TECHNO-ECONOMIC FEASIBILITY OF SOLAR ASSISTED HEAT PUMP (SAHP) SYSTEMS FOR EUROPEAN SINGLE-FAMILY HOUSES

Buildings account for about one-third of the global energy consumption and one-quarter of the total greenhouse gas emissions that cause global warming. These percentages are even higher in the single-family residential houses of the developed regions, such as Europe, due to the high living standards. As a solution, the building structures need to be more energy efficient in terms of construction and sustainable in terms of the energy supply side. However, research has shown that there are yet no building construction guidelines in around 110 countries worldwide. In addition, solar-assisted heat pump (SAHP) technology is one of the most promising solutions that can be applied to the single-family houses to reduce energy consumption, to electrify & meet all energy demands, and to increase the renewable energy share of the building sector. Despite the advantages, however, there is still a significant lack of awareness and a limited number of applications for the SAHP system in the building sector today. This thesis therefore investigates the techno-economic feasibility of different SAHP systems in residential single-family houses in order to unlock the full potential of the technology while ensuring that the energy demand side management is in line with the regional building standards. In order to actualize these objectives, a model-based formalised methodology has been implemented to design, validate, and analyse a representative typical single-family house and two different SAHP systems by employing the commercial software packages of TRNSYS and EES.
The results on the house model have demonstrated that the largest energy demand vector of a single-family residential house in European region is usually the space heating & cooling (SH & SC), followed by electrical energy (EE) for the household equipment, and domestic hot water (DHW). Moreover, it has been shown that the dynamic behaviour on the demand side is crucially important as it permits a better assessment of the performance of the energy delivery systems in real conditions. Regarding the technology implementation, the first proposed SAHP system is designed for a case study under the climatic boundary conditions of an EU candidate country. The results of this system showed that a basic SAHP configuration (PV+ air-HP) can satisfy the energy demand of 10077 kWh, which is the sum of all energy demand vectors of the representative house, with 20.15 m2 PV installation when HP is connected and 38.3 m2 PV installation when HP is disconnected. Moreover, the economic indicators have revealed that the system’s payback time is 6.8 years and the LCOE is 0.121 €/kWh, proving that the system has already reached the grid-parity in the location of interest (compared to the grid energy price, 0.130 €/kWh). The second proposed SAHP system is designed under the climatic boundary conditions of three different European countries, representing cold, moderate, and hot climates. The results of this system have shown that an innovative configuration (PV/T+ water-HP) can perform better and substantially reduce the SH and DHW needs of the representative house in all climates. However, the techno-economic analyses have revealed that such systems may not be feasible for cold climates, while excellent results have been obtained for moderate and hot climates. In these locations, the proposed system can cover 9843.6 kWh and 7365.6 kWh of energies (which are the sum of SH, DHW, and EE demand vectors of the representative house) with 14.7 m2 and 10.8 m2 of PV/T installations, respectively. Also, the payback time and LCOE of the system are calculated as 7.4 years-0.122 €/kWh for the moderate climate (compared to the grid price of 0.123 €/kWh) and 7.5 years-0.177 €/kWh for the hot climate (compared to the grid price of 0.241 €/kWh), respectively. Furthermore, the implications of all results are critically discussed.