Energy-saving microgrid system for underground in-situ heating of oil shale integrating renewable energy source: An analysis focusing on net present value

• Published in: Journal of the Taiwan Institute of Chemical Engineers 2023-07, Vol.148, p.104717, Article 104717
• Main Authors: Zheng, Shuangjin, Fu, Shaojie, Pu, Yu, Li, Dong, Arıcı, Müslüm, Wang, Di, Yıldız, Çağatay
• Format: Article
• Language: English
• Subjects: Annual net present cost; Microgrid system; Oil shale; Renewable energy system; Underground in-situ electric heating; Well spacing
• ISSN: 1876-1070; 1876-1089
• DOI: 10.1016/j.jtice.2023.104717

•A microgrid system considering renewable energy and diesel power generation.•Effect of electric heating well spacing, oil shale extraction area, and diesel price.•Total annual net present cost is used as an evaluation metric.•Annual wasted electricity ratio increases by 2.96-fold with rising diesel price.•Well spacing of 10 m is the most energy-efficient one. The technology of underground in-situ electric heating for oil shale extraction requires a large amount of electrical energy, which is one of the important factors restricting its further development. In this paper, a microgrid system is proposed, which combines renewable energy sources with conventional ones, to supply electricity for the underground in-situ electric heating installations of oil shale. The system takes the annual net present value as the evaluation index to determine the optimal solution considering the effects of oil shale electric heating well spacing, oil shale extraction area, and diesel price. The results showed that the spacing of electric heating wells plays a significant role in energy requirement, an increment of 271,195.00$ in the average annual costs is noted when 12 m of the spacing is considered instead of 10 m. Moreover, diesel fuel prices remarkably affect the annual costs, and increasing diesel price from 0.4 to 0.8 $ per liter causes an increase of 58.5% in the average annual costs. Furthermore, this situation increases the annual wasted electricity ratio by 2.96-folds. This study provides a useful reference for decision-makers to design the power supply scheme for underground in-situ electric heating of oil shale.