ST-16-C059 -- Solar Hybrid and Geothermal Combined: New System Solution

This paper presents the energy efficiency, cost effectiveness and development potential of a new energy supply concept. The concept is based on solar hybrid, connected to three ground source heat pumps. A solar hybrid is a photovoltaic cell combined with a solar collector, the hybrid thus produces both heat and electricity. The hybrid is constructed so that the back of the photovoltaic is cooled with a closed water circuit. 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 330 m²(3552 ft²) solar hybrid panels and three ground-source heat pumps with eleven bore holes. Detailed monitoring of this full scaled system was performed during 2015. The analysis of the measurements aimed at quantifying 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 to optimize the system solution. Adjustments advices for improvements of the regulation strategies were suggested and implemented after only a few months of monitoring. The experiences from the housing association have been investigated through interviews and enquiries in parallel to the monitoring. The habitants in the association are in general satisfied with their new heating system.