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1.
Light duty vehicles, i.e. passenger cars and light trucks, account for approximately half of global transportation energy demand and, thus, a major share of carbon dioxide and other emissions from the transport sector. Energy consumption in the transport sector is expected to grow in the future, especially in developing countries. Cars with alternative powertrains to internal combustion engines (notably battery, hybrid and fuel-cell powertrains), in combination with potentially low carbon electricity or alternative fuels (notably hydrogen and methanol), can reduce energy demand by at least 50%, and carbon dioxide and regulated emissions much further. This article presents a comparative technical and economic assessment of promising future fuel/vehicle combinations. There are several promising technologies but no obvious winners. However, the electric drivetrain is a common denominator in the alternative powertrains and continued cost reductions are important for widespread deployment in future vehicles. Development paths from current fossil fuel based systems to future carbon-neutral supply systems appear to be flexible and a gradual phasing-in of new powertrains and carbon-neutral fluid fuels or electricity is technically possible. Technology development drivers and vehicle manufacturers are found mainly in industrialised countries, but developing countries represent a growing market and may have an increasingly important role in shaping the future.  相似文献   

2.
Forestry and energy policies in Malawi place the blame for the country's high rate of deforestation on the demand for woodfuel. The government has been involved in a range of questionable supply-side initiatives, as well as in a number of interventions in woodfuel markets, with the objective of slowing rates of deforestation. It seeks to encourage farmers to grow woodfuel to meet market demands, and has provided subsidies to do so. The Forest Department has kept prices for firewood from its plantations low, both in order to discourage the market for wood from free resources and because of concerns about the impact of high producer prices on the urban poor. In doing so, the government is less able to rely on the market to provide producers with the incentive to plant trees to meet market demands. In any event, the market accounts for a relatively small proportion of total woodfuel demand. Policies do not distinguish between rural household demands and the specific market demands which are having the greatest impact on deforestation: woodfuel for urban markets, for tobacco curing, and for small industries. These, coupled with the expansion of the estate sector, have had afar greater impact on woodland clearance than rural, subsistence woodfuel demands. Rural household energy demands need to be addressed from a much broader perspective which considers the household's larger needs for tree based products or outputs: income, food, fibre, fodder, soil fertility, as well as for fuel .  相似文献   

3.
Current projections estimating world population growth read in conjunction with corresponding projections of increased world energy consumption, point to electricity as the cleaner fuel of the future, especially because of its high efficiency and low levels of pollution. Due mostly to the fact that the electrical end-use devices are considerably more efficient than those using other forms of energy, most developed countries show decreasing curves of energy intensity as technologies become more sophisticated and shift over to increased reliance on electricity. It is therefore argued in this article that a gradual shift away from fossil fuels to electricity is a promising possibility to bring down global air pollution and emissions of greenhouse gases to acceptable levels. Examples are given of greater efficiency achieved by electrification. Overall gains in energy efficiency from the change over from fossil fuels to electricity, are possible even in situations where the electricity is generated by fossil fuel combustion, despite the loss of primary energy in the conversion process. The article also presents electricity generating projects designed for developing countries and countries with economies in transition. The generation of electricity from the combustion of renewable sources (biomass waste), fossil fuels, and other innovative methods are outlined.  相似文献   

4.
This article discusses the various phases in petroleum product consumption in India from 1960 to 1996, and analyses the changes in consumption patterns. Consumption is growing rapidly although the intensity of petroleum use and the proportion of petroleum in the overall secondary energy consumption is actually on the decline, especially since the mid-1980s. The proportion of middle distillates in total consumption, especially HSD (High Speed Diesel) which accounts for 45%, is very high mainly because of distortions caused by Government subsidies. The article also analyses expected demand for petroleum products up till the year 2010, emphasizing the need to address the particularly fast growing demand for middle distillates. Further, the article discusses various policy issues pertaining to upstream and downstream activities of oil and gas supply, and emphasizes the need for increased investment in exploration and development, better management of existing reserves, rationalization of pricing policies and the creation of modern infrastructure to meet growing needs.  相似文献   

