Shaping China's energy security: The impact of domestic reforms

This paper is a subsequent study of China's energy security situation which concludes that China's energy security has not improved over 30 years of economic reform. The objective of the study is to explore qualitatively why the energy security situation has not improved. To answer the ‘why’ question, the study opens up a new perspective by analyzing the relationship between energy security and energy policies from the macroeconomic reform perspective. This study discusses major reforms that took place over 30 years. It is found that China's macroeconomic reform has restricted the formation of China's energy policies and determined its energy security situation. In essence, China's energy policies are only a reaction to the macroeconomic measures. In other words, China's energy policies are not originally intended to improve energy security, but passive reactions to China's macroeconomic reform. This explains why China did not improve its energy security situation despite 30 years of reform.     

Barriers' and policies' analysis of China's building energy efficiency

With the rapid economic growth and the improvement of people's living standards, China's building energy consumption has kept rising during the past 15 years. Under the effort of the Chinese government and the society, China's building energy efficiency has made certain achievements. However, the implementation of building energy efficiency in China is still far from its potential. Based on the analysis of the existing policies implemented in China, the article concluded that the most essential and the most effective ways to promote building energy efficiency is the government's involvement as well as economic and financial incentives. In addition, the main barriers in the process of promoting building energy efficiency in China are identified in six aspects. It has been found that the legal system and administrative issues constitute major barriers, and the lack of financial incentives and the mismatching of market mechanism also hamper the promotion of building energy efficiency. Finally, in view of the existing policies and barriers analysis, three corresponding policy proposals are presented.     

Principles, effects and problems of differential power pricing policy for energy intensive industries in China

The Chinese government canceled the preferential power pricing policies for energy intensive industries and imposed a reverse differential pricing policy in order to promote energy efficiency and the adjustment and upgrading of the industrial structure. This article analyzes the principles of China’s differential power pricing policy, the externalities of energy and the modified Ramsey pricing rule, and also points out the policy implications of China’s differential power pricing policy. In our samples, we investigate eight power intensive products in the Henan province with respect to their power consumption per unit (power intensity), electricity cost, total cost, the electricity tariff and profit, in order to test the effects of the differential power pricing policy. The results show that the primary effect of the differential power pricing policy is that enterprises decrease their total costs and improve their productive efficiencies in advance, in anticipating a higher electricity tariff.     

The status quo of China's nuclear power and the uranium gap solution

Mainland China has eleven nuclear power reactors in commercial operation; six are under construction, and several more are slated for development in the near future. Additional reactors are planned, including some of the world's most advanced, to give a fivefold increase in nuclear capacity up to 40 GWe by 2020, and then a further three to fourfold increase to 120–160 GWe by 2030. The natural uranium supply, however, does not correspond to the speed of nuclear power development because of low production and poor deposits. After examining the existing nuclear power status quo in China, this paper provides an experimental model and a calculation method for the natural uranium needed that is based on the nuclear capacity to be installed in 2014. The natural uranium gap is further discussed through an analysis of the uranium resource distribution, reserves, and production in China, together with approaches to fill the gap. To meet the imminent uranium peak that will be required for fuel demands, China should diversify natural uranium sources and develop advanced nuclear power systems to save fuel.     

China's experiment on the differential electricity pricing policy and the struggle for energy conservation

Differential electricity pricing was promulgated by China's central government to guide the development of high energy-consuming industries, which are significant for energy conservation. This paper examines the twists and turns of the policy implementation at the provincial level, and seeks to elucidate the difficulties in its implementation. Local governments, concerned that following the central directives would hurt local interests, have tried to deviate from the central orders while the central revises the policy from time to time to ensure local compliance. Three difficulties are analyzed: (1) the current relations between the central and local energy regulatory institutions make these local institutions difficult to perform their duties, and affect incentives for local governments to respond to central directives; (2) financial reform puts a great burden on local governments to raise revenues to cover expenditures, making local governments focus mainly on economic development rather than serving merely as political agents of the central government; (3) the aggressive attitude of local governments in pursuing GDP growth is not necessarily driven by the central government, but by pressure from competition among localities and the need to win local support. Solving these difficulties is important for making national energy conservation polices effective and efficient.     

