Seasonal variations in residential and commercial sector electricity consumption in Hong Kong

We present the energy use situation in Hong Kong from 1979 to 2006. The primary energy requirement (PER) nearly tripled during the 28-year period, rising from 195,405 to 566,685 TJ, about two-third of which was used for electricity generation. The residential and commercial sectors are the two largest electricity end-users with an average annual growth rate of 5.9% and 7.4%, respectively. The monthly consumption in these two sectors shows distinct seasonal variations mainly due to changes in the air-conditioning requirements, which are affected by the prevailing weather conditions. Principal component analysis of five major climatic variables—dry-bulb temperature, wet-bulb temperature, global solar radiation, clearness index and wind speed—was conducted. Measured sector-wide electricity consumption was correlated with the corresponding two principal components determined using multiple regression technique. The regression models could give a very good indication of the annual electricity use (largely within a few percents), but individual monthly estimation could differ by up to 24%. It was also found that the climatic indicators determined appeared to show a slight increasing trend during the 28-year period indicating a subtle, but gradual change of climatic conditions that might affect future air-conditioning requirements.     

US power plant location and fuel mix: Opportunities for electricity exporting regions

There is considerable discussion in the USA concerning electricity trade between regions. The transmission system was not designed to accommodate interregional power trade, but regional differences in reserve margins and power generation costs have encouraged power trade to occur. Utilities with abundant coal-fired capacity in the Appalachians and Midwest are calling power to east ctilities who wish to restrict their oil burn. Interregional power trade has benefitted both buyer and seller. Many in electricity exporting regions view electricity exports as a source of revenue and are taking steps to maintain or increase power sales.     

Engineering and optimization approaches to enhance the thermal efficiency of coal electricity generation in China

China has made improving the thermal efficiencies of its coal-fired power plants a national priority. Official data show that the average thermal efficiency was enhanced from 31.3% in 2000 to 33.2% in 2005 and 36.9% in 2010. This paper aims to assess the validity of China's claimed improvement, examine major responsible factors, and identify future improvement opportunities. Recognizable factors can account for about 80% of the reported progress in the 10th Five-Year Plan (2001–2005) and about 85% in the 11th (2006–2010) to largely verify the reported progress. Engineering approaches—especially replacing inefficient power units with more efficient ones—are the largest contributing factors, while optimization approaches—particularly electricity dispatch—remains inefficient in China. In 2010, the explainable efficiency improvement might have avoided around 500 million tons of CO₂ emissions. In comparison, although the United States was fairly static with most of its coal-fired power plants seriously outdated, it has more efficient electricity dispatch. In China's ongoing 12th Five-Year Plan (2011–2015), better dispatch patterns could be more important as opportunities for improvement through engineering approaches have been largely exhausted.     

Modeling Lebanon’s electricity sector: Alternative scenarios and their implications

This paper is concerned with modeling possible future paths for Lebanon’s electricity future and evaluating them. The baseline scenario (BS) reflects the business-as-usual state of affairs and thus describes the most likely evolution of the power sector in the absence of any climate change-related or other policies. Two alternative scenarios are examined in contrast to the BS; the renewable energy scenario (RES) and the natural gas scenario (NGS). Using the Long range Energy Alternatives Planning System (LEAP) software we conduct a full-fledged scenario analysis and examine the technical, economic, and environmental implications of all scenarios.From an economic standpoint as well as from an environmental perspective both alternative scenarios are superior to the baseline. Hence, the results of the simulation show that the alternative scenarios are more environmentally and economically attractive than the BS. They would help Lebanon meet its social, environmental, and economic development goals, while at the same time providing other unquantifiable benefits that are discussed further in the paper. Anticipated barriers to the shift in energy mix from conventional sources to renewable energy sources are also presented and discussed     

Estimation of residential electricity demand in Hong Kong under electricity charge subsidies

