Hydrogen: Its Future Role in the Nation's Energy Economy

In examining the potential role of hydrogen in the energy economy of the future, we take an optimistic view. All the technology required for implementation is feasible but a great deal of development and refinement is necessary. A pessimistic approach would obviously discourage further thinking about an important and perhaps the most reasonable alternative for the future. We have considered a limited number of alternative energy systems involving hydrogen and have shown that hydrogen could be a viable secondary source of energy derived from nuclear power; for the immediate future, hydrogen could be derived from coal. A hydrogen supply system could have greater flexibility and be competitive with a more conventional all-electric delivery system. Technological improvements could make hydrogen as an energy source an economic reality. The systems examined in this article show how hydrogen can serve as a general-purpose fuel for residential and automotive applications. Aside from being a source of heat and motive power, hydrogen could also supply the electrical needs of the household via fuel cells (19), turbines, or conventional "total energy systems." The total cost of energy to a residence supplied with hydrogen fuel depends on the ratio of the requirements for direct fuel use to the requirements for electrical use. A greater direct use of hydrogen as a fuel without conversion to electricity reduces the overall cost of energy supplied to the household because of the greater expense of electrical transmission and distribution. Hydrogen fuel is especially attractive for use in domestic residential applications where the bulk of the energy requirement is for thermal energy. Although a considerable amount of research is required before any hydrogen energy delivery system can be implemented, the necessary developments are within the capability of present-day technology and the system could be made attractive economically .Techniques for producing hydrogen from water by electrolysis, from coal, and directly from thermal energy could be found that are less expensive than those now available; inexpensive fuel cells could be developed, and high-temperature turbines could be used for the efficient conversion of hydrogen (and oxygen) to electricity. The use of hydrogen as an automotive fuel would be a key factor in the development of a hydrogen energy economy, and safe storage techniques for carrying sufficient quantities of hydrogen in automotive systems can certainly be developed. The use of hydrogen in automobiles would significantly reduce urban pollution because the dispersed fossil fuel emissions would be replaced by radioactive wastes generated at large central stations. The conversion of internal or external combustion engines for combustion of hydrogen fuel would probably have less economic impact on the automotive industry than the mass introduction of electric automobiles. However, this is a subject that requires more detailed study. All of the safety aspects of hydrogen utilization will have to be examined, especially the problems of safety in the domestic use and the long distance transport of hydrogen in pipelines at high pressures. It is our opinion that the various energy planning agencies should now begin to outline the mode of implementing hydrogen energy delivery systems in the energy economy. The initial transition to hydrogen energy derived from available fossil fuels such as coal should be considered together with the long range view of all the hydrogen being derived eventually from nuclear energy. By the year 1985 when petroleum imports may be in excess of the domestic supply, these plans could set the stage for the transition period from fossil to a predominantly nuclear energy economy able to supply abundant synthetic fuels such as hydrogen. Synthetic fuels will obviously be more expensive than fuels now derived from petroleum; however, there may be no other viable choice. Thus, it is essential that the analysis and technological feasibility of a hydrogen energy system be considered now. It is of vital importance to the nation to develop some general-purpose fuel that can be Produced from a variety of domestic energy sources and reduce our dependence on imported oil.     

Biomechanical energy harvesting: generating electricity during walking with minimal user effort

We have developed a biomechanical energy harvester that generates electricity during human walking with little extra effort. Unlike conventional human-powered generators that use positive muscle work, our technology assists muscles in performing negative work, analogous to regenerative braking in hybrid cars, where energy normally dissipated during braking drives a generator instead. The energy harvester mounts at the knee and selectively engages power generation at the end of the swing phase, thus assisting deceleration of the joint. Test subjects walking with one device on each leg produced an average of 5 watts of electricity, which is about 10 times that of shoe-mounted devices. The cost of harvesting-the additional metabolic power required to produce 1 watt of electricity-is less than one-eighth of that for conventional human power generation. Producing substantial electricity with little extra effort makes this method well-suited for charging powered prosthetic limbs and other portable medical devices.     

