Comprehensive analysis of the incidence of glazed components and PV system degradation on the achievement of nearly zero energy balance under extreme events and climate changes

The resilience of the nearly zero energy buildings under the expected climate changes and the extreme events is a key aspect to be taken into account for new and refurbishment designs. The paper introduces a numerical approach that allows evaluating the influence of two critical aspects: the impact of glazed components on the building energy needs and the weight of PV modules degradation on the energy balance. It is based on reliable weather data for the simulation of current conditions, extreme years, medium-term and long-term climatic projections. The results for the proposed case study indicate that extreme events could cause great variations in the energy performance; in the case of an extreme cold year, the heating request would increase until +16 % meanwhile in the case of an extreme hot year, the cooling energy need would rise up to +20 %. A future transition towards strongly cooling dominated climate is remarkable: the energy demand will increase of +35 % in medium-term and + 48 % in the long-term scenario but the contemporaneity between the energy demand and in-situ production should allow balancing the effects of photovoltaic degradation. Indeed, self-consumption would increase by +3.8 % in the medium term and by +7.3 % in the long term scenario meanwhile the exported energy will decrease respectively of −20.3 % and −18.4 %. Moreover, the adoption of selective or thermochromics windows give worst performance with increment of the cooling demand until +59 % and +48 % in the medium-term scenario with the increment of self-consumption of around +2 %; in this case, the imported electricity will reduce of −2 % with selective glasses and increase of +1 %with dynamic solution.