Motivation and aims

 
During the recent years, larger solar thermal plants are being developed, either for novel applications, like industrial process heat, drying, air conditioning and cooling applications or to reach higher solar fractions for domestic applications and district heating plants. Moreover, a new component design for the collector and storage components are needed to reach higher temperatures in some of the novel applications, including thermal-electric solar applications (PV/T). Therewith, solar heating plants became more and more complex due to the larger number of components interacting in the heating systems. Especially the smooth interaction with conventional heating systems was shown to play an important role on the overall system efficiency, which strongly depends on the temperature level in the system. The system control is often extremely complex and parameter settings need to be identified with more sophisticated methods than for conventional solar heating applications. Additionally, new problems arise due to very high temperatures that appear when no or little heat is needed (stagnation of the solar heating plant).

 Each of the ten PhD projects address these challenges from a different point of view.

 The components of the solar heating system itself, as well as reference conditions (like load profiles, building standards, etc.), conventional subsystems (like auxiliary heating systems), and novel subsystems (like sorption cooling systems) are investigated for different applications. The SolNet project is concerned with different components, system investigations and advanced applications of solar heating systems.

The topics of the PhD projects are grouped around the aims

• to reach high solar fractions in domestic applications (solar combisystems), with a focus on the auxiliary heating system and parameter optimization
• to further develop components of solar heating systems (solar collectors and water storage tanks) for various novel applications
• to develop solar cooling applications and
• to guarantee the thermal performance of solar heating systems for various applications in a long term with novel system monitoring methods