters. The manufacturer, based on their own experience, will determine for each _WS_ whether at any given time the power reduction from _P_A_NOM to _P_A_MIN, with possibly more \(k\) levels of its changes, will not have a negative impact on the task carried out by the smart appliances. The introduction of a certain number of power reduction levels is possible in smart appliances intended for maintaining the set air and water temperature. Examples of this are boilers and electric floor heating, which are heat stores. Limiting the smart appliance power consumption may, from the user's point of view, be associated with a slight decrease in comfort, e.g., a lower water temperature in the boiler or a higher room air temperature obtained by the air conditioner. However, these slight inconveniences transform into reduced costs for energy consumed in expensive time periods. From the point of view of TSO and DSO, such action will increase flexibility and improve NPS security. Based on the example of smart appliances usage (Figure 2), the EEM algorithm will be run in: _WS_2, _WS_4 and _WS_5. Only in these _WS_, the EEM algorithm can choose a new power value (_P_A_SEL) in the range (_P_A_MIN, _P_A_NOM). _WS_3 presents a situation in which the manufacturer of the smart appliances has determined that for the correct operation of  
Figure 2: Example description of smart appliances parameters with the option of using it in the elastic energy management (EEM) algorithm. the smart appliances no reduction of power can occur. In this case \(P_{A\_NOM}=P_{A\_MIN}\). In contrast, \(WS_{1}\) may reflect the smart appliances standby time mode. In this case, for most of the time the smart appliance waits for 24 h to turn it on, power could be reduced to zero. For example, power reduction in standby time mode could consist in turning off the LED display indicating the current value of the hour, e.g., in the oven or microwave. The power of a single LED display, from the point of view of a single household does not matter much. However, for a larger scale, e.g., city or DSO, running the EEM algorithm in households to reduce power in \(WS_{1}\) may help to alleviate peak demand.