Life cycle assessment of an allpolymeric ultralowcost nonpumped solar thermal collector system for hot water preparation

Solar thermal systems are of high relevance and interest in the supply of low-temperature heat for different purposes. Especially, hot water systems are dominating the solar-thermal market with non-pumped systems gaining more and more importance. In recent years attempts have been made to open up a mass market for solar thermal energy and thereby promote the use of renewable energies with novel, more cost-effective materials, and production processes. For emerging markets in developing countries, the competitors of solar thermal systems are in the main wood stoves, gas- and electric boilers or ‘cheap’ Chinese thermosiphon systems. These water heaters either have a negative environmental impact, are too expensive in costs of purchase or too expensive in costs of operation or have a rather short product lifetime. To address these markets, it is vital to provide an affordable ultra-low-cost system with high reliability and low technology. A system suitable for compact distribution and easy installation. To put it in a nutshell, this system must be a very simple thermosiphon system based on cheap polymeric membrane technology for both, the absorber and the storage. The main objective of this paper is to assess a novel all-polymeric ultra-low-cost non-pumped solar thermal system for hot water preparation as to its life cycle metrics. Finally, the evaluated ecological impact is compared with the impact of the main competitors. For the assessment, the Eco Audit Tool of CES Selector by Ashby et al. and Granta Design is used.