天然气热电冷总能系统应用模式的探讨

我国的天然气储量相对有限，并且远离需求中心；与国际水平相比，中国的天然气价格较高。为了使天然气得到合理有效的利用，应该提高能源的利用率。针对这种情况，提出了天然气热电冷总能系统的应用模式，并对不同模式所用的几种主要动力设备进行了比较，以燃气内燃机加余热型直燃机和燃气机热泵系统为例对联结方式进行了论述。最后对系统的特点以及在国内的发展和应用情况进行了介绍，并指出了在我国的发展前景。     

Standalone hybrid system energy management optimization for remote village considering methane production from livestock manure

Recently, many efforts have been done to overcome increasing fuel consumption. One of the vital solutions is utilization of standalone renewable energy resources hybrid systems. This paper attempts to develop a cost-effective methodology to ascertain optimal design and energy management for a remote village. Different energy resources such as wind and solar, fuel cell, and energy storage systems are employed to satisfy total demands including agriculture, residential, school, and health center. Different hydrogen production methods are proposed to verify the efficiency of the developed methodology. In the proposed village, different waste types such as rice husk, maize straw, livestock, and residential wastes are used to generate the required hydrogen for fuel cells to generate electricity. The main objective of the proposed methodology is minimizing the total cost of the village including total costs of each Distributed Generation (DG), cost of natural gas consumption, penalty for interruption the demands, and cost of CO₂ emission. A Particle Swarm Optimization (PSO) algorithm is employed to solve the optimization problem by minimizing the total system costs while the customers required Loss of Power Supply Probability (LPSP) is satisfied. The suggested hybrid system not only increases the renewable energy penetration but also decreases the natural gas consumption. The results achieved in the course of the present study depict that utilization of energy produced from different types of wastes plays a significant role in conserving fossil fuels and overcoming the fossil fuels depletion. It is concluded from the results that there is about a 17.46% reduction in natural gas consumption when all available waste is utilized. In addition, considering 100% availability for the animal manure reduces the natural gas consumption by reformer from 2.373 to 1.605 million liters which means reduction of the natural gas consumption is 32.35%. The results conclude that H₂ produced by livestock waste is dominating among available wastes. However, there is about 18% reduction in the Cost of Energy (COE), when 100% availability is considered for this type of waste.     

The demand for energy for irrigation in the USA

There seems to be some question concerning the relationship between irrigation and the price of energy. Did changes in the price of energy actually impact irrigation in the USA? Additionally, the substitution between alternative types of energy seems to be a possibility for irrigation. Whether in fact it occurred is another matter. In this study, an appropriate model is developed and estimated to address the issues. The specific energy types considered include motor gasoline, diesel fuel, liquefied petroleum gas, natural gas and electrical energy. The results for 1978 and for 1980 clearly indicate that energy use for irrigation is responsive to the price of energy. Additionally, some substitution between energy types took place during this period. Finally, when the question of the stability of the demand for the various energy types is addressed, the suggestion is that the demand for the energy types considered was stable for the 1978 and 1980 periods.     

Natural gas demand in Turkey

On average, energy demand of Turkey is mounting by 8% annually, one of the highest rates in the world. Among primary energy sources, natural gas is the fastest growing one in Turkey. Gas consumption started at 0.5 bcm (billion cubic meters) in 1987 and reached approximately 35 bcm in 2007. Turkish natural gas usage is projected to further increase remarkably in coming years. The present paper focuses the characteristics of this demand and estimates short and long-run price and income elasticities of sectoral natural gas demand in Turkey. The future growth in this demand is also forecasted using an ARIMA modelling and the results are compared with official projections. The paper reveals that natural gas demand elasticities are quite low, meaning that consumers do not respond possible abusive price increases by decreasing their demand or substituting natural gas with other energy sources. Since consumers are prone to monopoly abuse by incumbent, there is a need for market regulation in Turkish natural gas market. Based on forecasts obtained, it is clear that the current official projections do not over/under-estimate natural gas demand although past official projections highly overestimated it.     

计及多能需求的综合能源服务商优化运行策略研究

随着分布式发电技术的不断成熟及发展,未来综合能源服务将是整合不同类型分布式发电并满足用户不同用能需求的有效途径.提出了一种含有多种分布式发电资源同时考虑多用能需求的综合能源服务商优化运行策略模型.首先建立了含有风电、光伏、燃气轮机、电储能、电热泵、辅助锅炉等分布式资源及电、热用能需求的园区综合能源系统优化调度模型;其次...     

