The Solar Research of the German Aerospace Center (DLR) aims to develop environmentally and climate-friendly energy systems that convert solar radiation into usable energy. The focus is on reducing the cost and improving the performance of components and systems applied in solar thermal power plants.
In particular, this includes work on components for parabolic and tower plants based on DLR's own research platforms , new measuring and qualification technologies and simulation tools. Beyond that, scientists are also looking for new fields in which solar technology might be applied. Another area of growing interest is that of solar chemistry and the development of relevant process technology which is hoped to be ready for industrial application in the medium term.
The DLR Solar Research Institute’s scientific and administrative employees are based at DLR’s Head Office in Cologne and at its Stuttgart and Jülich sites, as well as at Europe’s largest test facility for concentrated solar technology, the Plataforma Solar de Almería, which is owned by DLR’s Spanish research partner CIEMAT. DLR’s solar research facilities are unique in Europe, possessing highly sophisticated equipment as well as excellent scientific competence. Its position as a top co-operation partner of industry has resulted in a share of more than 60 percent in third-party funding.
Fundamental scientific research is mainly funded with grants from the Programme-Oriented Funding Programme of the Helmholtz Association (HGF). Under HGF’s Renewable Energies Programme, DLR together with other research institutions is hoping to unlock new knowledge whereby a major technology breakthrough might become possible within the medium term.
The new programme for the 2015 – 2019 period aims mainly at the development of new heat transfer fluids which are high-temperature resistant while at the same time having good heat transfer and heat storage properties. Investigations in this context focus on molten salts and ceramic particles. On that basis, systems with a markedly higher efficiency, lower cost and more flexible operational characteristics could be developed, which would constitute a genuine technological breakthrough.
The second focus will be on quantifying the impact of environmental conditions on the efficiency and service life of solar power plants operating on a desert site.
The third proposal relates to further research into the utilisation of solar radiation in chemical processes, the aim being to produce hydrogen or synthetic gas from water and CO2. This research intends to improve our understanding of the underlying reaction mechanisms, so that solar reactors can be designed to store solar energy with a higher degree of efficiency.
In addition to the research funded by HGF grants, DLR researchers also team up with industry partners to work on mainly application-oriented research and development assignments with funding from external sources.
This includes developing methods of component qualification with regard to efficiency and service life. The results will form the basis for the development of standards and requirements for components and systems used in solar thermal power stations. Together with external partners, scientists especially work on next- generation parabolic-trough power plants using direct solar steam and molten salts. Large-scale tests are currently being prepared. These efforts will focus in particular on the development and qualification of adapted collector field components which will produce higher temperatures, as well as on the development and demonstration of improved integration concepts, operating strategies and control algorithms.
Tower technology involves the development and demonstration of enclosed high-temperature receivers which feed solar energy into highly efficient combined-cycle power plants. Having an overall solar efficiency of around 30 percent, these systems represent the technology with the maximum solar efficiency conceivable at this stage, thus offering considerable cost reduction potential. Moreover, DLR is assisting industry with the development of low-cost heliostats, which are needed for concentrating the incoming sunlight on to the receiver.
All of DLR’s solar research activities have now been merged under the roof of the DLR Institute of Solar Research which was founded in 2011. They are closely tied to the work of the DLR Institute of Technical Thermodynamics in matters concerning energy storage, electrolysis and fuel cells. Scientists work, for example, on the development and qualification of low-cost thermal energy storage systems for solar power plants. Recent developments in the area of renewable energy applications and an extensive new analysis of hybrid solar-power plant processes have led to renewed investigations into energy storage for solar thermal power plants. Computer models based on a one-year operating history have shown that thermal storage will considerably increase the economic efficiency of solar power generation.