Photovoltaic materials

Solid-state photovoltaic cells are feasible devices for converting solar energy directly to electricity. Recent cost reductions have spurred an incipient industry, but further advances in materials science and technology are needed before photovoltaic cells can compete with other sources for the supply of large amounts of energy. In this article energy loss mechanisms in solid-state photovoltaic cells are examined and related to materials properties. Various systems under development are reviewed which illustrate some key concepts, opportunities, and problems of this most promising emerging technology. Areas where contributions from innovative materials research would have a significant effect are also indicated.     

峰谷分时分季上网电价计算模式及应用

在研究制定上网电价的基本原则和方法的基础上，提出了水电厂峰谷分时上网电价和丰枯分季上网电价的计算模式。这种模式，既适用于按财务决算资料来确定分季峰谷上网电价，也适用于按现行电价水平来制定分季峰谷上网电价     

Energy analysis of the solar power satellite

The energy requirements to build and operate the proposed Solar Power Satellite are evaluated and compared with the energy it produces. Because the technology is so speculative, uncertainty is explicitly accounted for. For a proposed 10-gigawatt satellite system, the energy ratio, defined as the electrical energy produced divided by the primary nonrenewable energy required over the lifetime of the system, is of order 2, where a ratio of 1 indicates the energy breakeven point. This is significantly below the energy ratio of today's electricity technologies such as light-water nuclear or coal-fired electric plants.     

A global and long-range picture of energy developments

Most studies of energy supply and demand ignore either global inter-dependence or the long time spans necessary to adjust to new energy sources. The International Institute for Applied Systems Analysis has therefore studied on a global scale, for seven major world regions, the balance between energy supply and demand for the next 50 years. Reported here are the results for two benchmark scenarios. In the "low" scenario world energy consumption increases from today's 8.2 terawatt-year per year to 22 terawatt-year per year in 2030; in the "high" scenario, consumption increases to 35 terawatt-year per year. The study showed that time will be the limiting constraint in adapting the energy supply infrastructure to changing resource availability; resources will be available until the second half of the next century, but a strong shift will be required to low-grade fossil fuels such as shale oil and tar sands. Each scenario studied indicated increased environmental problems associated with increased use of fossil fuels, and potential geopolitical problems associated with the world distribution of resources.     

论农村低碳经济发展的影响因素与政府规制

分析了导致我国农村低碳经济发展困难的主要因素,包括：农村能源结构不合理、基础设施和技术相对落后、法律法规和政策体系不健全、资金筹集机制发育缓慢、农民低碳意识和能力有限等。针对这些不利因素,从政府规制的角度提出了针对我国农村低碳经济发展实际的具有可行性的策略。     

Generating electricity while walking with loads

We have developed the suspended-load backpack, which converts mechanical energy from the vertical movement of carried loads (weighing 20 to 38 kilograms) to electricity during normal walking [generating up to 7.4 watts, or a 300-fold increase over previous shoe devices (20 milliwatts)]. Unexpectedly, little extra metabolic energy (as compared to that expended carrying a rigid backpack) is required during electricity generation. This is probably due to a compensatory change in gait or loading regime, which reduces the metabolic power required for walking. This electricity generation can help give field scientists, explorers, and disaster-relief workers freedom from the heavy weight of replacement batteries and thereby extend their ability to operate in remote areas.     

Energy and water

The geographic and temporal variability of freshwater supply in the United States constrains the choice and level of use of future energy sources. Ecological criteria for acceptable freshwater consumption, together with hydrological data on stream flow, provide a framework for estimating these constraints. The water consumption requirements for a variety of energy options are presented, and comparative judgments drawn. Attention is focused on problems resulting from synthetic, gaseous, and liquid fuel production. Scenarios describing possible future levels of coal and electricity use are analyzed. They point to the importance of water supply constraints in both the eastern and western United States.     

