Techno-economic assessment and optimization of a hybrid renewable earth - air heat exchanger coupled with electric boiler, hydrogen, wind and PV configurations

Energy sectors are responsible for most of greenhouse gas emission in the world. Significant amount of energy is consumed by the residential sector, highlighting the importance of developing sustainable energy technologies for this sector. In the current study, the behavior of an earth - air heat exchanger is simulated numerically, and the results are validated against the existing experimental data. To improve reliability and sustainability, the heat exchanger is coupled with a hybrid renewable energy system, including wind, solar and hydrogen. The performance of this system is explored in continuous and intermittent modes over a period of one month. The results show that nearly half of the drop in total performance of the system occurs during the first working day. Further, running the system intermittently result in an 8% rise in the effectiveness and around 31.55 MJ energy delivery over the period of a month. This implies that the long-term behavior of the system can be determined by monitoring its behavior on the first day of operation. It is also demonstrated that adding geothermal energy to hybrid renewable energy system can lead to an improvement of about 5.5% of the renewable fraction, decrease emissions and diesel consumption by almost 48%. (C) 2019 Elsevier Ltd. All rights reserved.