China needing a cautious approach to nuclear power strategy

China is leading the recent revival of nuclear energy programs. The Chinese government plans to increase nuclear generating capacity to 40 GWe by 2020, while the installed capacity is 8.6 GWe in 2007. In view of the enthusiasm shown for nuclear electricity throughout the country, the actual scale of Chinese nuclear power development is expected to reach 70 GWe by 2020. However, the low cost proven uranium reverses (cost category to <130 US $/kg) in China only meet half demand of 40 GWe capacity in 2020. And overlying China's increased demand is continued political sensitivity about the uranium trade. Meanwhile, the capacity of China's spent fuel reprocessing cannot keep up with the increasing spent fuel. And the legal administrative system of radioactive waste and spent fuel management is outdated. Hence it is proposed in this paper that the accelerated development of nuclear power industry is not good, and the over-accelerated development may be harmful, without appropriately considering the uranium resources and spent fuel management.     

Hydropower in China at present and its further development

At present, China's economic development faces energy challenge, and the appropriate solution of energy bottleneck is the key to healthy, rapid and sustainable development. China's gross amount of hydraulic resource ranks first in the world; however, because of low level of development, hydraulic resource has a broad development prospect. Now, China's hydropower development is in its peak period. By the end of 2004, the gross installed hydropower capacity of China broke through 100 million kW. From there, it has remained in the top slot worldwide. The vigorous development of hydropower is necessary because of the energy shortage and environmental pollution in China in order to attain sustainable development of China's economy. Abundant hydraulic resource, huge market demands, the strategy of western development and the favorable environment of economic development provide hydropower construction with unprecedented advantages and opportunities. Chins hydropower development aims at an installed hydropower capacity of up to 194 million kW by 2010, accounting for 23.1% of the gross installed power capacity and 35% of hydropower resource. Finally, we present the general condition of Three Gorges project as well as the new mode of hydropower development of Three Gorges Project Corporation, i.e., cascade development.     

China's energy efficiency improvement on account of the development of wind and solar power: Applying a dynamic non-radial directional distance function

China is developing wind energy and solar power as the main channels to deal with climate warming and has put forward the goal of achieving peak carbon emissions by 2030 and carbon neutralization by 2060. Previous studies evaluating the nation energy efficiency rarely consider the impact of wind and solar power. Thus, different from past literature, this research introduces Carbon Emission Reduction Capacity (CERC) by wind and solar power as a new output variable and applies a dynamic non-radial directional distance function to evaluate China's energy efficiency from 2011 to 2019. The empirical results show that northwest provinces with their high proportion of wind and solar power present better energy performance, while some eastern and central provinces with high efficiency as seen in previous study have greater room for improvement of wind and solar power. It is suggested that the China government formulate more flexible policies to support the sustainable development of wind and solar power, so as to reduce the consumption of fossil energy and cope with climate warming.     

Estimates of the potential for energy conservation in the Chinese steel industry

The study evaluates the energy saving potential of the Chinese steel industry by studying its potential future energy efficiency gap. In order to predict the future energy efficiency gap, a multivariate regression model combined with risk analysis is developed to estimate future energy intensity of China's steel industry. It is found that R&D intensity, energy saving investment, labor productivity and industry concentration are all important variables that affect energy intensity. We assess the possible measures as to how China's steel industry can narrow the energy efficiency gap with Japan by means of scenario analysis. Using Japan's current energy efficiency level as baseline, the energy saving potential of China's steel industry is more than 200 million ton coal equivalent in 2008, and it would fall to zero in 2020. However, if greater efforts were made to conserve energy, it would be possible to narrow down the energy efficiency gap between China and Japan by around 2015. Finally, using the results of the scenario analysis, future policy priorities for energy conservation in China's steel industry are assessed in this paper.     

