论夏热冬冷地区地板采暖的可行性

随着国民经济的发展及生活水准的提高，作为一种高效节能、舒适性佳的住宅采暖方式——地板采暖受到国内越来越多的关注。住宅产业的发展及国家节能法规的实施则为此行业的发展提供了机遇和挑战。2001年夏热冬冷地区推出了节能规范，以积极推广健康、舒适、节能的住宅温热环境技术。文中对夏热冬冷地区的经济发展状况及地理气候环境特点等作了调查分析。并结合国家对该地区的节能规范考察了地板采暖的发展可行性，并预测了应用前景。     

Renewable energy technologies for irrigation water pumping in India: projected levels of dissemination, energy delivery and investment requirements using available diffusion models

Using the past diffusion trends of four renewable energy technologies for irrigation water pumping in India (SPV pumps, windmill pumps and biogas/producer gas driven dual fuel engine pumps), results of an attempt to project their future dissemination levels, have been presented in this study. The likely contribution of the renewable energy options considered in the study to the projected energy demand for irrigation water pumping in India has been estimated. Estimates of the associated investment requirements taking into account the learning effect have also been presented.     

Home energy use in nine OECD countries, 1960–1980

Government institutions and individuals have responded to fluctuations in energy supply and price with the implementation of policies and the initiation of conservation. While these activities have resulted in noticeable conservation of energy, primarily through behavioural actions, further savings could be achieved through the exchange of information regarding promising policies and technologies. Toward this end, data on residential sector energy use for nine OECD countries (Canada, Denmark, France, West Germany, Italy, Japan, Sweden, the UK and the USA) have been collected over the period 1960–1980 and have been analysed using both indicators of energy-use intensity and econometric methods.     

Wind energy in Sudan : Water pumping in rural areas

New and renewable sources of energy can make an increasing contribution to the energy supply mix of developing countries in view of favourable renewable energy resource endowments, limitations and uncertainties of fossil fuel supplies, adverse balance of payments, and the increasing pressure on the environment from conventional energy generation. Among the renewable energy technologies, the generation of mechanical and electric power by wind machines has emerged as an economically viable and cost effective option. Therefore the Sudanese government has begun to pay more attention to the use of wind energy in rural areas in particular as a cost-effective solution to assist in water pumping and irrigation.     

Net energy analyses of four technologies to provide residential space heat

After having calculated energy ratios for four methods of providing residential space heat, passive solar heating systems were found to return approx. 20–25 units of energy for each unit of energy invested. The other technologies (active solar, electrically powered heat pump, and a synthetic gas fueled hot air furnace) had energy ratios of 1.7–5.6. The low energy ratios for active solar energy systems (both air and water) and conventional space heating methods are due to the fact that these technologies employ energy-intensive materials in the equipment used to produce and distribute residential heat. Passive solar energy systems use few components beyond the relatively low energy intensity materials used for standard construction techniques and generally use no energy to distribute the captured heat. Based on these estimates and projected life cycle costs for these energy producing techniques, as well as on some standard energy-conserving techniques, it is apparent that the United States would produce more energy per dollar and energy input with conservation and passive solar strategies than with residential heating techniques depending on coal as a primary fuel.     

How to support growth with less energy

Economic growth with less use of primary energy and lower carbon emissions can be achieved through existing and new technical solutions and by behavioural change. These solutions secure growth with lower carbon emissions and reduce our dependence on oil and gas, thereby improving security of energy supply. The implication of the Energy White Paper goal of reducing CO₂ emissions by 60% by 2050 is a six-fold reduction in the carbon intensity of the UK economy, and further reductions will be needed. Efficient and renewable supply, distribution and end-use technologies have multiplicative effects, but constraining demand growth is crucial to the rate and extent of reducing emissions. Goals include reductions in the energy intensity of transport and buildings and in the energy intensity of major building materials with the development of technologies and demand management. There will also need to be infrastructural developments that encourage low-carbon technologies and increase energy diversity and security of supply, better low-carbon planning and improved co-ordination of planning, building control and other policy tools, better monitoring and feedback on the real performance of energy-efficient technologies, and improved capabilities to model whole energy systems, including demand and supply as well as social and economic issues.     

A decision-making approach for energy efficiency improvement in municipal water pumps during water scarcity scenario

Cities in Sub-Saharan Africa suffer from widespread disparities in water supply due to depletion in groundwater and global-warming-induced changes in weather patterns. The offset of water head from the design considerations of water pumping systems has increased energy requirements leading to worsening of the situation with respect to availability of energy and water. Consequently, highly capitalized water supply schemes, which have been designed to meet the demand, are underutilized leading to operational inefficiencies. Robust empirical equations can help detect inefficiencies in water pumping systems, and this paper discusses the equations which were developed by analysing data obtained from various water supply utilities facing water scarcity. These equations provide cost-benefit analysis for decision making in water utilities and can bring about energy efficiency in municipal pumping operations.     

