Considering environmental issues such as greenhouse gas emissions associated with climate change and the depletion of fossil fuels, one of the possible solutions is the use of renewable energy sources. Wind energy is one of the most competitive and resilient energy sources in the world, which can play an important role in accelerating the global transition to green energy. The purpose of this study is to evaluate the allocative efficiency of 47 offshore wind energy companies in 9 European countries using the input-oriented BCC DEA model. The basic hypothesis is that by evaluating the relative efficiency of offshore wind energy companies in European countries, it is possible to determine a correlation between the results of efficiency between the two observed periods with slight deviations. The empirical results show no significant correlation between the score of relative efficiency and the country where the offshore wind energy company is located. On the other hand, the results are consistent with the basic hypothesis of this study. From the management perspective, significant improvements in all financial variables, i.e., tangible fixed assets, cash and cash equivalents, and current assets, are required to achieve relative efficiency. The model variables refer to the economic characteristics of offshore wind energy companies, indicating that only allocative efficiency was analysed, which is in contrast to previous studies.

The Croatian economy performs unfavorably in terms of the impact of production on wastewater discharges, which is particularly pronounced in the industrial sectors. Each unit of gross industrial value added produced in Croatia generates significantly more wastewater discharges than in most European countries with a similar level of economic development. Moreover, in 2020, only 26.9% of the total industrial wastewater discharges of the Croatian economy were treated, while 76.2% of the total industrial wastewater discharges were directly discharged into the environment. Since most of the industrial production in the Croatian economy is destined to meet the intermediate needs of other sectors, policy makers in Croatia must take into account that the level of industrial wastewater discharges is also influenced by the production level of sectors that depend on the intermediate products of wastewater-intensive industries. For this reason, we developed a wastewater extended input–output model of the Croatian economy to determine and analyze the impact of intersectoral linkages in Croatian production systems on the amount of untreated wastewater discharges. The results of the study show that wastewater flows in the Croatian economy are largely generated by the processes of production and consumption of intermediate products from the chemical and petroleum refining sectors, which also account for the largest share of the calculated wastewater footprint of total Croatian production. In light of the emerging empirical evidence, it can be concluded that targeting market-based and regulation-based measures at wastewater-intensive producers is not sufficient to reduce the relatively high level of untreated wastewater discharges in the Croatian economy. There is also a need for appropriate integrated policy measures in sectors that have a large wastewater footprint due to their established supply chains.