Assessment of China's climate commitment and non-fossil energy plan towards 2020 using hybrid AIM/CGE model

China made a commitment in Copenhagen to reduce its carbon dioxide emissions per unit of GDP from 40% to 45% compared with the 2005 level by 2020, and is determined to vigorously develop non-fossil fuels. This study analyzes the effects and impacts of policies that could help to achieve China's Copenhagen commitments with a hybrid static CGE model in which the electricity sector is disaggregated into 12 generation technologies. Four scenarios are developed, including the reference scenario A, the reference scenario B and two carbon constraint scenarios. The results show that carbon intensity in terms of GDP will fall by 30.97% between 2005 and 2020 in the reference scenario A, and will be reduced further by 7.97% if China's targeted non-fossil energy development plans can be achieved in the reference scenario B. However, the rest of the 40–45% target must be realized by other measures such as carbon constraint. It is also observed that due to carbon intensity constraints, GDP loss would be from 0.032% to 0.24% compared to the reference scenario B, and CO₂ emission reductions are due mainly to decreases in coal consumption in the electricity sector and manufacturing sector.     

Incorporating energy efficiency into electric power transmission planning: A western United States case study

Driven by system reliability goals and the need to integrate significantly increased renewable power generation, long-range, bulk-power transmission planning processes in the United States are undergoing major changes. At the same time, energy efficiency is an increasing share of the electricity resource mix in many regions, and has become a centerpiece of many utility resource plans and state policies as a means of meeting electricity demand, complementing supply-side sources, and reducing carbon dioxide emissions from the electric power system. The paper describes an innovative project in the western United States to explicitly incorporate end-use efficiency into load forecasts – projections of electricity consumption and demand – that are a critical input into transmission planning and transmission planning studies. Institutional and regulatory background and context are reviewed, along with a detailed discussion of data sources and analytical procedures used to integrate efficiency into load forecasts. The analysis is intended as a practical example to illustrate the kinds of technical and institutional issues that must be addressed in order to incorporate energy efficiency into regional transmission planning activities.     

Stored energy control for long-term continuous operation of an electric and hydrogen hybrid energy storage system for emergency power supply and solar power fluctuation compensation

In order to realize a large-capacity stand-alone emergency power supply that enables highly reliable and high-quality power supply at the time of a large-scale natural disaster and enables effective use of solar power generation, we proposed an electric and hydrogen hybrid energy storage system (HESS). It is composed of an electric double-layer capacitor bank, fuel cell, electrolyzer, and hydrogen storage (buffer gas tank and metal hydride). In an emergency, this HESS is expected to supply power for loads together with photovoltaics panels for a long time. In usual time, it should not only cooperate with external electricity grids to convert unstable photovoltaic output power into reliable power supply, but also maintain sufficient stored energy in case of emergency. To realize the continuous operation of the HESS in both emergency and usual time, we proposed an electric double-layer capacitor's state-of-charge feedback control method and a hydrogen energy feedback control method, coordinating an energy management method based on Kalman filter algorithm. An experiment and a simulation demonstrated the operations of a 10-kW scale model HESS in emergency and usual time mode, respectively. The demonstrations verified the correct performance of the proposed HESS with the proposed control methods and enabled the continuous operation of the HESS.     

Influence of the power supply on the energy efficiency of an alkaline water electrolyser

