Bing Wang^1,2, Kailei Deng¹, Liting He¹, Zhenming Sun^1,*

Energy Engineering, Vol.118, No.5, pp. 1333-1351, 2021, DOI:10.32604/EE.2021.014258

Abstract China has implemented both quantitative and policy incentives for renewable energy development since 2019 and is currently in the policy transition stage. The implementation of renewable portfolio standards (RPSs) is difficult due to the interests of multiple stakeholders, including power generation enterprises, power grid companies, power users, local governments, and the central government. Based on China’s RPS policy and power system reform documents, this research sorted out the core game decision problems of China’s renewable energy industry and established a conceptual game decision model of the renewable energy industry from the perspective of local governments, power generation enterprises and power… More >

Wei Zhang^1,2, Qihui Ling^1,2,*, Qiancheng Zhao^1,2, Hushu Wu³

Energy Engineering, Vol.118, No.5, pp. 1515-1535, 2021, DOI:10.32604/EE.2021.014162

Abstract The condition monitoring and fault diagnosis have been identified as the key to achieving higher availabilities of wind turbines. Numerous studies show that the open-circuit fault is a significant contributor to the failures of wind turbine converter. However, the multiple faults combinations and the influence of wind speed changes abruptly, grid voltage sags and noise interference have brought great challenges to fault diagnosis. Accordingly, concerning the open-circuit fault of converters in direct-driven PMSG wind turbine, a diagnostic method for multiple open-circuit faults is proposed in this paper, which is divided into two tasks: The first one is the fault detection… More >

Dan Wu¹, Yanbo Che¹, Wei Li^2,*, Wei He³, Dongyi Li⁴

Energy Engineering, Vol.118, No.5, pp. 1549-1564, 2021, DOI:10.32604/EE.2021.014818

Abstract With the significant progress of the “coal to electricity” project, the electric kiln equipment began to be connected to the distribution network on a large scale, which caused power quality problems such as low voltage, high harmonic distortion rate, and high reactive power loss. This paper proposes a two-stage power grid comprehensive resource optimization configuration model. A multi-objective optimization solution based on the joint simulation platform of Matlab and OpenDSS is developed. The solution aims to control harmonics and optimize reactive power. In the first stage, a multi-objective optimization model is established to minimize the active network loss, voltage deviation,… More >

Yinhe Bu¹, Xingping Zhang^1,2,3,*

Energy Engineering, Vol.118, No.4, pp. 1095-1109, 2021, DOI:10.32604/EE.2021.015893

Abstract With the explosive growth of variable renewable energy, the balance between the supply and demand of the power grid is faced with new challenges. Based on the development experience from typical countries and the state quo in China, this paper further analyzes the system architecture and development trend of demand response under the background of Energy Internet. Five dimensions are considered: Energy Internet platform, demand response application scenarios, system architecture, information technology system construction, and demand response development trend. The results show that the application of the Energy Internet platform can effectively solve the problems of data acquisition and processing,… More >

Nan Li¹, Ruiyang Xu¹, Caihong Zhang^1,*, Guoping Wu²

Energy Engineering, Vol.118, No.4, pp. 1185-1195, 2021, DOI:10.32604/EE.2021.014741

Abstract An improved radiation transmission and thermal efficiency model for solar ponds has been proposed based on both the Hull Model and Wang/Seyed-Yagoobi Model in this paper. The new model is more accurate to actual measured conditions because multiple reflections and turbidity effects are included. Absorption penetration, thermal conductivity loss and thermal efficiency under different Non-Convective Zone thicknesses are numerically analyzed and thoroughly discussed. The results show that ΔT/I0 plays a critical role for the thermal efficiency of solar pond. Furthermore, it is found through calculation that there is an optimum thickness of the Non-Convective Zone. When the Non-Convective Zone thickness… More >

Huiwen Xu^*, Zhen Wang

Energy Engineering, Vol.118, No.4, pp. 1027-1043, 2021, DOI:10.32604/EE.2021.015028

Abstract In recent years, China has developed rapidly in terms of natural gas. Driven by regional economic integration, a regional natural gas market composed of neighboring provinces and cities has taken shape gradually, and it tends to grow toward the same direction in policy formulation, resource coordination, facility construction and market expansion. Based on the factors such as geographical location, economic conditions and natural gas consumption, this thesis tends to conduct a horizontal comparative analysis on the economic development conditions, natural gas consumption characteristics and natural gas pipeline network density of the three regions with obvious regional integration feature in China.… More >

M. N. Tarhuni^*, W. R. Sulaiman, M. Z. Jaafar, M. Milad, A. M. Alghol

Energy Engineering, Vol.118, No.4, pp. 761-795, 2021, DOI:10.32604/EE.2021.016645

Abstract Fluid flow in fractured media has been studied for decades and received considerable attention in the oil and gas industry because of the high productivity of naturally fractured reservoirs. Due to formation complexity and reservoir heterogeneity, characterizing fluid flow with an appropriate reservoir model presents a challenging task that differs relatively from homogeneous conventional reservoirs in many aspects of view, including geological, petrophysical, production, and economics. In most fractured reservoirs, fracture networks create complex pathways that affect hydrocarbon flow, well performance, hence reservoir characterization. A better and comprehensive understanding of the available reservoir modeling approaches is much needed to accurately… More >

Sandhia Bai¹, A. K. Amirruddin¹, A. K. Pandey^2,*, M. Samykano^1,*, Muhammad Shakeel Ahmad³, Kamal Sharma⁴, V. V. Tyagi⁵

Energy Engineering, Vol.118, No.4, pp. 737-759, 2021, DOI:10.32604/EE.2021.016157

Abstract The global increase in energy demand has resulted in the depletion of non-renewable resources and caused environmental degradation. Consequently, emerging renewable technologies are a potential solution to fulfil energy demand and mitigate the effect of global warming. Low-cost solar energy harvesting technologies are most feasible technologies. Various solar cells technologies have been developed with improved overall performance and conversion efficiency. However, due to low cost and a wide range of applications, dye-sensitized solar cells (DSSCs) have been immensely focused on one of the most promising third-generation solar cells. The highest conversion efficiency of DSSC achieved after three decades of research… More >

Ruma Arora Soni^1,*, K. Sudhakar^1,3,4,*, R. S. Rana²

Energy Engineering, Vol.118, No.4, pp. 1045-1056, 2021, DOI:10.32604/EE.2021.016082

Abstract Spirulina is a sort of algae that grows in both fresh and seawater. It is considered the Earth’s most nutritionally dense food. Certain claims about Spirulina’s beneficial health properties are attributed to the relatively high protein content of the cells. Spirulina’s lipid, fatty acid profile, and biochemical composition have received little attention. The purpose of this study is to investigate the nature and decomposition of spirulina biomass at various temperatures. In the present investigation, Fourier transforms infrared spectroscopy, thermogravimetric analysis, and elemental analysis were used to study spirulina biomass biochemical characteristics. The optimal content of spirulina protein, lipid, and the… More >

Maatouk Khoukhi^*, Omar Al Khatib

Energy Engineering, Vol.118, No.4, pp. 875-909, 2021, DOI:10.32604/EE.2021.015835

Abstract This paper reviews the principle and application of the thermally activated desiccant cooling systems with their capability to perform efficiently in hot-humid climates. The paper first introduces the continuous increase of thermal comfort required in building and their relation with the consumption of conventional energy sources. The importance of desiccant cooling technology and its applications has been introduced as well. The energy and environmental issues with the conventional energy supply and the demand with the environmental problems and conditions mainly related to indoor air quality have been also discussed in the second chapter of this paper. The third part of… More >