5.
The late 1980s saw an astonishing turnaround in the Asian oil market. After years of stagnation, three main factors - economic dynamism, lower oil prices and reduced government regulation of the market - resulted in a consumption surge that surprised even those analysts who had predicted such a recovery. The chronically capacity-surplus refining industry saw a leap in profitability, and new construction began. Rapid demand growth spread from the middle distillates to such formerly depressed products as gasoline and fuel oil, and naphtha markets began to expand again as the petrochemical industry resumed rapid growth. At the same time that demand has been rising and demand patterns have been shifting, other changes have begun. A new environmental awareness has taken root in Asia, and new environmental standards are being set almost daily, not only in the richer countries of East Asia, but also in many of the region's developing nations. Unfortunately, traditional sources of low-sulphur oil for power generation may be limited in the coming decade. Despite many new discoveries within the region, Asian crude availability is shrinking, both in terms of availability on the international market and in terms of percentage contribution to regional oil demand. After years of decreasing reliance, the region will face rapid increases in imports from the Persian Gulf in the 1990s.  相似文献   

6.
In Liberia, as in many developing countries, electrification of towns and cities throughout the country has long been a major development goal. However, fuel expenditures by the Liberian Electricity Corporation (LEC) for its rural public stations represent a major and growing burden on the financially hard-pressed utility. In this paper we evaluate the economics of supplying wood to rural electric power plants utilizing different sources of feedstock. We also evaluate the cost implications of differences in wood supply requirements based on the use of steam or gasifier technology, and from variation in plant utilization level.
The wood supply we consider as sources are: (1) retired rubber trees; (2) the harvesting of secondary-growth forest just before the land is returned to temporary cultivation; (3) the establishment of commercial short-rotation wood energy plantations; and (4) adding to the system of shifting agriculture the planting of fast-growing wood species. The results indicate that wood can probably be supplied under a wide range of supply and demand conditions for US$1.00–1.70 per GJ. We estimate that wood steam plants can generate power for about $0.09-0.14 per kWh and gasifier plants for $0.10-0.18 per kWh. These costs are well below the present cost of oil-based rural electric power generation in Liberia (about $0.20–0.27 per kWh).  相似文献   

7.
The iron and steel industry plays a fundamental role in a country's national economy, especially in developing countries. China is the largest iron ore consumption market in the world. However, because of limited domestic iron ore resources, a large proportion of iron ore is imported from other countries. Faced with the conflict between the iron ore supply shortage and the growing demand, it is necessary for the government to predict imports and total consumption. This paper develops a high-precision hybrid model based on grey prediction and rolling mechanism optimized by particle swarm optimization algorithm. We use the China Statistical Yearbook (1996–2011) as our database to test the efficiency and accuracy of the proposed method. According to the experimental results, the proposed new method clearly can improve the prediction accuracy of the original grey model. Future projections have also been done for iron ore imports and total consumption in China in the next five years.  相似文献   

8.
Over the last decades, oil consumption in the developing countries hus been increasing rapidly. Road transport has accounted for most of this increase in demand. It is the thesis of this paper that future growth in oil demand in developing countries will occur mainly in the road transport sector and that this growth will be surprisingly strong. Estimated income and price elasticities for several developing countries are presented and forecasts for oil consumption in road transport in the developing countries up to 2010 are given.  相似文献   

9.
Until the 20th century, forest policies across the globe focused primarily on effective forest utilization for timber production. Subsequent loss of forest land prompted many countries to review and amend such policies, in an attempt to incorporate the principles of conservation and sustainable forest management. One of the countries to implement such changes was India, which introduced new policies, acts and programmes to regulate forest conversion and degradation, beginning in the 1980s. These policies, acts, and programmes included the Forest Conservation Act of 1980, the National Forest Policy of 1988 and the Hon. Supreme Court Order of 1996. All of these regulations affected the timber supply from government forest areas, and created a huge gap in timber supply and demand. Currently, this deficit is met through imports and trees outside forests (TOFs). Timber production from government forest areas is abysmally low (3.35% of total demand) compared to potential timber production from TOFs, which fulfil 45% of the total timber demand in India. This implies that TOFs have immense potential in meeting the growing timber demand; however, they have not been fully utilized due to discrepancies in state level TOFs’ policies. The present paper provides a review of different forest policies, acts and guidelines in relation to timber production in India, and provides specific recommendations in order to maximize timber production in the context of increasing demand for timber products.  相似文献   

