Past as Prologue? Understanding energy use in post-2002 China

From 2002 to 2009, China's energy use nearly doubled, making it the world's largest emitter of carbon dioxide more than a decade ahead of forecasts. Why did energy use in China rise so rapidly after 2002? Using index decomposition analysis, we find that the vast majority of growth in energy consumption in China over the 2000s was due to GDP growth, with a small but important amount due to structural change as a result of China's emergence as a net metals exporter. Changing prices and data anomalies make energy intensity and structural change appear to be more important drivers of energy consumption than they actually were; the infamous reversal in energy intensity in China from 2002 to 2004 may simply be an artifact of difficulties in accurately deflating value added. About half of the growth in energy consumption in China from 2002 to 2007 was driven by heavy industry. Using structural decomposition analysis, we find that growth in heavy industrial output was due primarily to growth in construction and equipment investment, with a small amount due to an increase in net metal exports. In tandem, these two findings suggest that the primary driver of energy consumption in China after 2002 was an acceleration of the country's investment-dominated model of GDP growth. Without rebalancing the economy toward consumption, there are limits to what improvements in energy conversion efficiency and end use energy efficiency can achieve in moderating growth in China's energy use.     

Does electricity price matter for innovation in renewable energy technologies in China?

Though the development of renewable energy is rapid, innovation in renewable energy technologies is relatively weak due to the late commencement of renewable energy in China. In addition, renewable energy is mainly introduced into the supply mix of electricity generation, which increases the costs of electricity generation. Higher electricity price will make renewable energy more competitive and call forth renewable energy technological innovation. Based on FMOLS and DOLS models, as well as PMG model, this paper investigates the induced long and short run effects of electricity price, funding support, and economic growth on innovation in renewable energy technologies at the provincial level in China during the period 2006–2016. The Conclusions drawn were: (1) R&D expenditure and economic growth have positive impacts on innovation in renewable energy technologies in the long and short run; (2) Electricity price only has a long run effect on patenting in renewable energy technologies; (3) In the long run, a 1% increase in electricity price can lead to a 0.7825%–1.0952% increase in the patent counts of renewable energy technologies; (4) Electricity pricing system in China does not play any role in driving renewable energy technological innovation in the short run.     

A study of residential energy use in Hong Kong by decomposition analysis, 1990–2007

Energy end-use for all sectors (commercial, residential, transport, industrial) in Hong Kong shows that the residential share increased from 14.2% in 1990 to 18.1% in 2007, such share increase has prompted the authors to analyze the issue. The Divisia decomposition analysis is used to evaluate the respective contributions of changes in (1) the number of households, (2) share of different types of residential households, (3) efficiency gains, and (4) climate condition to the energy use increase. The analysis reveals that the major contributor was the increase of the number of households, and the second major contributor was the intensity effect. As expected, the segment of the private housing (apartments) was becoming less energy efficient. In addition, it is interesting to note that the energy end-use per household in the segment of government rental subsidized housing (apartments) was decreasing. The decrease of the household income in this segment may be one of the reasons while statistics showing that the number of low-income household was increasing and leaning towards the lowest income classes. On the other hand, it is believed that people tend to consume more energy to obtain a quality life characterized with comfortable living with the growth of economy and improvement of living standard. However, Hong Kong becomes a counterexample since 2004. Therefore, changing the residents’ behavior may not be an effective tactic for reducing energy consumption.     

Changes in energy requirements of the residential sector in India between 1993–94 and 2006–07

A substantial amount of primary and secondary energy is consumed by the residential sector. Residential energy consumption includes energy required for construction activity and household consumption. Hence there is a need to quantify energy consumption, its significance and causes. Calculating energy intensity of goods and services is the first step towards quantifying the causes. This research is based on the 115 sector classification input–output tables for India, for 1993–94, 1998–99 and 130 sector classification input–output tables for 2003–04 and 2006–07. Energy intensity of sectors related to household consumption has been calculated to analyze the trend between 1993–94 and 2006–07. Indirect energy requirements of Indian households have been assessed in this study from calculations of total primary energy intensity along with private final consumption expenditure. Results indicate that energy consumption has increased for all categories except “medical care and hygiene”. Percentage increase in indirect primary energy consumed by households is maximum for “house building” and “recreation” categories. Finally a complete decomposition analysis of indirect primary energy consumed by households has been carried out based on changing structural composition of the private final consumption expenditure, energy intensity patterns, per capita expenditures on energy and population.     

