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Shale gas, due to its clean-burning and efficient nature, is becoming an increasingly promising alternative energy resource. It is commonly held that promoting shale gas development will gradually play a significant role in meeting the energy needs of economic and social development as well as reducing harm to the environment. Given the significant implications, many countries are pursuing shale gas opportunities. However, numerous concerns have been raised about the economics of shale gas development, as it is difficult to evaluate. Accurately evaluating the economic viability of shale gas development to reduce investment risks and increase investment opportunity is the key issue that needs to be urgently addressed. This paper presents a systematic review and examination of the technical and economic evaluation techniques for the development of shale gas to provide an overview of their current status. Over time, some progress has been made in existing technical–economic evaluation techniques. It is worth noting that these techniques need to be further improved to more precisely assess the economic feasibility of developing shale gas for assisting investment decisions effectively. For this reason, various potentially useful ideas and approaches are presented to propose some potential improvement in evaluation techniques for shale gas development, which may materialize in possible future trends.

Abstract A variety of novel, recyclable and reusable, construction materials has already been studied within literature during the past years, aiming at improving the overall energy efficiency ranking of the building envelope. However, several studies show that a delicate control of indoor climating elements can lead to a significant performance improvement by exploiting the building’s savings potential via smart adaptive HVAC regulation to exogenous uncertain disturbances (e.g. weather, occupancy). Building Optimization and Control (BOC) systems can be categorized into two different groups: centralized (requiring high data transmission rates at a central node from every corner of the overall system) and decentralized 1 (assuming an intercommunication among neighboring constituent systems). Moreover, both approaches can be further divided into two subcategories, respectively: model-assisted (usually introducing modeling oversimplifications) and model-free (typically presenting poor stability and very slow convergence rates). This paper presents the application of a novel, decentralized, agent-based , model-free BOC methodology (abbreviated as L4GPCAO) to a modern non-residential building (E.ON. Energy Research Center’s main building), equipped with controllable HVAC systems and renewable energy sources by utilizing the existing Building Management System (BES). The building testbed is located inside the RWTH Aachen University campus in Aachen, Germany. A combined rule criterion composed of the non-renewable energy consumption (NREC) and the thermal comfort index – aligned to international comfort standards – was adopted in all cases presented herein. Besides the limited availability of the specified building testbed, real-life experiments demonstrated operational effectiveness of the proposed approach in BOC applications with complex, emerging dynamics arising from the building’s occupancy and thermal characteristics. L4GPCAO outperformed the control strategy that was designed by the planers and system provider, in a conventional manner, requiring no more than five test days.

Abstract In the past, most studies considered solar as a drawback to road pavement, especially the asphalt pavement. Not only its radiation causes the asphalt aging, simultaneously with high temperature, asphalt pavement contributes to the urban heat island (UHI) effect. In recent, as the world becomes more supportive towards implementing sustainable energy as the alternatives to the scarcity of non-renewable resources, utilizing the abundant solar radiation as the main source of energy has gradually attracted attention from both industries and academia with its potentials, including solar application on roads. Nevertheless, more researches have focused on the potential energy collection with less consideration to simultaneously overcome the side effects of abundant solar radiation on its lifecycle. This study found the necessity to review a comprehensive correlation between solar radiation and asphalt pavement from both positive and negative effects. The negative effects included asphalt aging and its effects on surroundings i.e. UHI effect. Meanwhile, the positive effects included exhaust purification and solar energy conversion into other forms of energy that can be used by humans using pavement solar heat collection for winter snowmelt, thermoelectric technology and photoelectric technology to convert solar energy into electrical energy. The cases in various application scenarios were analysed and summarized and the existing problems in the current research were proposed in this paper. Also, the reflection on the transformation of road design concept from “avoiding harm” to “seeking profit” was included. Finally, a new concept of “solar-road harmonious symbiosis” for future road application was proposed based on a comprehensive review of previous published works. It is also the new suggestion to scholars on the treatment of solar diseases on roads to prolong its symbiosis functions.

