________________________________ * Author', e-mail: scoskun1968@gmail.com PERFORMANCE ANALYSIS OF A SOLAR-ASSISTED GROUND SOURCE HEAT PUMP SYSTEM IN CLIMATIC CONDITIONS OF TURKEY Salih COŞKUN * Air Conditioning and Refrigeration Technology Program, Electrical and Energy Department, Vocational School of Technical Sciences, Uludag University, 16059 Görükle Bursa, Turkey In order to contribute to widespread use of renewable energy sources in Turkey, a solar-assisted ground source heat pump (SAGSHP) system was modeled using TRNSYS software and simulated for heating and supplying daily hot water to meet the needs of a restaurant in five sample provinces having different climatic conditions. During the simulation, the dining room temperature of the restaurant was kept constant at 22 °C during the winter season and a total of 300 L/h of water (55 °C) was used for 15 min four times a day. According to the simulation results, power consumption rates in the SAGSHP system were determined as about 60% for the heat pump, 16% for heaters, 14% for the ground pump and 8% for fans and other pumps. The highest power consumption, as expected, was obtained for Hakkari Province (6723 kW) in the Eastern Anatolia region, which has a cold climate, while the lowest power consumption was obtained for İzmir Province (2822 kW) in the Aegean region, which has mild climatic conditions. The lowest seasonal performance factor (SPF) and solar factor (SF) values were calculated as 2.27 and 32% for Hakkari and the highest as 2.71 and 56% for İzmir , respectively. Key words: SAGSHP, heating, hot water, simulation, TRNSYS 1. Introduction Primary energy sources in Turkey consist of 28% natural gas, 28% coal, 31% petroleum and 5% hydraulic energy and other renewable energy sources. Of these, 24% are used in the housing and service sectors [1]. While imported natural gas is used at the ratio of 38.3% in the residential sector, the use of renewable energy sources is limited. In the hot and humid climatic regions where natural gas is not available, split air conditioning units are used for cooling purposes in summer in addition to their use for heating purposes in winter. Moreover, hot water needs in these regions are supplied by using solar energy or electrical heaters. In the cold regions, the houses are heated by fossil fuel boilers, stoves or electrical heaters, while hot water needs are met by using electrical water heaters and fossil fuel stoves. In recent years, land-, lake- and well-sourced heat pumps have been used in places such as hotels and shopping centers in order to meet hot water demands other than for heating and cooling [2]. The split air conditioners used in particular for heating in warm climatic conditions are not suitable for cold climatic conditions because of decreased performance. Therefore, ground source heat pumps are