Solar–hydrogen energy system for Egypt

A model for a solar–hydrogen energy system for Egypt has been developed by obtaining relationships for and between the main energy and energy related parameters. The magnitude and trends of the parameters, with and without hydrogen introduction, have been investigated over a period of time. The results indicate that the fossil fuel resources in Egypt could be exhausted within one to two decades. They also indicate that adopting the solar–hydrogen energy system would extend the availability of fossil fuel resources, reduce pollution, and establish a permanent energy system for Egypt. They show that Egypt could become an exporter of hydrogen. © 1999 International Association for Hydrogen Energy.     

Feasibility study for a standalone solar–wind-based hybrid energy system for application in Ethiopia

The aim of this paper is to investigate the possibility of supplying electricity from a solar–wind hybrid system to a remotely located model community detached from the main electricity grid in Ethiopia. The wind energy potential of four typical locations has been assessed in a previous article. The solar potential has also been investigated and the results are presented in detail in an accompanying article awaiting publication. For one of the sites, Addis Ababa, the results of the investigation are given here in detail. For the other sites, the results are given as sensitivity diagrams only. Based on the findings of the studies into energy potential, a feasibility study has been carried out on how to supply electricity to a model community of 200 families, which comprises 1000 people in total. The community is equipped with a community school and a health post. The electric load consists of both primary and deferrable types and comprises lighting, water pumps, radio receivers, and some clinical equipment. A software tool, Hybrid Optimization Model for Electric Renewables (HOMER) is used for the analysis. The result of the analysis is a list of feasible power supply systems, sorted according to their net present cost. Furthermore, sensitivity diagrams, showing the influence of wind speeds, PV costs, and diesel prices on the optimum solutions are also provided.     

How does tax system on energy industries affect energy demand,CO2 emissions,and economy in China?

Energy savings and CO₂ emission reduction have become a major issue in recent years. Taxes on energy production sectors may be an effective way to save energy, reduce CO₂ emissions, and improve environmental quality. This paper constructs a dynamic recursive Computable General Equilibrium (CGE) model to analyze the impact of the energy tax on energy, economy, and environment from the perspective of tax rates and tax forms (specific tax and ad valorem tax). The results show that adjusting the tax system and the tax rate has important implications for energy conservation while having minor impacts on the output of other industries. The impact of an increasing energy tax on the energy demand is greater than the impact on sectoral output, indicating that energy efficiency will be increased to some extent. The CO₂ reduction will increase over time when an ad valorem tax is implemented on enterprises. We found that ad valorem tax has greater elasticity of economic output, energy demand, and CO₂ emission reduction. The results support the direction of China's resource tax reform. However, we argue that it is better to increase the tax rate relatively and relax the control on energy prices so that energy efficiency will increase.     

Developments of energy in EU–unlocking the wave energy potential

The New Entrance Reserve (NER300) is one of the leading mechanisms used for the application and promotion of clean energy projects. In this context, this study aims to investigate the evolution of wave energy projects within the first and second call of NER300. Furthermore, the study tries to identify the reasons of successful applications through an estimation analysis of energy production, avoided emission and energy security. Milder resources contain ‘hidden’ opportunities for wave energy, with lower expenditure and capacity factors equivalent and even over 20%. Lower extreme events indicate that associated installation costs can be considered reduced, thus the potential cost of energy may act as a positive driver for future development. The results of the study argue that there are regions with ‘hidden’ opportunities that can accelerate proof-of-concept and enhance viability for wave energy.     

Energy embodied in the international trade of China: An energy input–output analysis