Abstract The automotive operating protocols is a comprehensive expression of a country or a region’s road, climatic environment and driving habits. It is the foundation of energy consumption, test method and limit method for automobile products. It has direct impact on R & D, production and government access management of enterprises. For fuel cells vehicles, the lifetime is one of the main factors restricting their commercialization. Furthermore, the lifetime evaluation methods and its standard specifications of vehicular proton exchange membrane fuel cell are the critical factors to its technological development, but there is no authoritative recognized life evaluation method and test protocols so far. A logical fuel cell durability test protocol is the fundamental for developing the fuel cell life evaluation methods. A review on the state-of-art in the world for fuel cell accelerated test protocols was given, the research circumstances of different universities and research institutions in China, America, the European Union, Japan and so on are analyzed and summarized in detail. Then the essential characteristics and applicable environments of a comprehensive and effective durability test protocol are summarized based on the analysis and demonstration of the existing durability test protocols in literature. The work in this paper focuses on the research of durability test protocols of the fuel cell stack for the first time. The final conclusion will provide theoretical basis for establishing fuel cell durability test specifications and proposing life evaluation methods, and make a contribution to the long life research of vehicular fuel cells.

As one of the three high-energy consumption sectors (industry, building, and transportation) in China, the transport sector faced a devastating resource and environment challenge. The transport sector was reportedly responsible for about 15.9% of the country’s total final energy consumption in 2008. This paper investigates the energy consumption and efficiency of China’s transport sector from 2003 to 2009. The transport energy data of 30 China administrative regions were divided into “three-belts” (Eastern, Western, and Central areas), and the corresponding turnovers were reported and analyzed using an index decomposition analysis (Logarithmic Mean Divisia Index). The energy data and turnover of the transport sector indicated that the high growth rate of turnover results is attributed to the high growth rate of diesel, assuming that diesel is the major fuel for freight transport. The growth of diesel is the main contributor to the overall growth of energy consumption. The growth rate of gasoline has become minimal since 2006. Since 2005, all three-belt areas, with regard to the effectiveness of energy conservation policies, have continuously improved their energy efficiencies based on the results of decomposition analysis. The energy intensity effect shows that the energy conservation and efficiency policies were more effective in the Central and Western areas than that in the Eastern area. On the other hand, the regional shift effect indicates that the policies favor to the Eastern area since only its regional shift effect contributes energy savings since 2008. The energy-mix effect is insignificant, which indicates that it is not necessary to conduct CO2 emission decomposition analysis due to the redundant observations. At last, the activity effect dominates the energy consumption increase (98.05% of the accumulated total energy increase) from 2003 to 2009, which is consistent with the rapid development of transportation in China. That is, the policies in the transport sector mainly focused on the economic development but the energy efficiencies in the study period.

Abstract Reducing a building’s energy consumption and providing better indoor environmental quality (IEQ) are the two major issues that building professionals are facing all over the world. It is not easy, however, to simultaneously address both issues. Therefore, this study aimed to establish the optimal occupant behavior that can simultaneously reduce total energy consumption and improve the IEQ, using an energy simulation and optimization tool. This study also developed an integrated IEQ score by combining three different IEQ indices (i.e., thermal comfort, indoor air quality (IAQ), and visual comfort) for building users to easily understand the IEQ condition. To analyze the effects of occupant behavior by region, the education facility was selected as the target facility, and five target regions were selected considering the Koppen climate classification system and the C40 Cities Climate Leadership Group. Finally, a total of 5 × 1.01 × 1022 occupant behavior combinations can be generated in the five target regions. As a result, among the four target variables (i.e., total energy consumption, thermal comfort, IAQ, and visual comfort), the total energy consumption of the optimal solution was found to have changed most dramatically compared to that of the basic condition in terms of percentage (94.7%), due to its strong correlation with the overall occupant behavior (the highest correlation coefficient: 0.879). Therefore, it is shown that occupant behavior has more influence on the total energy consumption than on the three IEQ indices. Among the three IEQ indices, the IAQ of the optimal solution decreased most significantly compared to that of the basic condition (the highest reduction ratio: 4.04% in Ulsan), which indicates that the IAQ has more influences on the integrated IEQ score than thermal and visual comfort. The facility manager and the building user can operate the building for reducing total energy consumption and improving the IEQ considering occupant behavior, which can be used as the building management guideline in various regions.

