Cost Optimal Analysis of Positive Energy Buildings

This paper describes the cost optimal calculation method for the techno-economic assessment of Positive-Energy-Buildings (PEBs) and applies this evaluation framework to two case studies in different climate zones. The approach is based on the EU supplementing guide-line 2012/C 115/01 and compares global costs and net primary energy demand of different energy technology packages. The case studies are residential buildings located in Valladolid, Spain (Mediterranean climate) and Helsinki/Kalasatama, Finland (Nordic climate). The results of the analysis reveals that not all PEB technologies are cost optimal and reduce global costs with current energy prices. Several factors affect the cost-effectiveness of the technologies, such as the shape of the building, the climate zone and the overall technological system in which they operate. Furthermore, results are very sensitive to calculation parameters such as electricity prices, discount rate and calculation period. The cost optimal analysis of case stud-ies in different climate zones indicates that PV and a change of the heating system are in most cases cost optimal technology solutions that reduce net primary energy demand and global costs. Lessons learned from this research can contribute to the definition of comprehensive evaluation frameworks aimed at optimizing, disseminating and replicating PEBs in Europe.