Simulation modeling of engineering networks

The problem of optimizing a water supply and distribution system combining simulation modeling and genetic algorithm methods is examined. Unlike traditional methods, the components of operating costs are obtained by summing hourly expenditures for electricity during the entire simulation period. Thus, there is no need for a poorly substantiated coefficient of cyclic variation of electricity consumption. Variants with and without control of pumping units are compared.     

信息化技术进步、制度变迁与洞庭湖生态经济区农业发展模式演进

农业经济增长离不开农业信息化技术进步的推动,也需要借力制度变迁。农业经济增长是动态发展过程,随着农业信息化技术进步与诱致性制度变迁持续向更高水平和更深层次演进。现阶段,洞庭湖生态经济区农业经济处于较为快速的发展状态。研究发现农业信息化技术进步与制度变迁存在偏差,需要基于农业信息化技术进步和制度变迁的耦合视角探索推进农业发展模式演进的路径。研究表明,洞庭湖生态经济区农业信息化技术进步推动传统农业向知识型农业转型、农业生产结构调整、增强农产品竞争力、改变农户生产生活方式,洞庭湖生态经济区推动了农业贷款体制变迁、农村财政体制供给的变迁,但依然存在认识农业信息化不充分、农村信息技术设施建设滞后、农业信息化技术与传统农业深度融合存在瓶颈等问题,需要继续加大农村信息化基础设施建设、推进大数据建设、强化区域信息协同治理、完善智慧农业政策体系。     

Energy and the u.s. Economy: a biophysical perspective

A series of hypotheses is presented about the relation of national energy use to national economic activity (both time series and cross-sectional) which offer a different perspective from standard economics for the assessment of historical and current economic events. The analysis incorporates nearly 100 years of time series data and 3 years of cross-sectional data on 87 sectors of the United States economy. Gross national product, labor productivity, and price levels are all correlated closely with various aspects of energy use, and these correlations are improved when corrections are made for energy quality. A large portion of the apparent increase in U.S. energy efficiency has been due to our ability to expand the relative use of high-quality fuels such as petroleum and electricity, and also to relative shifts in fuel use between sectors of the economy. The concept of energy return on investment is introduced as a major driving force in our economy, and data are provided which show a marked decline in energy return on investment for all our principal fuels in recent decades. Future economic growth will depend largely on the net energy yield of alternative fuel sources, and some standard economic models may need to be modified to account for the biophysical constraints on human economic activity.     

中国交通基础设施与农村经济增长的实证研究

在“两区域、两要素和两部门”模型的基础上,运用规范分析方法讨论了公共服务的市场接近效应及其对要素空间聚集（扩散）的影响,研究表明公共服务供给的变化会通过市场接近效应影响要素空间集聚（扩散）,改变区域空间经济结构.     

German energy technology prospects

After more than 25 years of development of nuclear power and almost 10 years of research and development in numerous areas of nonnuclear energy, there is now a good basis for judging the future prospects of energy technologies in the Federal Republic of Germany. The development of nuclear power has provided an important and economically advantageous new source of energy. Further efforts are needed to establish the nuclear fuel cycle in all stages and to exploit the potential of advanced reactors. In all other areas of energy technology, including energy conservation, new energy sources, and coal, economics has turned out to be the key problem, even at today's energy prices. Opportunities to overcome these economic problems through additional R & D are limited. There is some potential for special applications, and there are many technologies that could contribute to the energy supply of developing countries. In general, however, progress in energy conservation and the use of renewable energy sources will depend on the degree to which energy policy measures can improve their economic basis. For some technologies, such as solar thermal power stations and coal liquefaction, large-scale economic deployment cannot be foreseen today. Instead of establishing costly demonstration projects, emphasis will be put on improving key components of these technologies with the aim of having the most advanced technology available when the economic parameters are more favorable.     

