Obligatory versus voluntary energy audits: are there differences in quality?

Directive 2012/27/UE of the European Parliament has created a new motivation for energy audits: the avoidance of penalties. According to this directive, large companies in all EU member states must carry out energy audits at least every four years. Does this obligation affect the quality of energy audits? We hypothesize that voluntary audits, in comparison to mandatory audits, have a higher quality level in terms of a higher investment in energy efficiency measures. While mandatory audits must always take the entire company into account, voluntary energy audits allow companies to focus on the most promising business or process areas. The energy balance limits can also be drawn more focused. The auditor can also be selected according to specific professional qualifications. As a methodology, we first define quality criteria for energy audits based on the energy efficiency measures determined. Important factors are the adoption rate, the calculated energy savings and the consideration of non-energy benefits in the calculation. The validation of the collected quality criteria is carried out by a comparison with the results of already existing research work. In an empirical study, we then compare data from audits of both types that have already been carried out with regard to the quality characteristics found. Via a database with 1,692 energy audits conducted in Germany in the years 2014-2016, we can draw up detailed comparisons of the energy balances and, in particular, of the measures calculated. This enables clear conclusions to be drawn about the differences in quality between the different program types.