In this section we provide an overview of research activities currently underway at the SPF institute. These projects are in principle open to the participation from representatives from the economic and research sectors. This allows you to benefit from the competence of SPF close at hand.
The stratification efficiency of heat storages has a decisive impact on the energetic efficiency of solar thermal systems as well as of heat pumps. In this project, a representative key figure for stratification efficiency and a cost-efficient test procedure for its determination are developed for combi-storages that provide space heat and domestic hot water. The procedure is applied to combi-storages of different manufacturers, and the results are compared with each other. In addition to this, CFD simulations are carried out for the determination of the impact of direct horizontal storage inlets on the stratification of the storage. Selected stratification experiments are also validated with measurements the laboratory. At the end of the project, recommendations are given for the geometry and maximum volume flow rate at which direct horizontal inlets can be used without disturbing an already existing stratification in the storage. This project receives funding from the Swiss Federal Office of Energy SFOE.
The EU project MacSheep is coordinated by the Institut für Solartechnik SPF and deals with the development of heating systems which combine solar thermal energy with heat pump technologies. The ambitious goal is to reach a reduction of 25% of the electric energy use of those systems in comparison to the state of the art of 2011/2012 within the four years of the project. These research and development activities receive funding from the Seventh Framework Programme of the European Union under grant no. 282825. The project start was in January 2012. More information can be found on the project website.
The combination of solar thermal systems with heat pumps is used increasingly for space heating and domestic hot water preparation in the building sector. Both technologies are considered to be key-technologies for the abatement of green house gas emissions. The combination of heat pumps with solar thermal heat increases the system’s efficiency and thus the electricity demand. Possibilities for the combination are versatile, and the question arises under which circumstances it is advantageous to use solar thermal collectors also for providing heat for the evaporator of the heat pump.
SPF is carrying out research in this field in the framework of the IEA-SHC Task 44 in international cooperation with other institutes and the industry. Our main focus is the development and evaluation of new system concepts with the aid of computer simulations and laboratory testing with the well-proven Concise Cycle Test.
Final Report (English)
Solare Kombispeicher und Wärmepumpe – Empfehlungen zur System-Integration
Stockage Combiné et pompe à chaleur - Recommandations pour l’intégration dans le système
Accumulatore combinato solare e pompa di calore - Consigli per l’integrazione in sistemi
A fast-growing market for solar thermal systems combined with the constantly increasing prices of the relevant commodities urged for a reflection to be made on the existing architecture of solar systems. In this context the polymers, which have been considered of little importance so far, may take on a key role in the future. When speaking of large volumes these particularly cost-effective production methods seem to be posing interesting cost-saving potentials.
SPF is carrying out research in this field within the framework of the IEA-SHC Task 39 in close international cooperation with other research agencies and industry. Our main focus is on designing innovative collectors and carrying out durability tests on the polymers employed.
Increasing requirements for building cooling (not only in the summertime) and the consequent overload of electrical networks is turning into a major challenge. In this context solar cooling in general and solar thermal cooling in particular may make for an attractive variant in the reduction of required electrical power.
The SPF institute is actively engaged in this field and contributes to development within the framework of the IEA SHC Task 38 “Solar Air Conditioning and Refrigeration”. A technology involving the release of heat in a hybrid cooler can be used as an alternative to open cooling towers in the medium-temperature range. It is being tested and improved with the 10kW LiBr-H2O STATC laboratory system. System simulations with Polysun 5 are validated with measurement results.