Solar Hybrid and Geothermal Combined: New System Solution for Renewables (ST-16-C059)

This paper presents the energy efficiency, cost effectiveness and development potential of a new energy supply concept. The concept is based on solar hybrid, bore hole heat storage and a ground source heat pump. The back of the photovoltaic cells is cooled with cold water to increase the efficiency. The heated water is then connected to the cold side of a ground-source heat pump (GSHP) and to bore holes. The heat from the solar hybrid can be used in several ways to increase the efficiency of the heat pump, e.g. as the direct source of heat or to recharge the bore holes. A housing association consistent of 70 terraced houses on the west coast of Sweden has installed this new system solution. The system consists of 337 m²solar hybrid panels mounted on the roof of the terraced houses, and GSHP with seven bore holes. During the year of 2015 detailed measurements on this full scaled system is performed. In this paper presents the results from these measurements, as well as analysis of the data. The analysis aims to quantify the energy efficiency of the system. The first results show that the system has a good efficiency and that the energy demand has decreased significantly. The monitoring has also been used as a tool to adjust the system and optimize the system solution. After only a few months of monitoring adjustments advices for improvements of the regulation strategies were suggested and implemented. These changes have led to a system that is now even more efficient than at the initial installation. In parallel to the monitoring the experiences from the housing association is investigated through interviews and enquiries. In the paper their perception of common ownership, obstacles in the implementation and advices on procurement will be presented. The paper aims to increase the knowledge about this system solution with solar hybrid and geothermal combined. The increased knowledge will eventually lead to a broader implementation of this system solution with 100 % renewables.