| Keywords |
Solar water heater ; Effective solar radiation ; Water supply temperature ; Applicability estimation |
| Abstract |
The objective of this work is to evaluate the applicability of small-scale residential solar water heater (SWH) according to solar radiation and water supply temperature in Korea from energy, environmental and economic perspectives. In this study, it was assumed that SWH consists of storage tank of 300 L and solar collectors of 6 m2 with an azimuth angle of 0° and a tilt angle of 35°. The results show that the solar radiation incident on the collector and the effective solar radiation actually used in the hot water supply are not in a proportional relationship, thus it is necessary to estimate the energy performance of the SWH based on an effective solar radiation rather than a solar radiation of the meteorological data. It is also observed that greenhouse gases emission reduction of SWH vary by region, up to 14% and it is about 120% better to replace electric boilers than gas boilers through the application of SWH. The economic evaluation results show that if the SWH replaces the gas boiler without receiving the subsidy, the investment cost is not recovered within analysis period of 20 years, whereas if the SWH replaces the electric boiler, the cost is recovered in 12~13 years. This is because electricity saving cost is about 108~132% larger than gas saving cost. Therefore, it is expected that the SWH will provide better economic effect when replacing electric boiler. |