Evaluation of cooking energy cost,efficiency, impact on air pollution and policy in Nigeria

This study evaluated the cooking energy costs and efficiencies, the air pollution impacts of cooking energy consumption and the impact of the energy policy in the cooking energy sector in Nigeria. Water boiling and cooking experiments using the common cooking energy sources (fuel wood, kerosene, liquefied petroleum gas (LPG) and electricity) and common food items (water, yam and beans) were carried out. Energy surveys were carried out to determine the cooking energy use patterns in the urban and rural areas. It was found that fuel wood is the least expensive cooking energy source and LPG is the most expensive. Energy use efficiencies for boiling water were estimated at 25%, 46%, 73%, 79%, 66% and 90% for fuel wood, kerosene, gas, electric immersion coil, electric heating coil and electric hot plate, respectively. Energy intensity was found to be a comparative measure of energy efficiency. The impacts of air pollution from household cooking suggested a possibility of significant air pollutants contribution to the ambient environment using any of the energy carriers considered except electricity. The cooking energy use patterns showed that fuel wood is the predominant energy source for cooking in the rural areas while kerosene is the predominant energy source in the urban areas, revealing that the energy policy in the country had made no impact in the cooking energy sector. Recommendations for improving the energy supply situation were given and for removing the barriers that prevent the implementation of the recommendations.     

Thermal energy storage in building integrated thermal systems: A review. Part 1. active storage systems

Energy consumed by heating, ventilation and air conditioning systems (HVAC) in buildings represents an important part of the global energy consumed in Europe. Thermal energy storage is considered as a promising technology to improve the energy efficiency of these systems, and if incorporated in the building envelope the energy demand can be reduced. Many studies are on applications of thermal energy storage in buildings, but few consider their integration in the building. The inclusion of thermal storage in a functional and constructive way could promote these systems in the commercial and residential building sector, as well as providing user-friendly tools to architects and engineers to help implementation at the design stage. The aim of this paper is to review and identify thermal storage building integrated systems and to classify them depending on the location of the thermal storage system.     

Assess the potential of solar irrigation systems for sustaining pasture lands in arid regions – A case study in Northwestern China

The combined impact of global climate change and increasing human activities has led to the severe deterioration of grasslands in China. Using the solar irrigation systems is an effective way for sustaining pasture lands in arid regions. A solar irrigation system is the device that uses the solar cell from the sun’s radiation to generate electricity for driving the pump. And photovoltaic pump consists of an array of photovoltaic cells and pumps water from a well or reservoir for irrigation. Although ecologists and organizations constantly work and find ways to conserve grasslands through irrigation systems that use solar energy, issues on water resources are not yet thoroughly discussed. This paper takes into account the main factors in the study of water resources, including precipitation and groundwater, to analyze the feasibility of using a photovoltaic (PV) pumping irrigation. The appropriate area for such a PV pumping irrigation in Qinghai Province is also presented. The results show that the grasslands appropriate for PV pumping cover about 8.145 million ha, accounting for 22.3% of the grasslands in the entire province. Finally, the problems and countermeasures of PV pumping irrigation, including the impact on regional water balance, groundwater level and highland permafrost, are also considered.     

Report on the Photovoltaic R&D Program in Hawaii

Photovoltaic systems provide one of the best options to generate energy in Hawaii, a state that is more than 90 percent dependent on imported oil for its energy supply. Hawaii's excellent year-round insolation rates will contribute to the success of solar energy projects. The Hawaii Natural Energy Institute's program to accelerate utilization of PV power in Hawaii has thus far consisted of a continuation of a 50-year data base of solar insolation; an experimental program with grid-connected residential PV systems; and public information dissemination on PV technology and performance. HNEI is now developing a program that includes: (1) compiling a solar data base that includes a full solar resource assessment, with spectral analysis and measurement of direct insolation, (2) tests of various PV devices relative to insolation; (3) test and evaluation of contemporary PV powered systems (e.g. water pumping, refrigeration, communication and stand-alone residential applications) under various tropical island conditions; and (4) a technology transfer effort aimed at Hawaii and other Pacific Basin islands, including cost-benefit and market analyses.     

Municipal water supply dams as a source of small hydropower in Turkey

In Turkey the laws published in recent years succeeded in promoting the utilization of renewable energy for electricity generation. After the publication of Renewable Energy Law on 18 May 2005 in Turkey there occurred a boost in renewable energy projects along with hydropower development. Thus, the economically feasible hydropower potential of Turkey increased 15% and the construction of hydropower plants also increased by a factor of four in 2007 as compared to 2006. From this perspective, this paper was aimed to evaluate the small hydropower potential of municipal water supply dams of Turkey and discussed the current situation of SHP plants in terms of the government policy. It is estimated that the installing small hydropower plants to exiting 45 municipal water supply dams in Turkey will generate 173 GWh/year electric energy without effecting the natural environment. For a case study, Zonguldak Ulutan Dam and its water treatment plant has been investigated in detail.     