The economic effect of efficiency programs on energy consumers and producers

An increase in the efficiency of natural gas fired residential appliances allows users to realize the same level of service, heating water for example, while using less natural gas. In addition to this technological benefit to the residential sector, the reduced demand for natural gas depresses the price of natural gas, resulting in pecuniary gains to other energy consumers and pecuniary losses to energy producers. The question we address in this study is whether purely pecuniary effects, those that follow from the price changes elicited by lower usage of natural gas, should enter the debate concerning the implementation of energy efficiency programs. To that end, we explore the price and social welfare impacts of natural gas energy efficiency standards by evaluating the impacts of a specific efficiency standard using the National Energy Modeling System. Our analysis indicates that purely pecuniary losses to producers are largely offset by pecuniary benefits to consumers. Our analysis also provides useful insight into the sources of these benefits and losses. Although our results are based on a specific model and efficiency standard, we believe that the results generalize to other efficiency programs and would be reproduced using other energy models.     

Systematic approach to natural gas usage for domestic heating in urban areas

Natural gas can be used for satisfying population needs for heating, either directly by bringing the gas to the dwellings through the gas distribution system and combusting it in the domestic boiler (gas distribution system—G) or indirectly by combusting the natural gas in the heating plant and distributing the heat energy to the dwellings through the district-heating (DH) system. The selection of a certain type of heating system is made according to the disposition of buildings in the area, their number, size, insulation quality, etc. Based on these characteristics, calculations of investments and exploitation costs have been made for both heating systems and a comparison has been made for all of the 96 presented cases. Almost each type of real settlement can be represented by one of the types of the conditional urban area that are introduced in the paper. The main goal of this paper is to establish a general model to achieve coordinated development of centralized energy supply systems fueled by natural gas, based on defined and accepted criteria. A structure analysis of centralized systems for energy supply has been done with accent on their pipelines.     

Federal incentives for energy development

This paper identifies and quantifies the incentives utilized by the Federal government to encourage the development of U.S. energy resources over the past half century. The incentives granted to the six major conventional sources of energy—nuclear energy, hydropower, coal, oil, natural gas, electricity—are categorized according to eight general types: creation (prohibition) of organizations, taxation, fees, disbursements, requirements, traditional government services, non-traditional government services, and market activity. It is found that through the fiscal year 1977 the Federal government has expended $211 billion for incentives to encourage energy resource development. These incentives were distributed in the following manner: commercial nuclear power, $18 billion; hydropower, $15 billion; coal, $10 billion; oil, $101 billion; natural gas, $16 billion; electricity transmission/distribution, $70 billion. The implications of these findings are discussed briefly.     

Does renewable energy substitute LNG international trade in the energy transition?

Renewable energy is a vital tool for the energy transition and sustainable development goals. The global economy, however, remains heavily reliant on fossil fuels despite efforts to reduce global greenhouse gas emissions. Demand for natural gas is rising as a bridge for moving towards a low-carbon economy, but whether natural gas and renewable energy represent substitutes in the global energy mix remains underexplored. We tackle this concern by examining the impact of renewable policies on international trade in liquified natural gas (LNG) among 1359 trading partners during the period 1988–2017. We measure renewable energy policies based on the ratio of renewable energy to total energy usage in importing trading partners, which also corresponds to a proxy for energy transition policies. The analysis is conducted using a global panel dataset in a trade gravity framework by applying various econometric methods and model specifications to measure LNG trade as a dependent variable. The results show that the energy transition, measured by the share of renewable energy, has a negative impact on LNG trade. This suggests that investing in cleaner energy technologies can reduce LNG trade globally, as a channel towards reducing natural gas demand. The results are consistent with the narrative where natural gas and renewable energy represent partial substitutes at the global level. However, subgroup analysis suggests that less-developed economies and the shale revolution period seem to impede progress towards the energy transition.     

中国中长期碳减排战略目标初探(Ⅳ)——天然气能源在中国的应用前景和碳减排分析

中国目前天然气在能源消费结构中的比例不到4%。与欧美发达国家相比,中国在商业和居住方面的年人均天然气消费量要低30多倍;按照EIA的中长期预测,中国天然气仅占家庭用能的21%～28%、商业用能的14%～20%,与发达国家大约相差1倍。中国用于发电的天然气使用量不到2%,由于风电比例的提高,非常有必要争取2050年将天然气调峰发电的比率提高到5%以上。如果2030年中国天然气产量达到3000×108m3并加大从国外的进口量,使消费量达到5000×108m3,天然气在能源消费结构中的比率有可能提高到14%。制约中国天然气消费量提高的因素包括国内天然气产量、国外进口量、基础设施建设和天然气价格等。提出2050年中国实现天然气消费量达到6000×108m3和8000×108m3的两个情景,其基础是确保常规天然气产量为2500×108m3,页岩气产量达到1000×108~1500×108m3,煤层气和煤制替代天然气产量达到1000×108~1500×108m3,进口量为1500×108~2500×108m3,这是一个非常艰巨但却有可能实现的目标。如果2050年中国天然气消费量达到8000×108m3的高消费量情景,按照发改委能源研究所设定的节能情景的能源消费总量测算,天然气在一次能源消费结构中的比例可上升到14%;按低碳情景测算,天然气的比例可上升到18%;按强化低碳情景测算,天然气的比例可上升到20%,达到目前世界的平均水平。两个天然气消费情景的二氧化碳排放量分别为7.4×108t和9.6×108t。从各方面而言,增加天然气消费量都是正效应而非负效应。     