Over the past decade, the Hong Kong (HK) government provided electricity charges subsidies for residential accounts to alleviate the burden of inflation and, later, the burden of economic downturn. In this study, we estimate an econometric model of residential electricity demand and test the existence of a stable long-run relationship for the period 1980–2016, while accounting for the relief measures set out by the HK government since 2008. Empirical results suggest that there exists a long-run relationship among residential electricity consumption, electricity price, income per capita, and weather variables (temperature or cooling degree days). In the absence of electricity charge subsidies, the demand is found to be both price and income inelastic. On the other hand, HK's residential electricity consumers are unresponsive to price and income changes when electricity subsidies are in place. Following its new carbon reduction plan, HK is gradually phasing out coal for electricity generation to replace it mainly with natural gas. Our results suggest that new residential electricity charge subsidies can lessen the effectiveness of6 climate policies aimed at reducing electricity consumption through increases in the electricity price.     

Risk perception,trust and public engagement in nuclear decision-making in Hong Kong

The extent to which nuclear energy can be a feasible energy option has re-emerged as a subject of widespread debate following the Fukushima accident in Japan. However, relatively little is known about how public inputs can improve nuclear decision-making. This paper aims to provide a better understanding of public opinions regarding nuclear energy by examining its risk perception, trust and public engagement dimensions. Based on a survey of Hong Kong residents (n=509), we make some observations. Firstly, we offer empirical evidence that affirms the theoretical connections between risk perception, trust, and public engagement in the context of nuclear energy. Secondly, our logistic regression analysis indicates that demographics, trust, and perceptions of the efficacy of public engagement are factors explaining perceptions of greater risks and nuclear opposition. Thirdly, our conceptual model sheds light on the complexity of the trust concept, and specifies aspects of trust that are influential in the contexts of risk perception and nuclear choices. Our findings suggest that the Hong Kong government must ensure trust building receives prominent attention in nuclear decision-making, and that it should avoid excessive reliance on the business sector and should assume a key role for itself in enhancing trust in nuclear decision-making.     

Problems of hydrogen application in space power plants and power propulsion plants

Application of hydrogen is a necessary condition to achieve acceptable power and overall-dimensional characteristics of space power and propulsion plants. Some functional elements as part of the plants require protection from hydrogen, which is provided by construction and technological preparation of materials. For subsequent improvement of the plants, it is necessary to look for materials with low hydrogen penetrability in the temperature range of 800–2500 K and also for protective coatings on graphite for conditions of thermocycling in the range of 300–2100 K.     

PRA in the nuclear sector: Quantifying human error and human malice

Regardless of the regulatory style chosen (‘command and control’ or ‘functional’) a vital prerequisite for coherent safety regulation in the nuclear power industry is the ability to assess accident risk. In this paper we present a critical analysis of current techniques of probabilistic risk analysis applied in the industry, with particular regard to the problems of quantifying risks arising from, or exacerbated by, human risk and/or human error     

A dynamic equilibrium of electricity consumption and GDP in Hong Kong: An empirical investigation

Public debates on electricity policy in Hong Kong focus on the regulation regime but seldom discuss the macroeconomic impact. In this paper, we use the novel dataset on electricity consumption and report the following findings: (1) there is a long run equilibrium relationship between real GDP and electricity consumption; (2) a one-way causal effect exists from electricity consumption to real GDP; (3) a significant adjustment process occurs when equilibrium is interrupted; (4) there exists possible structural change in the relationship between electricity consumption and economic activities in 1990s.     

Future regional nuclear fuel cycle cooperation in East Asia: Energy security costs and benefits

Economic growth in East Asia has rapidly increased regional energy, and especially, electricity needs. Many of the countries of East Asia have sought or are seeking to diversify their energy sources and bolster their energy supply and/or environmental security by developing nuclear power. Rapid development of nuclear power in East Asia brings with it concerns regarding nuclear weapons proliferation associated with uranium enrichment and spent nuclear fuel management. This article summarizes the development and analysis of four different scenarios of nuclear fuel cycle management in East Asia, including a scenario where each major nuclear power user develops uranium enrichment and reprocessing of spent fuel individually, scenarios featuring cooperation in the full fuel cycle, and a scenario where reprocessing is avoided in favor of dry cask storage of spent fuel. The material inputs and outputs and costs of key fuel cycle elements under each scenario are summarized.     

