The role of photovoltaic technology in achieving net zero energy target in residential buildings

The construction sector plays a pivotal role in reducing carbon emissions, facilitating the transition to renewable energy and promoting sustainable development. In the European Union, where decarbonization strategies are currently proving most incisive, legislative measures such as the Energy Performance of Buildings Directive (EPBD) have catalyzed a marked increase in the prevalence of energy-efficient buildings. In terms of decarbonization, such efforts can be achieved by massively applying Renewable Energy Sources (RES) both in new buildings as well as in existing ones, which represent the majority of the EU building stock. For such reasons, Building-Integrated/Applied Photovoltaic (BIPV/BAPV) systems offer a promising avenue for providing clean energy to the building sector. Nonetheless, despite their potential, the practical implementation of these systems on buildings faces feasibility constraints, mainly due to the limitation of the available installation surface.

In such a framework, this study conducts a comprehensive evaluation of BIPV/BAPV installations potential to fulfill the electricity needs of residential buildings (i.e. achieve the net zero energy target), with a particular focus on multi-family structures within the European contest. A reference high-performance building, already assessed by the authors and therefore very well documented, was used as a test bed through detailed dynamic energy simulations. According to obtained results, the net zero energy target can be achieved for energy-efficient buildings with up to 3 and 5 storeys, in Nordic and Mediterranean climatic conditions, respectively. Assuming instead reference maximum consumption thresholds (resulting in higher energy consumption), achievable results are more restrictive, since zero-energy buildings are limited to a maximum of less than 2 storeys in Nordic climates and 3 in Mediterranean climates.

In this particular historical period, the outlined results take on considerable relevance, as the highlighted feasibility limitations could jeopardise the implementation of zero emission targets, but they can also be used to properly orient energy policies under development.