• Energy Research
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The power system ranks the first among the greatest engineering achievements in the 20th century. With “strong electric power” as the carrier, the power system constitutes the great aorta of modern society for energy transmission; while with “weak electric power” as the carrier, the information network constitutes the nervous system of modern society. Both of them penetrate into all aspects of human society (e.g., science, production, life, international relations), and then promote the modern civilization to achieve rapid development. In terms of science, the power system has promoted the developments of materials, physics, chemistry, automation, information, medicine, and so on. This way, the system of modern science and technology is constituted. In terms of production, the second industrial revolution marked by the wide application of “strong electric power” is also called the electric power technology revolution. It has promoted another major leap in the productivity of human society after the steam revolution. The third industrial revolution marked by the widespread application of “weak electricity” is also known as the information technology revolution, which promotes the continuous evolution of industrial civilization to a much higher level. And the fourth industrial revolution, which is centered on the energy revolution, will meet the needs of human beings at a higher level and get rid of the constraints of the environment on human activities. In terms of life, electric power has become the most indispensable part of human life, ranging from material life to spiritual life, from behavioral habits to thinking ways, and from personal life to social life. In terms of international relations, the development of the power system is conducive to the fundamental solution of energy and environmental problems, thus the international political and economic competition around energy and environment has turned to the competition centered on clean power systems to some extent. As the basic platform for energy production and supply, the development of the future power system must follow the general orientation of the energy revolution. The basic form, management mechanism and technical characteristics of the power system will also undergo tremendous changes as follows: (1) The proportion of renewable energy in the power system will be increased continuously, and the power system will be tightly coupled with gas system and thermal system to form an electricity-centric energy internet. (2) The development mode of building “higher, farther and larger” power grid will turn to the co-development mode of large power grid and small power grid, and the trend of power electronation of power system will be strengthened gradually. (3) Market competition will penetrate into the weak monopolies of the power system. Each subject can play a full game in each link, so as to obtain the optimal allocation of funds, technology and human resources. (4) Digitalization and intellectualization will be the most important technical characteristics of the future power system, which will achieve leapfrog development in observability, controllability and intellectualization.

In China, the power sector is currently the largest carbon emitter and the transportation sector is the fastest-growing carbon emitter. This paper proposes a model of solar-powered charging stations for electric vehicles to mitigate problems encountered in China’s renewable energy utilization processes and to cope with the increasing power demand by electric vehicles for the near future. This study applies the proposed model to Shenzhen City to verify its technical and economic feasibility. Modeling results showed that the total net present value of a photovoltaic power charging station that meets the daily electricity demand of 4500 kWh is $3,579,236 and that the cost of energy of the combined energy system is $0.098/kWh. In addition, the photovoltaic powered electric vehicle model has pollutant reduction potentials of 99.8%, 99.7% and 100% for carbon dioxide, sulfur dioxide, and nitrogen oxides, respectively, compared with a traditional gasoline-fueled car. Sensitivity analysis results indicated that interest rate has a relatively strong influence on COE (Cost of Energy). An increase in the interest rate from 0% to 6% increases COE from $0.027/kWh to $0.097/kWh. This analysis also suggests that carbon pricing promotes renewable energy only when the price of carbon is above $20/t.

This paper analyses the impact of postponing global mitigation action on abatement costs and energy systems changes in China and India. It compares energy-system changes and mitigation costs from a global and two national energy-system models under two global emission pathways with medium likelihood of meeting the 2 °C target: a least-cost pathway and a pathway that postpones ambitious mitigation action, starting from the Copenhagen Accord pledges. Both pathways have similar 2010–2050 cumulative greenhouse gas emissions. The analysis shows that postponing mitigation action increases the lock-in in less energy efficient technologies and results in much higher cumulative mitigation costs. The models agree that carbon capture and storage (CCS) and nuclear energy are important mitigation technologies, while the shares of biofuels and other renewables vary largely over the models. Differences between India and China with respect to the timing of emission reductions and the choice of mitigation measures relate to differences in projections of rapid economic change, capital stock turnover and technological development. Furthermore, depending on the way it is implemented, climate policy could increase indoor air pollution, but it is likely to provide synergies for energy security. These relations should be taken into account when designing national climate policies.

