Life Cycle Costs and Environmental Life Cycle Analysis of Solar Water Heaters in Greece

摘要

Usually, the solar water heater (SWH) systems use the sun to heat a fluid, either water or a heat transfer fluid, such as water-glycol antifreeze mixture, in flat collectors generally mounted on the roof of residential or industrial buildings. The heated fluid is then stored in a tank similar to a convectional gas or electric water tank. Some systems use an electronic pump to circulate the fluid through collectors. In this paper, the basics of solar water heaters (SWH) life cycle costs analysis are discussed and the most popular types for Greece are examined. Life cycle costs are formed and the possibilities for reducing them are discussed. Specifically, for the cost analysis, a life cycle approach, in which the various costs are estimated annually, is considered. The analysis is performed in order to obtain the total cost (or life cycle cost) and the life cycle savings of the system. Moreover, the environmental impacts derive from the life cycle of the systems examined are analyzed and assessed with the application of relative software. In order to examine various impact categories such as global warming, ozone layer depletion, ecotoxicity and so forth, the IMPACT2002+ method is applied. In that aspect the life cycle stages, processes and materials that significantly affect the system examined are identified whereas amelioration actions and redesign "hot spots" are further discussed. The fact that both the economical and environmental pillars of sustainability are examined in this study provides a holistic approach regarding different aspects of solar water heaters life cycle. The main aspect that can be concluded is that solar water heater systems are efficient, cost effective and environmental friendly. The reduction of greenhouse gasses is the main advantage of solar energy. Therefore, solar water heater systems should be employed whenever possible in order to achieve a sustainable future.