The Primary Energy Factors play a central role in European 2020 targets achievement

The primary energy factors are numerical coefficients that weigh the different energy carriers, comparing them to the corresponding energy sources. The 2010/31/EU Directive establishes that the building energy performance should be expressed by a primary energy index. The analysis of the values currently employed in the European Countries shows that the performance assessment results are highly dependent from these values. The aim of the paper is to show that primary energy factors can play a central role for leading the building sector towards the European 2020 targets achievement. Starting from their determination it is possible to direct the choice among different energy carriers, as well as to rule the competition between renewable and fossil energy sources. Moreover the PEF values diversification for the imported or exported energy allows to advantage the distributed generation compared with the power generation, and the on-site produced energy consume compared with the input to grid.