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Abstract: The technical and environmental performance of a solar water heater (SWH) is examined using the method of life cycle assessment (LCA). The present LCA study quantifies the environmental benefits of the installation of a SWH with electricity as auxiliary for domestic use in the city of Thessaloniki. Solar thermal heating produces no emissions during operation but some small levels of emissions are produced during the manufacture and installation of components and systems. This work examines the manufacturing stages of the SWH and records resource consumption and waste streams to the environment. The system boundary includes the production of raw materials such as steel, glass, copper, aluminium, glass fibber and polyurethane insulators, the manufacturing of the various parts of the SWH such as the solar collector and the heat storage tank, and finally the assembly process. The functional unit chosen is 1 MW of produced hot water. The environmental impacts taken into consideration in the study, are the greenhouse effect, ozone depletion, acidification, eutrophication, heavy metals, carcinogens, winter smog and summer smog. The system can provide 1702 kWh year−1 and the solar contribution is 58.5%. The financial characteristics of the system investigated give life cycle savings equal to 4280.0 € and pay-back time equal to 5 years. [Copyright &y& Elsevier]

Abstract: The energy fuels used for in the Greek transport sector are made up of gasoline consumed by automobiles, diesel oil consumed by taxis, trucks, maritime transport and railroads, and jet fuel used in the aircrafts. All these fuels are hydrocarbons that emit great amounts of CO2 which has a major impact in the global warming phenomenon. The issues relating to climate change, the soaring energy prices, and the uncertainty of future oil supplies, have created a strong interest in alternative transportation fuels. During the past decade biofuels in the form of blended gasoline and biodiesel have begun to find place in energy economy. The Greek car market shows a remarkably low rate in the penetration of biodiesel compared to the average European Union market. This work compares the environmental impacts of the use of gasoline, diesel and biodiesel in Greece using as a tool for the comparison the Life Cycle Assessment (LCA) methodology. The environmental impacts taken into consideration include: organic respiratory effects, inorganic respiratory effects, fossil fuels, acidification – eutrophication, greenhouse effect, ecotoxicity and carginogenic effects. From the environmental point of view, biodiesel appears attractive since its use results in significant reductions of GHG emissions in comparison to gasoline and diesel. It also has lower well-to-wheel emissions of methane. However, the use of biodiesel as transportation fuel increases emissions of PM10, nitrous oxide, nitrogen oxides (NO x ) as well as nutrients such as nitrogen and phosphorous; the latter are the main agents for eutrophication. This study can be considered as an opportunity for further research and evaluate the available options for a sustainable transportation system planning in Greece. [Copyright &y& Elsevier]

Abstract: Transport is of fundamental importance to human society, providing mobility and facilitating industry and trade. Nevertheless there are also many environmental impacts; thus it is crucial that transportation planning is carried out in a sustainable manner meeting optimum travel needs, promote economic prosperity and environmental preservation. In assessing the efficiency of transportation, exergy analysis is an effective tool. This work presents an energy and exergy utilization assessment for the transportation sector of Greece taking into account the sectoral energy and exergy flows for the period over 1980–2003. Energy and exergy analyses are conducted for the four subsectors of the Greek transport sector, namely highways, railways, marine and civil aviation. The road subsector appears to be the most efficient in comparison to the other subsectors for the years between 1980 and 2003. It is believed that the exergy analysis presented here provides insights into the transport energy use and could assist in the planning of an efficient transport system. [Copyright &y& Elsevier]