10.
Woodfuel balances are commonly used by energy planners in developing countries to determine the adequacy of woodfuel resources. Recently, critics have argued that wood balances are misleading in their simplicity, exaggerating both the severity of the woodfuel shortage and the need for planned interventions to solve that problem. This paper examines four different wood balances developed for Tanzania. While the four studies all indicate that areas with miombo woodlands are in the greatest wood surplus, the specific estimates for any given region may differ widely. Despite their shortcomings, energy planners need woodfuel balances to give an impression of the adequacy of woodfuel resources. However, if energy planning is to have any effect, these balances must represent the beginning, and not the end result, of the planning process. Planners must follow the wood-energy balance analysis with work utilizing local people to solve local problems.  相似文献   

11.
Land clearing and forest sector residues, notably the wastewood generated on large timber plantations, can provide a sizeable and hitherto neglected source of woodfuel. This article highlights experience in Malawi where wastewood from pine plantations is converted into charcoal that is sold to residential, industrial and agro-industrial users. Similar initiatives proposed in other countries of sub-Saharan Africa indicate that comprehensive utilization of wastewood resources could help to reduce regional and local imbalances.  相似文献   

12.
Comparison of data on world energy consumption for 1986, 1987 and 1988 indicates that the consumption of all forms of energy increased during the period, but the demand for oil increased at a lesser rate than that of other energy sources. Although the pattern varies between countries, the overall picture is one of increased use of natural gas, coal, nuclear and hydropower as an energy source. Part of the reason for the low growth in oil demand is the oil conservation measures put in place when oil was much more expensive, but may partly be due to the scepticism of many people about the future movement of oil prices. The likely continuation of a low growth market for oil has led some oil exporting countries to move downstream in an effort to secure a dependable market for their oil and oil products.  相似文献   

13.
This study aimed to analyze the global-scale substance flow of zinc associated with steel in order to discuss the sustainable use of zinc resources in the future. The relationship between the demand for steel and zinc was characterized in terms of zinc intensity for galvanized steel and the percentage of galvanized steel that accounts for the total steel demand. Zinc consumption for steel was divided into end uses according to the statistics on steel. Zinc demand in the future was forecasted with three scenarios for zinc intensity. Future steel demand was estimated using the stocks-drive-flows model, in which the demand is determined by the change in stock. The growth of in-use stock of galvanized steel in the future was estimated by considering economic growth on the basis of the transition of in-use stock of galvanized steel in the past. The cumulative zinc demand for galvanized steel up to the year 2050 was compared with the zinc reserves. It was found that the global average recovery rate of zinc was estimated at approximately 20% by the dynamic substance flow analysis for zinc. It is hoped that the recovery rate will increase. Even if zinc intensity is continuously reduced according to an experience curve based on technological development, a large portion of the current reserves will be consumed for galvanized steel. It was concluded that technological development in reducing zinc intensity will play a significant role in zinc resource conservation.  相似文献   