Electric energy consumption represents the greatest part of the cost of the hydrogen produced by water electrolysis. An effort is being carried out to reduce this electric consumption and improve the global efficiency of commercial electrolysers. Whereas relevant progresses are being achieved in cell stack configurations and electrodes performance, there are practically no studies on the effect of the electric power supply topology on the electrolyser energy efficiency. This paper presents an analysis on the energy consumption and efficiency of a 1 N m³ h⁻¹ commercial alkaline water electrolyser and their dependence on the power supply topology. The different topologies of power supplies are first summarised, analysed and classified into two groups: thyristor-based (ThPS) and transistor-based power supplies (TrPS). An Electrolyser Power Supply Emulator (EPSE) is then designed, developed and satisfactorily validated by means of simulation and experimental tests. With the EPSE, the electrolyser is characterised both obtaining its I–V curves for different temperatures and measuring the useful hydrogen production. The electrolyser is then supplied by means of two different emulated electric profiles that are characteristic of typical ThPS and TrPS. Results show that the cell stack energy consumption is up to 495 W h N m⁻³ lower when it is supplied by the TrPS, which means 10% greater in terms of efficiency.     

Continuous operation in an electric and hydrogen hybrid energy storage system for renewable power generation and autonomous emergency power supply

Under the background of extensive improvement of renewable resources and demand for reliable emergency power supply, we proposed a hybrid energy storage system including an electric double-layer capacitor bank and a hydrogen system which is composed of fuel cell, electrolyzer, gas tank and metal hydride tank. Through its integration with photovoltaic power sources in a local direct current grid, we expect to obtain both of stable energy source at ordinary times and long-time reliable autonomous emergency power supply when outages happen. A three-day demonstration of the proposed system was performed. The fluctuation compensation performance of the components and the long-time stable power supply obtained by the entire system were evaluated at first, hence the configuration and the management methods of the proposed system were verified in the autonomous emergency power supply application. Meanwhile, the performance of the hybrid use of the gas tank and the metal hydride tank in the system was preliminarily evaluated, for its effectiveness verification on reducing auxiliary power for temperature condition of the metal hydride tank. Moreover, we investigated the distribution characteristics of the power and energy loss in the electric double-layer capacitor, electrolyzer and fuel cell, and their correlation to the efficiency characteristics under different conditions during the operation. The investigation results showed that the continual low-load-ratio state of the electrolyzer and fuel cell led to the low efficiency, the rare high-power occurrence of the electrolyzer and fuel cell led their demanded excessive power capacity. Thus, we proposed a solution method of shifting the electrolyzer and fuel cell's load to the EDLC, when the electrolyzer and fuel cell are in low-load-ratio and excessive high-power state, in order for efficiency increase and facility capacity reduction.     

Stable power supply of an independent power source for a remote island using a Hybrid Energy Storage System composed of electric and hydrogen energy storage systems

We propose a self-sustaining power supply system consisting of a “Hybrid Energy Storage System (HESS)” and renewable energy sources to ensure a stable supply of high-quality power in remote islands. The configuration of the self-sustaining power supply system that can utilize renewable energy sources effectively on remote islands where the installation area is limited is investigated. It is found that it is important to select renewable energy sources whose output power curve is close to the load curve to improve the efficiency of the system. The operation methods that can increase the cost-effectiveness of the self-sustaining power supply system are also investigated. It is clarified that it is important for increasing the cost effectiveness of the self-sustaining power supply system to operate the HESS with a smaller capacity of its components by setting upper limits on the output power of the renewable energy sources and cutting the infrequent generated power.     

Vulnerability of the economy to the potential disturbances of energy supply: A logic-based model with application to the case of China

The disturbances of energy supply that may result from both external and domestic events create a significant threat for national economy due to potential impacts on the productivity, employment and overall economic growth. Building scenarios of the economy's vulnerability to these disturbances is delicate because of the significant number of interrelated factors that should be taken into consideration. In this paper, a logic-based model (LBM) is developed, which allows for defining, exploring and assessing the determinants and the indicators of the economy's vulnerability related to the energy supply disturbances within a coherent scenarios assessment framework. The proposed model is illustrated with the case of China. After developing the general framework, three particular scenarios are investigated. Based on the case study, the performance and limitations of the model are analyzed, and its ability to evaluate national energy policies is discussed. Finally, some recommendations for further improvements are made.     