Growing international trade has not only positively affected the People’s Republic of China’s (China’s) economic development, but also expanded the exportation of energy embodied in goods during their production. This energy flow out will pose risks to China’s rational utilization of natural resources as well as environmental protection. In this paper, we evaluate the energy embodied in goods produced in China during 1992–2005 and use input–output structural decomposition analysis to identify five key factors causing the changes of energy embodied in exports. (Direct primary energy efficiency, primary energy consumption structure, structure of intermediate inputs, structure of exports, and scale of exports.) For the three sub-periods of 1992–1997, 1997–2002, and 2002–2005, results show that China is a net exporter of energy, and the energy embodied in exports tends to increase over time. The expanding total volume of exports and increasing exports of energy-intensive goods tend to enlarge the energy embodied in exports within all three sub-periods, but these driving forces were offset by a considerable improvement of energy efficiency and changes in primary energy consumption structure from 1992 to 2002 and the effects of structure of intermediate input only in the sub-period from 1992 to 1997. From 2002 to 2005, the sharp augmentation of energy embodied in exports was driven by all the five factors. Our research has practical implications for the Chinese economy. Results of this study suggest that the energy embodied in trade should receive special attentions in energy policies design to limit the energy resource out-flow and pollution generation.     

The development and application practice of wind–solar energy hybrid generation systems in China

China is the largest developing country in the world. At present, more and more energy demand gives immense pressure to Chinese government. The inappropriate energy structure must be improved by Chinese government in order to achieve the sustainable development of economy and society. Development and application of renewable energy, such as wind energy, solar energy, biomass energy, etc., have been regarded by the government and the local people in the past 10 years, and more and more actual examples have been established, which are supported by government and plants in China. It is well known that there are abundant wind and solar resources in China. This paper presents the distribution zone and development and application practice status in China. However, a common drawback is existing in the stand-alone wind energy and solar energy generating power system, which is the unpredictable output electric power, and the output power depends on the unpredictable weather and climatic changes. Fortunately, the wind–solar hybrid generation system can partially overcome the problems. The conventional structure and key technology of stand-alone wind–solar hybrid generating system, the current status and outlook of wind–solar hybrid energy system are presented in the paper, for example, the city road lighting system, distributed generation, photovoltaic (PV) water pumping for irrigation, etc. At the end, the policies and laws of China central government and local governments are described, and the development barriers and recommendations are introduced.     

Dutch sectoral energy intensity developments in international perspective, 1987–2005

This paper makes use of a new dataset to investigate energy intensity developments in the Netherlands over the period 1987–2005. The dataset allows for a comparison with 18 other OECD countries. A key feature of our analysis is that we combine a cross-country perspective with a high level of sectoral detail, covering 49 sectors. Particularly innovative is our evaluation of energy intensity developments in a wide range of Service sectors. We find that across sectors, energy intensity levels in the Netherlands on average decreased only marginally, and increased in Services. This performance is in general worse than the OECD average, especially between 1987 and 1995. Changes in the sectoral composition of the economy play an important role in explaining aggregate trends. In the Manufacturing sector, about half of the efficiency improvements were undone by a shift towards a more energy-intensive industry structure. In contrast, in the Service sector efficiency decreased, which was undone for about one third by a shift towards a less energy-intensive sector structure.     

Climatic considerations in school building design in the hot–humid climate for reducing energy consumption

Energy-conscious design of school buildings can contribute to significant energy savings and improve the students’ learning environment. The purpose of this research is to formulate design recommendations for school buildings in the hot–humid climatic zone and assess the influence of different design variables on their energy consumption. A base-case classroom was constructed by taking commonly used values for each design variable. Using computer simulation techniques, these variables were modified one by one to find the value that minimized energy consumption, while keeping thermal and visual comfort in the room. Based on these tests, the recommended value for each design variable to achieve a high performance classroom, was determined. Comparative tests were done to determine which variables have greatest impact on the energy consumption and thermal comfort in the classroom, and how their absolute influence depends on the order of implementation of each improvement. A complex interdependence among the design variables was found, but strong conclusions for energy savings could still be reached.     

Richer and healthier,but not Greener? Choices concerning household energy use in India

India is among the world lowest per capita greenhouse gas (GHG) emitters, but rapid increases are expected. At the same time, World Health Organization (WHO) estimates show that 424,000 die prematurely in Indian households each year from air pollution exposure due to solid fuel use. We analyze GHG emissions and health through three policy scenarios for household energy, using projections for population, income and urbanization. In policy scenarios called Business as Usual (BAU), Improved Health, and Green Future, projected per capita household GHG emissions in 2026 increase by 169%, 164% and 139%, respectively, compared to 2001, whereas household mortality rates decrease by 45%, 67% and 45%, respectively. Due to income growth and urbanization, an increase in GHG emissions is likely inevitable, but can be slowed. For health, in contrast, improvements are expected and can be expanded.     

