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Polymeric collectors have been exposed on outdoor testing sites in three distinct climatic locations and the climatic loads and collector temperatures have been monitored by the minute. The obtained data was analyzed with focus on the frequency and extend of the thermal loads, which the different components of the collector were exposed to. As a result this data can be correlated to accelerated aging tests.

As part of the Shagaya Renewable Energy Master Plan in Kuwait, the presented study describes the methodology developed and applied for the optimization of the technology mix for a 2̊GW, 1002km2 renewable energy park. Scenarios with different focuses for the technology mix were developed, selecting from 14 technology options (three wind, five PV and six CSP) and emphasizing either high peak load supply, high overall annual electricity production or low levelized cost of electricity. An optimization procedure that uses a general pattern search algorithm implemented in the software GenOpt was used to maximize a score calculated from eight criteria. These were determined in a social-techno-economic evaluation, which included performance simulations of every technology option for the allocated site in Kuwait. Besides the available land area, the capacity credit of the installed technology mix was included as an additional boundary condition. 2010 was selected as base year since it was the most recent year for which both high quality meteorological and electricity demand data was available. The results for all considered scenarios are presented in this paper, with the one that was chosen as final result of the master plan comprising 136̊MW wind power, 614̊MW of PV and 1250̊MW of CSP. Furthermore, the study showed that thermal storage is indispensable to serve peak demand hours and a diverse technology mix is important to achieve a high capacity credit.

In the process of improving the performance of concentrating solar collectors a variety of reflector materials are undergoing development. To allow comparable performance predictions, precise and replicable measuring methods are needed. In this paper we propose a measurement method and set-up (VLABS: very-low-angle beam spread) to determine the specular reflectance for variable angular acceptance. Our measurement set-up and method VLABS is advanced in measurement accuracy and speed, it gives as a result the specular reflectance for variable acceptance angles with an angular resolution of 0.03 mrad. We show exemplary results for a glass and an aluminum reflector and discuss the impact of acceptance angles up to 33 mrad on measured reflectance values at different wavelengths.

In the German national research and development project “HeizSolar” the building concept of Solar-Active-Housesis analyzed. The concept allows for a high fraction of solar thermal energyof more than 50% of the total heat supply. Within the project nine existing buildings have been monitored since the beginning of the heating period of 2011. The technology applied for this kind of supply concept has been introduced in [1,2]. Based on the data obtained from the in-situ monitoring, typical operation conditions have been identified and analyzed in [3]. The measured datawas also used to derive parameters to calibratea dynamic system simulation model for Solar-Active-Houses[4]. Theelaborated model focuses on the performance of the solar thermal collector as well as the solar circuit. What is more, the dynamic interaction between the solar thermal heat generator and the auxiliary heating systems as well as the heat distribution system are incorporated in detail. Finally the diffuse heat flux resulting of the integration of large hot water storage tanks into the building envelope is implemented to the model. This model is applied in the following to analyze the general thermal behavior of the supply concept and to derive optimization potentials. In detail the systems performance in regard to different types of heat transferal systems for space heating is demonstrated. Also the dimensioning in regard to the key parameters of collector area and the thermal capacity of the storage system consisting of a hot water storage tankare stated.

Heat transformation based on adsorption/desorption of water in microporous adsorbents has been considered for the application as adsorption chiller (ACS), adsorption heat pump (AHP) or thermochemical storage (TCS) since the 1980s. Unfortunately, most of the available adsorbents like zeolites were not optimized for the use in these processes as they originally had been developed for gas separation or catalysis processes. Within the last decade, intensive research on adsorbents yielded in improved and very promising new sorption materials with an enhanced adsorption capacity. This work gives a broad overview on current developments on materials including the new class of metal-organic frameworks for the use in adsorption processes for heat storage and transformation.

Transparent facade collectors can provide solar heating and cooling and lead to primary energy savings even compared to an opaque wall. They can be simulated with a detailed physical model based on laboratory measurements. The demonstration installation in Ljubljana will provide extensive measurement data of transparent facade collectors in an outdoor environment. This allows a comparison with simulations performed with the model validated by laboratory measurements. This paper presents the demonstration installation and the measurement system, which are based on the new modelling abilities and focused on the outdoor validation of such models.

Within the Aktifas project, a road map is being developed for research and development of facade-integrated solar thermal systems. The road map is based on an analysis of the barriers for facade-integrated solar thermal systems as well as a market overview of existing components. This paper presents the methodology for creating the road map as well as first results. The final road map will be published on http://bit.ly/Z0hkso at the beginning of 2015.

Desert areas are noteworthy for solar system installation due to high yearly global irradiance. These arid regions bear extreme conditions for surfaces, like glazing and mirrors, of solar thermal systems. Surfaces are targets for soiling because of wind and high dust loads. Soiling is causing a decrease in transmittance that limits the overall performance. At a certain level depending on surface properties, like functionality and their reliability, is surface material soiling-prone. For surface qualification is a reproducible soiling test needed. An in-house developed artificial soiling device achieves this purpose. Realistic dust deposition is used to test the functionality and properties of surfaces for application in arid regions. The parameter study points out the connection between properties of surfaces and the adhesion behavior of real dust. Soiled surfaces are analyzed by by spectroscopic (FT-IR) and gravimetric measurements.