风光互补发电系统在转地饲养蜂场中的应用研究

在蜂群转地饲养中,由于场地条件的限制,蜂农的生产、生活难以获取现有交流市电的支持,经过实地蜂场调研,目前蜂农多数使用光伏组件收集太阳能作为能提供源。蜂农在户外难免遇到连续阴雨或者多云天气,无法为蓄电池充电,现有装置就无法满足蜂农的要求。针对这种现状,以风光互补发电系统作为切入点,针对转地饲养蜂农供电问题进行研究,将风力发电与太阳能发电结合起来,弥补连续阴雨天供电不可靠的缺陷,同时能够保证用户均衡充足的用电需求,为蜂农野外养蜂作业提供新的技术理论参考。     

外国农业公司进入中国市场的优势浅析

海外农业公司资金充足,可以进行大规模的基础设施建设和新设备引进,其产品技术含量高,更能够满足市场的需求。国外农业公司由于有资金优势、技术优势、市场运作优势,能够满足中国对农业产品不断增长的需求,在未来的市场竞争中将取得良好的业绩和丰厚的经济回报,针对这一发展趋势进行了较为深入地分析。     

LNG冷能用于冷库的系统设计及分析

为了将LNG（Liquefied Natural Gas）冷能作为冷库的冷源,以节省投资、减少电耗、降低冷库的生产成本,结合福建LNG总体项目,确定了LNG冷能用于冷库的系统流程与运行模式,并以供气规模为4000万m3／年的气化站为例,进行了系统节能分析和计算．结果表明：在冷库系统冷量回收率为33％的情况下,该气化站可回收冷量的年冷量收益为611．3万元,投资回收期小于1年．因此,利用LNG冷能作为冷库的冷源是一种可行的方式,具有显著的节能效果和经济效益．     

广西特色经济农产品供应链及其品牌建设研究——以桂林地区为例

首先简单介绍特色经济农产品地域性强和市场竞争力强的特点,说明广西特色经济农产品的现状。然后以桂林为例,通过对桂林地区特色经济农产品供应链及品牌建设现状的分析,指出桂林地区农产品供应链及品牌建设中存在的问题：农产品供应链中存在农业生产基础设施薄弱、产品的精深加工能力不足、储运方式现代化水平低、固定营销渠道短缺的问题;品牌建设中存精品名牌少、差异化产品少的问题。最后针对这些问题从树立农产品供应链管理理念和加强农产品品牌保护意识两方面提出对策,并建议把这些对策推广到广西全自治区,旨在为广西特色经济农业发展探寻出路。     

我国农村能源发展现状及开发利用模式

针对我国农村能源消费结构不合理,能源消费层次低等农村能源开发利用问题,采用国家统计局对我国农村东部、中部、西部、东北4个地区的划分方式,对我国农村能源发展现状及开发利用模式进行研究。结果表明:1)近年来我国农村能源产业总体表现出良好态势;2)东部、中部、西部、东北等不同地理位置农村能源开发利用模式各不相同,东部地区能源使用多元化,中部、西部地区完善农村电网工程,加大新能源使用力度,东北地区大力开发太阳能解决冬季采暖问题;3)我国农村能源体系存在推广落后、发展基础设施落后、政策落后等问题。由于不同地区生活习性、经济发展水平、历史发展原因不尽相同,资源禀赋、农村能源供需结构存在较大差异,因地制宜开发利用农村能源,完善农村能源基础设施网络,把地方资源优势转变为经济优势、产业优势,是解决农村能源建设问题的主要动力。     

河南省农业生物质资源能源利用潜力分析

为了挖掘农业生物质资源的能源利用潜力,根据河南省农业统计数据(农作物产量和畜禽养殖量),经计算可知,河南省每年可用农业生物质资源量折合标准煤约3 045万t;采用不同的生物质供热和发电技术,每年具有1.74×107 MJ供热潜力和542亿kW.h发电潜力,可节省2 455万t标准煤。河南省农业生物质资源具有巨大的能源利用潜力。