Storage technology based on solid media heated in direct contact—so-called regenerators—is well suited to promote the market introduction of solar central receiver plants with air receivers. However, starting from existing technologies, several design issues need to be addressed. A test campaign was performed at the Solar Power Tower Jülich, an experimental central receiver plant, to experimentally verify the functionality and to quantify the performance of the plant’s storage subsystem. To this end, a gas burner used during commissioning of the plant, was reactivated and used to run a series of operation sequences. Computer simulations have been set up and applied to retrace the storage behavior to confirm the validity of the underlying models and to gain further insight into the relevant phenomena. The test results confirm the full functionality of the storage subsystem, the ability to perform cycling at high discharge heat rates and relatively low heat losses, supporting the view that the technology represents a promising basis for up-scaled implementations. Measurement data and simulation results are in good agreement, confirming the maturity of existing design tools.

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a b s t r a c tA selection of granular natural and ceramic materials has been experimentally characterized with regard to their application as heat transfer and storage media in concentrating solar power plants. Thermophysical, thermomechanical, tribological and rheological measurements have been conducted in order to identify the most suitable candidates for this dynamic high temperature operation. Ceramic materials are found to comprise some advantages, but natural products offer a considerably more economic solution. Thermal bulk conductivity is found to be only marginally affected by the solid's thermal conductivity, while specific heat is the same for all solids. Ceramics entirely withstand thermal cycling, while quartzcontaining materials are prone to severe degradation. Most materials are found to attain a saturated state of attrition while being sheared under load, wherein quartz sand offers the lowest mass fraction of debris at saturation level. In the investigated grain size range, all materials show good flowability. The generation of debris requires consideration in the design of the CSP storage components.

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