IEA SHC Task 54: Price reduction

Up to 2010 the market growth rates of the solar thermal industry were more than 10%. Since then, the growth rates have been declining amounting to just 4% in 2016/17. Furthermore, a significant shift from pumped hot water and space heating systems in moderate climate zones (e.g., middle Europe) to more simple, non-pumped hot water collector system in emerging markets was discernible. Experts are agreeing, that anew push for the solar thermal market can be achieved just by significant reductions of the overall, final customer costs. Hence, the main objective of IEA SHC Task 54 was to elaborate and evaluate measures for price reductions of solar thermal systems.

The working programme of Task 54 consisted of 4 subtasks with focus on market success factors and cost analysis (Subtask A), system design, installation, operation and maintenance (Subtask B), cost-efficient materials, production processes and components (Subtask C) and information, dissemination and stakeholder involvement (Subtask D). Austria took a leading role being responsible for Subtask C. Of importance for Task 54, was the successful implementation of associated, collaborative research projects (e.g., SolPol-4/5). JKU-IPMT, AEE INTEC and UIBK contributed as scientific partners to Task 54, while Sunlumo was inovolved as Austrian company partner. Expertise from different fields such as solar thermal and polymer technology and science was provided. Austria contributed to all Subtasks. However, the main focus of the Austrian acitvities was on pumped and non-pumped solar thermal systems based on adequate design (e.g., full overheating protection).

In Task 54, a tool for the assessment of levelized costs of heat (LCOH) was implemented and used to evaluate reference systems and cost-optimized systems. By adequate design, performance increase and the use of standardized components a 40% reduction of the solar LCOH values was achieved for hot water and combisystems in middle Europe based on conventional materials (i.e., metals and glass) for the collector. In particular, this cost reduction was possible by all-polymeric piping of the overheating protected solar loop, which allows in contrast to copper pipings for ease of installation and less material costs. Considering the auxiliary heating system, the overall LCOH values could be reduced just by up to 5%. The investigations clearly revealed, that the LCOH values are significantly lower for solar thermal hot water preapration in multi-family houses than for installations in single-family houses. The costs of solar thermal systems for hot water preparation in warm and tropical climate zones, the emerging markets, can be significantly reduced by material transformation from metal/glass to polymers. All-polymeric pumped systems (s. Figure) exhibit similar LCOH values compared to market dominating thermosyphon systems. For integrated storage collector systems a cost reduction by 40% is possible by substituion of metals with limited corrosion resistance by plastics. Ultra-low-cost-systems with final customer prices of about 100$ (excl. installation) are feasible by simple collectors and storages in polymer film or membrane design.

Australia, Austria, China, Denmark, Germany, France, Italy, Netherlands, Norway, Switzerland

Institute of Polymeric Materials and Testing
Johannes Kepler University Linz
Ao. Univ.-Prof. Dipl.-Ing. Dr.mont. Gernot Wallner
Altenberger Straße 69
4040 Linz, Austria
E-Mail: gernot.wallner@jku.at