Design and optimization of an air heating solar collector with integrated phase change material energy storage for use in humidification–dehumidification desalination

Compared to solar water heaters, high-temperature solar air heaters have received relatively little investigation and have resulted in few commercial products. However, in the context of a humidification–dehumidification (HD) desalination cycle, air heating offers significant performance gains for the cycle. Heating at a constant temperature and constant heat output is also important for HD cycle performance. The use of built in phase change material (PCM) storage is found to produce consistent air outlet temperatures throughout the day or night. In this study, the PCM has been implemented directly below the absorber plate. Using a two dimensional transient finite element model, it is found that a PCM layer of 8 cm below the absorber plate is sufficient to produce a consistent output temperature close to the PCM melting temperature with a time-averaged collector thermal efficiency of 35%. An experimental energy storage collector with an 8 cm thick PCM layer was built and tested in a variety of weather and operating conditions. Experimental results show strong agreement with model in all cases.     

China's oil use, 1990–2008

Over the past two decades, China's oil demand has risen steeply. In 1990, it was only about 25% higher than that of 1978, the year economic reform was introduced. By 2008, it had reached 396.0 million tons, roughly four times the 1978 level, making China the second largest oil user worldwide. The country became a net oil importer in 1993, and between 1993 and 2008, its net import dependency—a yardstick for energy security—soared from 7.5% to 50.0%. China's increased demand for oil has made the country a global energy player of critical importance. Although the literature on the global implications of China's oil use has proliferated, relatively few studies have attempted to examine “how China uses oil.” Hence, this study covers every oil-consuming facility and sector in China, exploring the patterns of, and factors involved in, oil demand by power plants, oil refineries, heat plants and, gas-works, and industrial, transport, agricultural, household and commercial sectors. It concludes that in virtually all sectors in China, oil demand will grow, with transport and industry leading the way.     

Climbing the energy ladder or diversifying energy sources? The continuing importance of household use of biomass energy in urbanizing communities in Northeast Thailand

Following the energy ladder model, the role of biomass energy will diminish and even disappear as rural communities become more urbanized. However, the alternative fuel stacking model suggests that, as households become more urbanized, they diversify their energy sources while continue using firewood and charcoal. This study aimed to assess the extent to which biomass energy still plays an important role as a source of energy for household consumption across the urbanization spectrum of communities. Three villages in Khon Kaen province in Northeast Thailand representing the rural, suburban and urban communities were selected for study. Data were collected on energy uses at household level using a formal questionnaire survey along with field observation and field measurement. The results showed that total household energy consumption increased with urbanization. The absolute quantity of biomass energy used slightly increased when going from rural (5.52 GJ caput⁻¹ y⁻¹) to suburban (6.06 GJ caput⁻¹ y⁻¹) but greatly decreased for urban community (1.98 GJ caput⁻¹ y⁻¹), while the relative share declined with greater urbanization, being 46.2, 37.4 and 10.2% for the rural, suburban and urban communities, respectively. Both firewood and charcoal were used primarily for cooking, with a small amount used for home industry. It was concluded that, although the share of biomass energy in household energy portfolios does decline relative to modern energy sources in the course of urbanization, as predicted by the energy ladder model, there is no sharp discontinuity in utilization of energy sources between communities at different stages of urbanization and biomass continue to be an important component of household energy portfolios in all communities, supporting the fuel stacking model. It appears likely that biomass will remain an important source of household energy in Thailand for an extended period.     

Temperature-explicit formulation of energy equation for thermal–hydraulic analyses

A temperature equation which is derived from an enthalpy transport equation by using an assumption of a constant specific heat is very attractive for analyses of heat and fluid flows. It can be used for an analysis of a solid–fluid conjugate heat transfer, and it does not need a numerical method to obtain temperature from a temperature–enthalpy relation. But its application is limited because of the assumption. A new method is derived in this study, which is a temperature-explicit formulation of the energy equation. The enthalpy form of the energy equation is used in the method. But the final discrete form of the equation is expressed with temperature. The discretized equation from the temperature-explicit formulation can be used for a heat transfer analysis in a solid–fluid coupled region without any special treatment at the solid–fluid interface. And it can be applied for multiphase flows with a real gas effect. It is found by numerical tests in this study that the proposed method is very efficient and as accurate as the standard enthalpy formulation.