A review of enhancing micro combustion to improve energy conversion performance in micro power system

With the development of microfabrication technology and micro devices, the demand for Power Micro Electro Mechanical System (Power MEMS) is ever-increasing. However, traditional chemical batteries are not suitable for Power MEMS due to their low energy density. The combustion of hydrogen and hydrocarbon fuels offers a more promising alternative to conventional batteries. However, micro combustion faces the problems of flame instability and low combustion efficiency. Therefore, improving flame stabilization and combustion efficiency in micro combustions is necessary. Studies have made considerable progress in these aspects over the last decade. This paper summarized these studies and classified the optimization schemes according to flame stabilization and combustion efficiency. Besides, research on the Field Synergy Principle was discussed. The synergy between the flow field and temperature gradient field in the micro-scale domain will become a key research area in the future. It is proposed to insert porous media in MTES and MTPVS and adopt catalytic combustion. Adding hydrogen to the mixed gas was recommended. The equivalence ratio of the mixed gas in the range of 0.9–1.1 would be best. The equivalence ratio is the ratio of the theoretical requirement of air with complete combustion to the actual supply of air.     

Use of hydrogen as a seasonal energy storage system to manage renewable power deployment in Spain by 2030

Spain has presented a plan (known as PNIEC) to reduce conventional energy sources (shutting down 16 GW) and to increase the use of renewable sources (incorporating 65 GW). This generation portfolio leads to a situation in which there will be a surplus of electrical energy in spring and summer, which will be lacking in autumn and winter. The plan sets a target on batteries, but insufficient to manage more than 10 TWh over 6 months. This paper proposes the deployment of electrolysers to produce hydrogen with the surplus energy, using the already existing Spanish natural gas network to store it. The resulting gas (up to 15% blend of hydrogen in natural gas) could be used subsequently in turbines to alleviate the energy deficit. With this strategy, up to 7.27 TWh of the surplus renewable energy could be reused, and 2.54 million tons of CO2 equivalent would be avoided yearly.     

Sizing methodology for hybrid systems based on multiple renewable power sources integrated to the energy management strategy

This work presents a design methodology for a hybrid energy system based on multiple renewable power sources and bioethanol. The new concept of generation consists on having multiple power sources such as a PEM fuel cell system fed by the hydrogen produced by a bioethanol reformer and wind-solar sources working all together supervised by the energy management system. The necessary heating for the bioethanol reforming reaction can be provided by the renewable sources to enhance the efficiency of the hydrogen production. It is worth noting that, from the power balance as well as backup point of views, the hybrid system is equipped with energy storage devices. An optimal sizing methodology integrated with the energy management strategy is proposed here for designing the overall hybrid system. The suggested approach is based on genetic algorithms, using historical climate data and load demands over a period of one year. Several simulation results are given to show the methodology performance in terms of loss of power supply probability (LPSP), costs and bioethanol consumption.     

A framework for siting and dispatch of emerging energy resources to realize environmental and health benefits: Case study on peaker power plant displacement

Emerging grid resources such as energy storage and demand response have the potential to provide numerous environmental and societal benefits, but are primarily sited and operated to provide grid-specific services without optimizing these co-benefits. We present a four-metric framework to identify priority regions to deploy and dispatch these technologies to displace marginal grid air emissions with high environmental and health impacts. To the standard metrics of total mass and rate of air pollutant emissions we add location and time, to prioritize emission displacement near densely populated areas with poor air quality, especially at times when air pollutant concentrations exceed regulatory standards. We illustrate our framework with a case study using storage, demand response, and other technologies to displace peaker power plants, the highest-rate marginal emitters on the California grid. We combine spatial-temporal data on plant electricity generation, air quality standard exceedance days, and population characteristics available from environmental justice screening tool CalEnviroScreen 2.0 to determine where emissions reductions may have the greatest marginal benefit. This screening approach can inform grid siting decisions, such as storage in lieu of peaker plants in high impact regions, or dispatch protocol, such as triggering demand response instead of peaker plants on poor air quality days.