Assessment and exploitation of energy-related externalities in the industrial sector

The scope of this paper is to comparatively evaluate the effectiveness of alternative policy measures in reducing impacts from atmospheric pollution generated from industrial energy use. The evaluation procedure relies on the assessment of energy-related externalities by exploiting the methodology developed in the framework of the ExternE project. The analysis focuses on 2 industrial units located in the Greater Athens area and examines three types of abatement measures that can be used independently of the extent energy saving or end-of-pipe emission reduction measures are used: substitution of fuel oil with natural gas, relocation of the units several hundreds of kilometers far from Athens and increase of stack height in the same site. It results that the use of natural gas is by far the most effective among these measures, leading to a reduction of more than 90% of both local and regional damages. The relative effectiveness of the examined measures does not change if the significant uncertainties associated with the accounting procedure are taken into account, while inclusion of the external cost due to greenhouse gases emissions is further accentuating the advantages of natural gas. Moreover, it is shown that the quantifiable energy-related external costs of a single industrial product, may be very low compared to the corresponding private costs, but they sum up to significantly high damages to society if we take into account the total energy consumption in the industrial sector.     

Large-scale hydrogen energy storage in salt caverns

Large-scale energy storage methods can be used to meet energy demand fluctuations and to integrate electricity generation from intermittent renewable wind and solar energy farms into power grids. Pumped hydropower energy storage method is significantly used for grid electricity storage requirements. Alternatives are underground storage of compressed air and hydrogen gas in suitable geological formations. Underground storage of natural gas is widely used to meet both base and peak load demands of gas grids. Salt caverns for natural gas storage can also be suitable for underground compressed hydrogen gas energy storage. In this paper, large quantities underground gas storage methods and design aspects of salt caverns are investigated. A pre-evaluation is made for a salt cavern gas storage field in Turkey. It is concluded that a system of solar-hydrogen and natural gas can be utilised to meet future large-scale energy storage requirements.     

China’s natural gas reform: why and how

Natural gas is playing an extremely significant role in implementing green and low-carbon economy in China, while its share in energy mix only accounted for 6.4% of China’s total energy consumption in 2016. The Chinese government began to make a series of policies and measures to catalyze natural gas production and consumption for dealing with severe air pollution and optimizing energy structure. Some key issues such as highly regulated natural gas pricing system, the monopoly of natural gas pipelines, and the dominance of state-owned oil companies are substantially existing to be addressed in the forthcoming natural gas reforms. The dilemma of reforms is analyzed in this article and the related reform solutions are to be explored in the deregulation of Chinese natural gas pricing mechanism, separation of state-owned companies’ pipeline, and nondiscriminatory third-party access. The results show that Chinese natural gas reform is destined to be a long-lasting war.     

加速发展天然气产业是我国能源结构调整的核心任务之一

加速发展天然气产业应是我国能源结构调整的核心任务之一。由非常规天然气带动的天然气"革命"为世界天然气产业发展创造了有利的资源条件,全球天然气过剩,价格下降。目前我国天然气在一次能源结构中所占的比例仍然过低,只达到世界水平的1/4左右,而提升天然气的消费比例与提高综合能效具有正相关关系。综合考虑,"十二五"末我国天然气在一次能源消费中的比例应达到12%～15%,甚至更多一些。21世纪以来我国常规天然气储产量增长迅速,新增探明天然气储量已连续7年保持在5000×108m3以上。预计2020年我国天然气年产量将达到2000×108m3,2030年前后可达到2500×108～3000×108m3,加上从国外进口的天然气(包括沿海进口的LNG)和煤制气的发展,天然气消费总量将达4500×108m3,占国内一次能源消费比重可望有一个大幅度的提升。"十二五"期间我国煤层气开采可望首先获得突破性进展,而页岩气正处于勘探开发起步的关键时期,国家在加强领导的同时要加大扶持力度。天然气储运工程对于天然气产业和市场的发展非常重要,"十二五"期间成立中国天然气管道总公司的条件已经成熟。     

Modeling and forecasting natural gas demand in Bangladesh

Natural gas is the major indigenous source of energy in Bangladesh and accounts for almost one-half of all primary energy used in the country. Per capita and total energy use in Bangladesh is still very small, and it is important to understand how energy, and natural gas demand will evolve in the future. We develop a dynamic econometric model to understand the natural gas demand in Bangladesh, both in the national level, and also for a few sub-sectors. Our demand model shows large long run income elasticity – around 1.5 – for aggregate demand for natural gas. Forecasts into the future also show a larger demand in the future than predicted by various national and multilateral organizations. Even then, it is possible that our forecasts could still be at the lower end of the future energy demand. Price response was statistically not different from zero, indicating that prices are possibly too low and that there is a large suppressed demand for natural gas in the country.     

