ABSTRACT
Pit Thermal Energy Storages sealed with geomembranes have proven to be vital applications for long term storage of solar thermal energy or excess heat in large volumes at affordable costs. Energy content and its utilization depends on the system integration, so does the temperature profile, which impacts the liner material lifetime. During the transformation of energy systems a thorough demand for energy storage can be expected in the future. The project in Høje Taastrup vastly increases scope of functions as permanent high temperatures (≥ 90°C) enable more advanced operation strategies with additional measurable economic outcomes for operators. For lifetime prediction of liner materials, a methodological approach was implemented based on micro-specimen. Due to the reduction of specimen thickness an acceleration factor of up to 20 was achieved. The best performing novel PP-HTR liner material revealed a predicted lifetime of up to 35 years at a temperature loading profile ranging from 60 – 90°C.
