Contradictions of low-emission nZEB buildings

Abstract

Based on the EPBD 2010 directive and the mandated method of cost-optimum calculation the forthcoming national regulations require “nearly zero energy buildings” which have high energy performance, significant share of renewables in covering the low energy need and harmonizing the requirement system and the cost-optimum all over in Europe. Known intention of the EU Member States as well as some research reports create the impression that predominant use of biomass in the forthcoming years will be the right way to fulfil the above requirements of nearly zero energy buildings. Taking advantage of regulations in many Member States, the amount of yearly primary energy demand is favourably influenced by the low primary energy conversion factor determined by the very states; besides the delivered energy does not decrease. The CO2 neutrality of biomass is not real. It is true that the emission of gas firing far exceeds that of wood firing, but emissions from the production of natural gas might be lower than that of the production of certain wood products. Overall, the lifecycle-based emission of biomass firing for the most converted fuels is already significant. In the case of wood combustion, the local pollutant emissions, which occur in cities, are significant, while the CO2 constraint take place in the forests.