L-Sol
The L-Sol project is investigating a heating system that combines heat pumps with hybrid collectors (PVT). These use both air (L) and solar heat (Sol) to generate energy, which is more efficient than using air alone as a heat source. This generates electricity and heat at the same time.
Challenges
Energy concepts for new buildings and renovations are a major challenge in the building energy sector today, especially for single-family homes. For apartment buildings, there are convincing concepts with heat pumps, such as geothermal probes or E-Tank (insulated geothermal heat register), for example in conjunction with solar thermal collectors, 2-Sol (solar-thermally regenerated geothermal probes) or ice storage systems. For single-family homes, however, these heat pump sources or seasonal storage systems often lead to high investment costs and are not economically convincing. For this reason, an air-to-water heat pump is often installed in detached houses. However, the efficiency of a heating system with an air-to-water heat pump is not very good (annual coefficient of performance of 2.5 - 3) and the noise emissions also make air-to-water heat pumps unpopular in some cases.
In the L-Sol system, a “cold storage tank” is used on the source side of the heat pump. The heat peaks from the PVT collectors can be stored in this. This means that the heat pump can be operated with higher flow temperatures than if the heat is obtained exclusively from the outside air, as is the case with the air-to-water heat pump system. Compared to systems with geothermal probes or ice storage, the advantages of L-Sol are expected to be more on the economic side, and compared to the air-to-water heat pump more on the ecological side.
Potential
The system is considered for different building standards (new Minergie buildings and renovated old buildings) and costs and benefits are analyzed. The influence of different storage sizes on the primary and secondary side of the heat pump is also examined and the potential for optimization is explored.
Related Projects
Investigation of a heating and cooling concept for residential buildings and quarters of different sizes, which uses hybrid collectors (PVT collectors) and an insulated, open-bottomed underground storage tank as buffer and long-term storage. ExSolStore
Investigation of possibilities for the regeneration of geothermal probes with solar thermal energy in residential districts using simulations. SolSeasStore
A federal demonstration plant with approx. 180 PVT modules is operated on the roof of the lintharena sgu. PVT solar power plant linth-arena sgu
At the ZHAW in Wädenswil, the suitability of hybrid modules for various applications is being investigated using a PVT test plant. PVT test plant
Project Financing and Thanks
With this project, we are participating in the IEA Task 60 PVT systems. The project is funded by the Swiss Federal Office of Energy, SFOE.
