Journal of the Korean Solar Energy Society ISSN:1598-6411(Print) 2508-3562(Online) 한국태양에너지학회 논문집

As regulations on renewable energy are strengthened and zero-energy buildings are becoming mandatory, research on the commercialization of renewable energy for heating and cooling buildings is accelerating. However, geothermal, photovoltaic, and solar heat are mostly applied as single systems, and there are few cases in which the disadvantages of individual systems are overcome or where the advantages are maximized. The purpose of this study is to develop an analysis model that can respond stably to heating and cooling loads in buildings and to analyze system performance. To stabilize the control of cooling, heating, and hot water supply, the operation method is divided into four cycles. In seasons when cooling and heating loads are significantly decreased, heating and cooling are performed directly by the heat pump without using storage tanks. In addition, a case study using late-night power was conducted to investigate efficient electricity use. Without late-night power, the heat pump coefficient of performance (COP) during the heating period was 2.5 and the monthly average heat exchange rate (HER) was 240 kWh; meanwhile, the COP during the cooling period was 3.99 and the HER was 880 kWh. The energy self-sufficiency rate during the heating period was 2.02 times higher than the cooling period. However, as a result of using late-night power, the electricity rate and COP during heating decreased by 2.5% and 2.04%, respectively, and the COP during cooling increased by 0.1%. This study presents basic data for the implementation of renewable energy systems and the design of predictive models.