Abstract Cities are the major contributors to energy consumption and CO2 emissions, as well as being leading innovators and implementers of policy measures in climate change mitigation. Guangdong-Hong Kong-Macao Greater Bay Area (GBA) is an agglomeration of cities put forward by China to strengthen international cooperation among “Belt and Road” countries and promote low-carbon, inclusive, coordinated and sustainable development. Few studies have discussed the emission characteristics of GBA cities. This study, for the first time, compiles emission inventories of 11 GBA cities and their surroundings based on IPCC territorial emission accounting approach, which are consistent and comparable with the national and provincial inventories. Results show that (a) total emissions increased from 426 Mt in 2000 to 610 Mt in 2016, while emissions of GBA cities increased rapidly by 6.9% over 2000–2011 and peaked in 2014 (334 Mt); (b) raw coal and diesel oil are the top two emitters by energy type, while energy production sector and tertiary industry are the top two largest sectors; (c) GBA cities take the lead in low-carbon development, emitted 4% of total national emissions and contributed 13% of national GDP with less than a third of national emission intensities and less than three-quarters of national per capita emissions; (d) Macao, Shenzhen and Hong Kong have the top three lowest emission intensity in the country; (e) most of GBA cities are experiencing the shift from an industrial economy to a service economy, while Hong Kong, Shenzhen, Foshan and Huizhou reached their peak emissions and Guangzhou, Dongguan and Jiangmen remained decreasing emission tendencies; (g) for those coal-dominate or energy-production cities (i.e. Zhuhai, Zhongshan, Zhaoqing, Maoming, Yangjiang, Shanwei, Shaoguan and Zhanjiang) in mid-term industrialization, total emissions experienced soaring increases. The emission inventories provide robust, self-consistent, transparent and comparable data support for identifying spatial–temporal emission characteristics, developing low-carbon policies, monitoring mitigation progress in GBA cities as well as further emissions-related studies at a city-level. The low-carbon roadmaps designed for GBA cities and their surroundings also provide a benchmark for other developing countries/cities to adapting changing climate and achieve sustainable development.

Coal-based power generation accounts for over two fifths of global electricity supply and is supposed to be continuing its leading role in the coming decades. However, an integrated embodied energy accounting for typical coal-fired power system seems to be in its vacancy. To help erect a benchmark for energy analysis of electricity production, this study has for the first time established a complete inventory of energy inputs in the life cycle of a typical coal-fired power plant. Distinguished from previous works, with the support of ecological input–output database, this paper gives full consideration to the energy embodied in materials, equipment and services that have been traditionally neglected. The indirect energy cost is illustrated to be a non-negligible component, sharing around one-tenth of the total. This work could be a reference example for holistic energy evaluation of power generation systems worldwide. In current context of energy conservation and emissions abatement, it is of significant importance as the retrofitting of power generation systems may initiate large amounts of indirect energy cost. Besides, by calculating the nonrenewability indicator for the typical coal-fired power system, the energy saving potentials of several renewable alternatives are enunciated in this work. It may provide essential implications for policy makers in renewable deployment.

Abstract Considering the regular characteristics of city bus routines, dynamic programming (DP) is much better than rule-based strategy in developing the global optimal control strategy for a dual-motor coaxial coupling propulsion electric bus (DMCEB). However, its complexity and computational burden hinder the implementation capability. To solve the trade-off problem between optimum and practicability, a novel systematic extraction method of energy management strategy is proposed in this paper. Globally, DP is applied offline to find optimal operating points of propulsion components. Explicit shift schedule lines are designed by utilizing nonlinear support vector machine (SVM) with a new efficient factor tuning method. Torque split ratio (TSR) is extracted statistically in quadratic functions by using recursive k-means clustering and piecewise polynomial fitting methods. Then integrated rule-based strategy can be developed systematically and implemented online with proper operating range and limits. Eventually, hardware-in-the-loop (HIL) experiment results demonstrate that the proposed method can be executed through a 16-bit onboard processor in real-time. The online performance of the improved strategy is highly consistent with simulation results, which can reduce energy consumption by 21.06% compared to the preliminary heuristic strategy. Moreover, the applicability of the proposed methodology is further verified over different typical driving cycles.