Abstract The industrial exhaust flue gas contains tremendous waste heat that cannot be efficiently recovered by conventional condensing heat exchanger. This paper proposes a novel full-open absorption heat pump for the total heat recovery of flue gas. The recovered heat is used for district heating. By applying direct-contact heat and mass transfer without solid transfer interfaces, the novel system can save considerable metallic tube or plate materials and therefore the initial investment can be reduced substantially. A prototype full-open absorption heat pump is developed and tested, achieving the COP (coefficient of performance) of 1.621 and the exit flue gas dew point of 36.2 °C at most. A detailed theoretical model in Eulerian–Lagrangian formulation is established, involving in conjugate heat and mass transfer and particle dynamics. The numerical simulation agrees well with the experiment results. On the basis of the validated model, three critical parameters, including excess air coefficient of the burner, moisture content of the objective flue gas and return water temperature of the district heating network, are selected to study their effects on system performances. As a controlled variable, especially, the excess air coefficient plays an important role by influencing the regeneration of the liquid absorbent in the generator. The full-open absorption heat pump outperforms the condensing heat exchanger by 19.7–178.1% in heat recovery capacity as the return water temperature increases from 40 to 55 °C.

China is confronted with an unprecedented water crisis regarding its quantity and quality. In this study, we quantified the dynamics of China?s embodied water use and chemical oxygen demand (COD) discharge from 2010 to 2015. The analysis was conducted with the latest available water use data across sectors in primary, secondary and tertiary industries and input?output models. The results showed that (1) China?s water crisis was alleviated under urbanisation. Urban consumption occupied the largest percentages (over 30%) of embodied water use and COD discharge, but embodied water intensities in urban consumption were far lower than those in rural consumption. (2) The ?new normal? phase witnessed the optimisation of China?s water use structures. Embodied water use in light-manufacturing and tertiary sectors increased while those in heavy-manufacturing sectors (except chemicals and transport equipment) dropped. (3) Transformation of China?s international market brought positive effects on its domestic water use. China?s water use (116?80 billion tonnes (Bts))(9) and COD discharge (3.95?2.22 million tonnes (Mts)) embodied in export tremendously decreased while its total export values (11?25 trillion CNY) soared. Furthermore, embodied water use and COD discharge in relatively low-end sectors, such as textile, started to transfer from international to domestic markets when a part of China?s production activities had been relocated to other developing countries.

The Chinese government has grown increasingly invested in ecology in recent years. This paper discusses eco-efficiency using data envelopment analysis on 48 cities in Bohai Rim with special focus on the role of industrial structure upgrades. Based on the values from a super undesirable slack-based model, this study investigates eco-efficiency from temporal and spatial perspectives to reveal gaps among Bohai cities but an overall improvement in regional eco-efficiency. Moreover, this study adopts the Global and Local Moran's I to identify positive spatial autocorrelations and shows that most cites in Bohai Rim have high-high, low-low aggregation characteristics. Plus, the economic effects of per capita GDP, industrial structure upgrades on eco-efficiency are determined according to a spatial Durbin model. There appear to be negative spillover effects of industrial structure upgrades on surrounding cities, which reflects an industry transfer phenomenon related to eco-efficiency.

Abstract How to increase clean energy utilization is a key issue in household energy consumption analysis aimed at alleviating air pollution and improving the health of residents. Clean energy substitution is a complex decision process between related stakeholders, and is affected by a combination of factors such as geographical location and household income. To evaluate the potential of clean energy promotion to contribute to better policy decisions and measures, an agent-based household energy consumption model is established to capture the group habits of different stakeholders and the impact mechanism of critical influential factors. Multi-layered structures including various types of households and energy consumption devices are modeled. The experimental results of several scenario analyses show that increased income, improved technology and subsidies from local governments can influence clean energy substitution in the household in various ways. These findings provide a better understanding of the energy cleaning process and decision-making support for governments.