Clean energy adoption and maternal health: Evidence from China

Maternal mortality in China decreased 59% during 2000–2014, while clean energy consumption nearly doubled. This paper examines how the widespread adoption of natural gas as a source of clean energy improves the health of pregnant women, an environment-sensitive group often ignored in previous pollution studies. Using variation across provinces and over time in the density of natural gas infrastructure in China, we identify a significant and negative clean energy adoption – maternal mortality relationship in China. Specifically, we find that a one-unit increase in natural gas density – measured by the length of natural gas pipelines per 10,000 persons – would cause the maternal mortality rate to decrease by 4%, which would translate into an annual gain of approximately 648 pregnant women’s lives. We also present several additional specification checks and find that the results are insensitive to these considerations. This finding suggests that natural gas adoption has substantial health externalities and should be an important part of policy discussions surrounding clean energy production. To our knowledge, this is the first study to draw a causal link between clean energy use and maternal mortality.     

Microbial hydrogen production from replenishable resources

It is estimated that more than 90% of the world's present energy needs are provided by fossil fuels such as oil, natural gas and coal, which until a few years ago were regarded as an endless source of cheap energy. However, these fossil fuels represent a non-replenishable natural resource. The cost of oil and natural gas is escalating rapidly, while the world energy demand continues to increase due to population growth and technological development. Therefore, there is a need to develop new sources of energy based on replenishable cheap raw materials. One such approach of potential importance is the use of carbohydrates which are biochemically converted to hydrogen gas by a wide variety of microorganisms. This paper reviews the conditions of microbial growth and metabolism which result in the production of hydrogen gas. It is concluded that microbial hydrogen production represents a potential new energy source and a lot of basic research is needed to establish the economic feasibility of hydrogen production from various microbial systems.     

“十二五”期间我国天然气消费格局主要特征及发展方向探讨

我国天然气消费水平较低,虽然自本世纪以来有了较大提高,但与一些发达国家相比仍有很大差距和发展空间。我国能源供应长期以煤炭为主的局面在"十一五"变化不大,"十二五"期间提高天然气占一次能源的比重是我国节能减排最重要、最可行的措施之一。广泛应用天然气除了可提高热效率以外,还可以减少废气排放总量。当前,我国天然气的主要用途是替代城市居民生活用煤,然而单一采用民用燃气方案必定存在供气量波动较大的缺点,日本和韩国在促进天然气消费的政策措施方面有不少成熟经验值得我们借鉴。当前城市燃气已成为我国天然气消费的主力,同时应高度重视建筑节能,DES/CCHP就是一种具有代表意义的建筑节能技术,应有计划、有步骤地对其进行试点,做到多实践、少争论。同时应大力发展天然气汽车,并努力解决其经济性和加气难的问题。我国"十二五"期间天然气利用存在两个主要问题,一是天然气价格,二是天然气储气与调峰。天然气利用应遵循因地制宜和逐步升级开发的原则,进一步深化、优化天然气利用应是我国发展天然气产业的一个重要战略措施。     

Approach and potential of replacing oil and natural gas with coal in China

China’s fossil energy is characterized by an abundance of coal and a relative lack of oil and natural gas. Developing a strategy in which coal can replace oil and natural gas is, therefore, a necessary and practical approach to easing the excessive external dependence on oil and natural gas. Based on the perspective of energy security, this paper proposes a technical framework for defining the substitution of oil and natural gas with coal in China. In this framework, three substitution classifications and 11 industrialized technical routes are reviewed. Then, three scenarios (namely, the cautious scenario, baseline scenario, and positive scenario) are developed to estimate the potential of this strategy for 2020 and 2030. The results indicate that oil and natural gas replaced by coal will reach 67 to 81 Mt and 8.7 to 14.3 Gm³ in 2020 and reach 93 to 138 Mt and 32.3 to 47.3 Gm³ in 2030, respectively. By implementing this strategy, China’s external dependence on oil, natural gas, and primary energy is expected to be curbed at approximately 70%, 40%, and 20% by 2030, respectively. This paper also demonstrates how coal, as a substitute for oil and natural gas, can contribute to carbon and pollution reduction and economic cost savings. It suggests a new direction for the development of the global coal industry and provides a crucial reference for energy transformation in China and other countries with similar energy situations.