5.1.1. Power Layer

In the power layer, each EES component is described by a model. More specifically:


Table 1 collects the most relevant power characteristics of these components, plus the initial cardinality (# of elements) considered in the initial installation.

The power sources need input traces of irradiance and wind speed, which have been downloaded from the datasets of the National Renewable Energy Laboratory's (NREL's) Measurement and Instrumentation Data Center (MIDC) [51]. The time scale of irradiance and wind speed traces (one sample per minute) is longer that those of the load (one sample per second). We adopted the conversion methodology proposed in [9] to solve the issue of different time resolutions.

The *power bus* implements an initial *non-cost-aware energy management policy* similar to the one proposed in [52]: AC loads are satisfied by the renewable power sources whenever possible, and the battery pack is used to compensate whenever necessary (until its state of charge reaches a minimum of 10%). If the sum of energy stored in the battery pack and the power generated from the power sources cannot satisfy the AC loads, the houses purchase the missing energy from the grid. Otherwise, if the demand of the AC loads is less than the total power generation of the power sources, the unused power is used to charge the battery pack until it reaches 90% SOC, and then it is sold back to the grid.