Efficient utilization of waste heat from molten carbonate fuel cell in parabolic trough power plant for electricity and hydrogen coproduction

Direct steam generating parabolic trough power plant is an important technology to match future electric energy demand. One of the problems related to its emergence is energy storage. Solar-to-hydrogen is a promising technology for solar energy storage. Electrolysis is among the most processes of hydrogen production recently investigated. High temperature steam electrolysis is a clean process to efficiently produce hydrogen. In this paper, steam electrolysis process using solar energy is used to produce hydrogen. A heat recovery steam generator generates high temperature steam thanks to the molten carbonate fuel cell's waste heat. The analytical study investigates the energy efficiency of solar power plant, molten carbonate fuel cell and electrolyser. The impact of waste heat utilization on electricity and hydrogen generation is analysed. The results of calculations done with MATLAB software show that fuel cell produces 7.73 MWth of thermal energy at design conditions. 73.37 tonnes of hydrogen and 14.26 GWh of electricity are yearly produced. The annual energy efficiency of electrolyser is 70% while the annual mean electric efficiency of solar power plant is 18.30%.The proposed configuration based on the yearly electricity production and hydrogen generation has presented a good performance.     

Comprehensive evaluation of coal-fired power plants based on grey relational analysis and analytic hierarchy process

In China, coal-fired power plants are the main supplier of electricity, as well as the largest consumer of coal and water resources and the biggest emitter of SO_x, NO_x, and greenhouse gases (GHGs). Therefore, it is important to establish a scientific, reasonable, and feasible comprehensive evaluation system for coal-fired power plants to guide them in achieving multi-optimisation of their thermal, environmental, and economic performance. This paper proposes a novel comprehensive evaluation method, which is based on a combination of the grey relational analysis (GRA) and the analytic hierarchy process (AHP), to assess the multi-objective performance of power plants. Unlike the traditional evaluation method that uses coal consumption as a basic indicator, the proposed evaluation method also takes water consumption and pollutant emissions as indicators. On the basis of the proposed evaluation method, a case study on typical 600 MW coal-fired power plants is carried out to determine the relevancy rules among factors including the coal consumption, water consumption, pollutant, and GHG emissions of power plants. This research offers new ideas and methods for the comprehensive performance evaluation of complex energy utilisation systems, and is beneficial to the synthesised consideration of resources, economy, and environment factors in system optimising and policy making.     

和平水电站厂用电设计

依据和平水电站厂用负荷的容量大小、用途性质、重要程度、分布地点及运行方式 ,设计的厂用电接线简单、可靠、灵活、操作维护方便、经济上合理。为小型水电站厂用电设计提供了有益的经验。     

Green electricity production with living plants and bacteria in a fuel cell

The world needs sustainable, efficient, and renewable energy production. We present the plant microbial fuel cell (plant-MFC), a concept that exploits a bioenergy source in situ. In the plant-MFC, plants and bacteria were present to convert solar energy into green electricity. The principal idea is that plants produce rhizodeposits, mostly in the form of carbohydrates, and the bacteria convert these rhizodeposits into electrical energy via the fuel cell. Here, we demonstrated the proof of principle using Reed mannagrass. We achieved a maximal electrical power production of 67 mW m⁻² anode surface. This system was characterized by: (1) nondestructive, in situ harvesting of bioenergy; (2) potential implementation in wetlands and poor soils without competition to food or conventional bioenergy production, which makes it an additional bioenergy supply; (3) an estimated potential electricity production of 21 GJ ha⁻¹ year⁻¹ (5800 kWh ha⁻¹ year⁻¹) in Europe; and (4) carbon neutral and combustion emission-free operation. Copyright © 2008 John Wiley & Sons, Ltd.     

