Thermal load estimation of apartment buildings for electrification analysis of energy communities

Nowadays, one of the biggest challenges to face in the energy sector is the transition to more sustainable methods of production and consumption of energy. In order to achieve this goal big changes, mainly focused on energy saving, are needed. Collective Self-Consumption and Energy Communities are going to play a key role in this transition, enhancing the efficiency of consumption and bringing benefits to both citizens and environment. Thanks to this new kind of organization, there is going to be a switch from the current electricity system, mainly centralized and based on fossil fuels, to a decentralized system, mostly powered by green and non-polluting energy. The aim of this master’s thesis is to perform a techno-economic analysis of the energy consumption of an apartment building, in the form of a group of collective self-consumers. The work starts with the choice of a typical apartment building to be used for all the simulations. This step is followed by the creation of a simplified thermal model of the same construction, with the subsequent estimation of the thermal load of the building. At this point, the analysis of two different scenarios is carried out. In the first case all the thermal load is supplied by a traditional boiler, while electricity is in part produced by a photovoltaic system and in part bought from the grid. When the electricity production from PV fulfills the whole electric demand, the surplus is sold to the grid. In this scenario, the whole electric consumption is referred to the standard consumption of the private electric devices used inside the apartments, and this is the case of a virtual collective self-consumption. The second scenario presents an improvement: a heat pump is introduced in order to reduce the usage of the boiler (and to reduce the amount of burned fuel), switching part of the thermal load into electric. In this scenario, the utilization of the heat pump is preferred: the boiler only works as a backup when the whole thermal load cannot be fulfilled by the heat pump and in the rare cases in which COP becomes too low because of extreme temperatures, causing a less efficient performance of the pump. Moreover, during the moments in which the electric energy produced by the PV is higher than the users’ demand, this surplus energy can be used by the heat pump to fulfill the thermal load. In this case, as opposed to the first scenario, the utilization of the heat pump implies a part of physical collective self-consumption, which is not incentivized as the virtual one. The analysis of the two scenarios is made not only in terms of energy consumption, but also from an economic point of view. In this context, the benefits given by the introduction of the heat pump are shown, thanks to the reduction of fuel consumption, that generates a positive effect both in terms of savings and environmental impact. Moreover, an investment analysis is performed, focusing the attention on various indicators, including payback time and internal rate of return. The PVGIS data set is used to download the temperature and irradiance data for all the points on the Italian map (with a distance of 2.5 km between each point). Thanks to these data, the simulation is performed on each point, but always using the same reference building. The results are then represented in spatial form, on a map, using the QGIS software.