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In this study, the energy, exergy, exergoeconomic and exergoenvironmental (4E) analyses of a cogeneration system that combines photovoltaic thermal panels (PV/T), evacuated tube solar collectors, an organic Rankine cycle (ORC) and energy storage systems are performed. The cogeneration model is built to meet the load demand of independent houses in remote areas and avoids excessive consumption of traditional energy and environmental pollution. Here, the exergoenvironmental analysis adopts the Eco-indicator-99 method and the all life cycle assessment method is used to calculate the environmental impact of each component. Two comparative studies are conducted to the 4E analyses. The first one compares the comprehensive performance of the battery storage and hydrogen production for energy storage. The results indicate that the cogeneration system using both batteries and hydrogen production for energy storage has the best overall performance. According the exergoeconomic and exergoenvironmental analyses, its environmental impact is 23.6% lower than the cogeneration system using batteries alone and the PV/T can be fully utilized. In addition, the total cost rate is 6.2% lower than the cogeneration system using hydrogen production alone. The second case investigates the effect of adding the evacuated tube solar collectors between the PV/T and ORC on the cogeneration system. The analysis results demonstrate that the evacuated tube solar collectors can increase the heat source temperature of the ORC to increase the power generation of the ORC by 37.14%; however, the total cost rate of the cogeneration system increases by 3.7% and the environmental impact rate increases by 19.8%.

According to predicted changes in climate, waterlogging events may occur more frequently in the future during autumn and winter at high latitudes of the Northern Hemisphere. If excess soil water coincides with the process of cold acclimation for plants, winter survival may potentially be affected. The effects of waterlogging during cold acclimation on stomatal aperture, relative water content, photochemical activity of photosystem II, freezing tolerance and plant regrowth after freezing were compared for two prehardened overwintering forage grasses, Lolium perenne and Festuca pratensis. The experiment was performed to test the hypothesis that changes in photochemical activity initiated by waterlogging-triggered modifications in the stomatal aperture contribute to changes in freezing tolerance. Principal component analysis showed that waterlogging activated different adaptive strategies in the two species studied. The increased freezing tolerance of F. pratensis was associated with increased photochemical activity connected with stomatal opening, whereas freezing tolerance of L. perenne was associated with a decrease in stomatal aperture. In conclusion, waterlogging-triggered stomatal behavior contributed to the efficiency of the cold acclimation process in L. perenne and F. pratensis.

Abstract This paper presents a cross-country benchmarking study of natural gas distribution to final consumers and compares two samples of companies in Italy and Ukraine. A 2-stage DEA procedure calculating efficiency of gas providers and identifying critical context factors and policy issues that affect it is implemented. Both countries are low performing in terms of operators’ technical and scale efficiency and there is room to design more efficient market configurations. Some issues need attention to develop an effective gas market policy: a) search for efficiency requires accurate investigation of its main drivers that depend on context factors; b) while greater efficiency is necessary to reduce cost and increase service quality, at different stages of progress of the reform process other goals may be more important; c) gas industry reform process should be planned adopting a systemic perspective as its development does not remain confined to the sector, but implies changes in the whole country economy, particularly when the gas market is of primary relevance to the economy; d) a more comprehensive package of reforms may be necessary to make gas market reform successful; e) even though the gas market reform is an economic process, it has unavoidably social and political implications.