Towards a competitive market for electricity and consumer choice in the Indian power sector

The initial phase of reforms in the Indian power sector was primarily aimed at bringing regulatory reforms and unbundling of the vertically integrated State Electricity Boards (SEBs). Enactment of the Electricity Act 2003 led to deepening of the reform process by dismantling this monopoly in the power sector. Primary issues emerging on account of transition from a single-buyer model to a multi-buyer multi-seller model include, among others, policy and regulatory initiatives related to open access, power exchanges, and transmission allocation and its pricing. The paper provides an overview of the status of competition in various segments of the power sector. It also reviews the phased program for open access outlined by various State Electricity Regulatory Commissions, including their status and impact on competition. The paper highlights a number of residual issues for the wholesale and retail competition, and also discusses the approach to address the same. These include liberalization of fuel markets, market monitoring, unbundling of retail tariffs, universal service obligation, supplier of last resort and demand response.     

Impact of climate change on commercial sector air conditioning energy consumption in subtropical Hong Kong

Past and future trend of electricity use for air conditioning in the entire commercial sector in subtropical climates using 1979–2008 measured meteorological data as well as predictions for 2009–2100 from a general circulation model (MIROC3.2-H) was investigated. Air conditioning consumption showed an increasing trend over the past 30 years from 1979 to 2008. Principal component analysis (PCA) of measured and predicted monthly mean dry-bulb temperature, wet-bulb temperature and global solar radiation was conducted to determine a new climatic index Z for 1979–2008 and future 92 years (2009–2100) based on two emissions scenarios B1 and A1B (low and medium forcing). Through regression analysis, electricity use in air conditioning for the 92-year period was estimated. For low forcing, average consumption in 2009–2038, 2039–2068 and 2069–2100 would be, respectively, 5.7%, 12.8% and 18.4% more than the 1979–2008 average, with a mean 12.5% increase for the entire 92-year period. Medium forcing showed a similar increasing trend, but 1–4% more. Standard deviations of the monthly air conditioning consumption were found to be smaller suggesting possible reduction in seasonal variations in future years.     

Accumulation of nuclear spent fuel from UK power stations

In the absence of a reprocessing industry able to deal with large quantities of irradiated nuclear fuel, it is expected that the bulk of the oxide spent fuel discharged from nuclear reactors will be stored for some decades. In this report the rate of accumulation of spent fuel in the UK and the proportion of its plutonium content is assessed. It is shown that the plutonium content of the metal spent fuel arising from Magnox stations alone should be sufficient to fuel a modest fast breeder programme of 1–2 GW_e well into the next century. As there is an established reprocessing industry for metal fuel, it is argued that reprocessing of oxide fuel need not take place until uncertainties over its cost and necessity are resolved.     

An experimental study of membranes for capturing water vapor from flue gas

This paper has made an active attempt on recovering water from flue gas using membranes. The properties of SPEEK/PES, a hydrophilic composite hollow fiber membrane, are studied in the present paper using experimental analyses of thermal gravimetric, differential scanning calorimetry and scanning electron micrograph. Experimental results show that SPEEK/PES composite hollow fiber membranes have excellent thermal stability and mechanical properties in flue gas. An experiment with using simulated flue gas (N₂/water vapor mixed) is carried out to study the impact of sweep gas flow rate and feed gas temperature on the membrane module properties. The results indicate that the water recovery rate increases with the temperature increasing from 40 °C to 70 °C. The application of capturing the water in flue gas is very attractive, and it will provide a new way of saving energy and alleviating the haze.     

Social and engineering determinants and their equity implications in residential electricity use

Energy conservation may occur because of either economic constraints or voluntary changes in values and lifestyle, with quite different social welfare implications. We examine the determinants of summer electricity use in single-family dwellings. Income and household size strongly affect energy use, while factors related to values and lifestyle are less important. A causal model approach is used to show how the social variables are related to energy use through intervening engineering/hardware variables.     

Performance based regulation of the electricity supply industry in Hong Kong: An empirical efficiency analysis approach

This paper presents an empirical efficiency analysis approach to analyze the efficiency and performance of utilities and its effects on prices under the price-cap performance based regulation (PBR) model. A data envelopment analysis (DEA)-like frontier-based method is used to compute the total factor productivity with the Malmquist productivity index. Results of case studies support the use of the approach to account for the relation of the X-factor and the PBR model on the two power utilities in Hong Kong's electricity supply industry.