14.
Despite a decrease in indigenous forests and a growing demand for tree products in developing countries, tree planting activities are not considerably expanding in Tanzania. In this paper, we analyse factors that influence households’ tree planting behaviour, as well as the number of trees planted. Coast and Morogoro regions in the east of Tanzania were selected as the case, and data was gathered from 202 households in 11 villages in these regions where tree planting programmes have been or still are active. A Heckman model is used to analyse the factors that drive tree planting behaviour. Results indicate that households get wood energy from forest reserves (57%), in addition to their own planted trees (9.1%). Emperical findings show that the most important factors have significantly positive effects on households’ tree planting behaviour, as well as the extent to which it was implemented. These factors include households’ land sizes, households’ awareness of tree planting programmes, tree planting for wood energy, and the age of the head of the household. The right/freedom to harvest and transport tree products, households’ attitudes towards tree planting, and family size have significantly negative effects on households’ tree planting behaviour. This paper is perhaps the first comprehensive study to analyse the factors that influence households’ tree planting behaviour in Tanzania, and it uncovers results that are useful, even for other developing countries with similar conditions.  相似文献   

15.
During April 2007, forest land per capita in the United States dropped below 1 ha. This is the result of a rather static area of forest land in the United States for the past 100 years combined with population growth. The US now joins the ranks of most countries (77%) having forest land per capita below 1 ha. The combination of an increasing human population with stable or increasing per capita natural resource utilization may place even more demand on resources derived from forest land in the future. The forest land per capita should be expected to continue its downward trend unless substantive demographic, resource utilization, and land-use changes occur.  相似文献   

16.
文章阐述了发展生物燃料可实现缓解石油供需矛盾和减排温室气体的双赢目的,介绍了世界各主要消费大国发展,应用生物燃料的情况及生物燃料的发展趋势.  相似文献   

17.
This study explores electricity pricing as a demand-side management (DSM) strategy, looking to the developed country experience for insights into the types of approaches currently used, their effects, and the direction in which electricity pricing is headed. The discussion should be especially useful for electric utilities in developing countries that are exploring alternatives to capacity expansion to meet current and future electric power demand. For these electric utilities, demand-side options are especially important under today's conditions in which the capital cost of new generating capacity is increasing rapidly, international funds for expanding power sectors are not expected to be sufficient for meeting projected capacity needs and environmental concerns over fossil fuel emissions have raised new questions about constructing thermal power plants.  相似文献   

18.
Turkey's primary energy resources seem limited as indigenous energy production meets nearly 31 % of the total primary energy demand. But the growth of Turkey's industry gives rise to a substantial increase in energy demand. Final energy consumption grew from 52.6 Mtoe (million tons of oil equivalent) in the year 1990 to 78.4 Mtoe in the year 2002. Industrial demand accounts for about 41.6 % of the final energy demand in Turkey. Basic metal industries, non-metallic material products and chemical and petroleum products have the highest energy consumption in industrial sector. In this work, industrial energy consumption and energy consumption of different indsutrial subsectors in Turkey are investigated.  相似文献   

19.
Deforestation and decline in agricultural productivity are major concerns over large parts of sub-Saharan Africa. One of the principal causes for both these phenomena is the export of woodfuels from rural agroecosystems to urban markets. This process is noteworthy because of the size of the trade. Wood fuels (fuelwood, charcoal, and agricultural residues) constitute the most important source of energy in these countries, varying from 60% to 95% of total energy consumption. In terms of the environmental impact of the fuelwood trade, solutions typically considered are the introduction of improved cookstoves, fuelwood plantations, and fuel substitution by conventional fuels. This article examines the structure of the fuelwood problem, reviews the successes and failures of past experiences, and focuses on the potential for fuel substitution as an option to reduce the urban demand for fuelwood.  相似文献   

20.
Urban household energy use accounts for a large proportion of commercial fuel consumption in Nigeria. As population and urbanization increase, consumption is expected to rise rapidly in the future. It is therefore important to have information on the utilization pattern and factors driving consumption of urban household energy. Such information will be useful within the national energy planning framework for deriving strategies for a more rational energy utilization and increased reliability of energy supply to the urban household. In this paper, the major results from an urban household survey are presented. In the survey, data on various factors including energy consumption by income group, fuel preferences, sources and reliability of energy supply, and expenditure on energy are collected and analysed. Major conclusions are drawn on the possibilities for fuel supply/demand balance, and strategies for efficient energy utilization in the urban household .  相似文献   

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