Smart Home Research Papers - Academia.edu (original) (raw)

The paper presents the operational results of a real life residential microgrid which includes six
apartments, a 20 kWp photovoltaic plant, a solar based thermal energy plant, a geothermal heat pump,
a thermal energy storage, in the form of a 1300 l water tank and two 5.8 kW h batteries supplying, each,
a couple of apartments. Thanks to the thermal energy storage, the solar based thermal energy plant is
able to satisfy the 100% of the hot water summer demand. Therefore the thermal energy storage represents
a fundamental element in the management of the residential demand of thermal energy. It collects
renewable thermal energy during day-time to release it during night-time, effectively shaving the peak of
the thermal energy demand. The two electric storages, on the other hand, provide the hosted electrical
subsystems with the ability to effectively increase the self-consumption of the local energy production,
thus lowering the amount of energy surplus to be sold back to the grid, and increasing the self-sufficiency
of the microgrid. For instance, the storage has supported self-consumption up to the 58.1% of local energy
production with regard to the first battery, and up to the 63.5% with regard to the second one. Also, 3165
and 3365 yearly hours of fully autonomous activity have been recorded thanks to the first, and the second
battery respectively. On the other hand, the yearly average efficiency amounts to 63.7%, and 65.3%
respectively, for the first and second battery. In the second part of the paper we propose a computational
framework to evaluate the overall performance of the microgrid system, while accounting different operating
conditions and energy management policies. From this perspective, the framework acts as a useful
modeling and design tool, to assess the opportunity of employing alternative energy management system
topologies and strategies. Eight different configurations, with growing complexity, have been derived
from the original system on purpose. The simulations, carried out based on real data related to one-year
time period, have provided results showing that, the higher the integration level of electrical and thermal
storage is, the higher degree of self-sufficiency can be achieved by the microgrid, and, in turn, the more
consistent the yearly energy saving become. Nevertheless, despite the energy cost reduction achievable with the availability of storage systems in the Leaf House, their high investment cost made them not
really profitable at the current price conditions for devices and energy purchase.