Energy balance and photovoltaic integration in positive energy buildings. Design and performance in built office case studies

Abstract

Solar design will be reshaping the architecture as one way to address the global climate crisis and the reduction of fossil fuel consumption. This paper analyses the current definition of Positive Energy Building (PEB) and a selection of both NZEB and PEB built projects with real monitored data, discussing their design features and potential for achieving positive energy balance. The research aims to assess an optimal ratio between PV area in both roof and façade, net floor building area and achieved self-sufficiency ratios in office buildings. The study shows that most of the buildings’ PV systems have an area equal to 10-20% of the total building’s net floor area. Buildings that have PV to area ratio from 13 to 20% are self-sufficient from 100 to 150%. PV installation in the façades results decisive for reaching positive energy balance. The relation of the PV system installed on the façade to PV system on the roof is from 50 to 57 % for the studied buildings. Buildings located in sites with higher GHI tend to have lower PV area ratios and a ratio of 20% or more is valid for all the studied sites to achieve electrical energy self-sufficiency.