Is the concept of energy intensity meaningful?

Energy intensity, which is the quantity of energy contained in a unit of goods, can be defined in two ways: in terms of primary energy: and in terms of useful energy, ie at the output end of energy-using devices. The distinction between primary energy intensity and useful energy intensity is considered and two types of problem are addressed: those related to changes in the structure of production and those arising from the substitution of energy forms having different efficiencies. The importance of the concept of useful energy intensity is demonstrated: it allows us to analyse structural change in energy supply and situates our analysis at the level of satisfied needs.     

Life cycle water use of low-carbon transport fuels

In society’s quest to mitigate climate change it is important to consider potential trade-offs in climate solutions impacting other environmental issues. This analysis explores the life cycle water consumption of alternative low-carbon energy sources for transportation. Energy sources analyzed include both biofuels used in internal combustion engines and low-carbon electricity generation methods used in conjunction with electric vehicles. Biofuels considered are corn-based ethanol, soybean biodiesel, cellulosic ethanol from switchgrass, and microbial biodiesel. Electricity sources analyzed are coal with carbon sequestration, photovoltaic cells, and solar concentrators. The assessment method used is hybrid life cycle assessment (LCA), which combines materials-based process method and the economic input–output (EIO) method. To compare these technologies on an even footing the life cycle water use to propel a passenger vehicle one mile is estimated. All technologies evaluated showed an increase in water consumption compared to unleaded gasoline when water use from vehicle manufacturing was included. Scale-up calculations showed that mass adoption of electric vehicles and some configurations of algae and switchgrass systems could potentially contribute to the decarbonization of transportation with tolerable increases in overall water consumption. Irrigated crop based biofuels however were found to have significant potential impact on water resources when scaled up to macroscopic production levels.     

Optimization of operational planning for wind/hydro hybrid water supply systems

Water supply systems (WSS) frequently present high-energy consumption values, which correspond to the major expenses of these systems. Energy costs are a function of its real consumption and of the variability of the daily energy tariff.This paper presents a model of optimization for the energy efficiency in a water supply system. The system is equipped with a pump station and presents excess of available energy in the gravity branch. First, a water turbine is introduced in the system in order to use this excess of hydraulic available energy. Then, an optimization method to define the pump operation planning along the 24 h of simulation, as well as the analysis of the economic benefits resulting from the profit of wind energy to supply the water pumping, while satisfying the system constraints and population demands, is implemented, in order to minimize the global operational costs.The model, developed in MATLAB, uses linear programming and provides the planning strategy to take in each time step, which will influence the following hours. The simulation period considered is one day, sub-divided in hourly time steps. The rules obtained as output of the optimization procedures are subsequently introduced in a hydraulic simulator (e.g. EPANET), in order to verify the system behaviour along the simulation period. The results are compared with the normal operating mode (i.e. without optimization algorithm) and show that energy cost's savings are achieved dependently of the initial reservoir levels or volume. The insertion of the water turbine also generates significant economical benefits for the water supply system.     

China's energy and emissions outlook to 2050: Perspectives from bottom-up energy end-use model

Although China became the world's largest CO₂ emitter in 2007, the country has also taken serious actions to reduce its energy and carbon intensity. This study uses the bottom-up LBNL China End-Use Energy Model to assess the role of energy efficiency policies in transitioning China to a lower emission trajectory and meeting its 2020 intensity reduction goals. Two scenarios – Continued Improvement and Accelerated Improvement – were developed to assess the impact of actions already taken by the Chinese government as well as planned and potential actions, and to evaluate the potential for China to reduce energy demand and emissions. This scenario analysis presents an important modeling approach based in the diffusion of end-use technologies and physical drivers of energy demand and thereby help illuminate China's complex and dynamic drivers of energy consumption and implications of energy efficiency policies. The findings suggest that China's CO₂ emissions will not likely continue growing throughout this century because of saturation effects in appliances, residential and commercial floor area, roadways, fertilizer use; and population peak around 2030 with slowing urban population growth. The scenarios also underscore the significant role that policy-driven efficiency improvements will play in meeting 2020 carbon mitigation goals along with a decarbonized power supply.     

Impact of energy supply infrastructure in life cycle analysis of hydrogen and electric systems applied to the Portuguese transportation sector

Hydrogen and electric vehicle technologies are being considered as possible solutions to mitigate environmental burdens and fossil fuel dependency. Life cycle analysis (LCA) of energy use and emissions has been used with alternative vehicle technologies to assess the Well-to-Wheel (WTW) fuel cycle or the Cradle-to-Grave (CTG) cycle of a vehicle's materials. Fuel infrastructures, however, have thus far been neglected. This study presents an approach to evaluate energy use and CO₂ emissions associated with the construction, maintenance and decommissioning of energy supply infrastructures using the Portuguese transportation system as a case study. Five light-duty vehicle technologies are considered: conventional gasoline and diesel (ICE), pure electric (EV), fuel cell hybrid (FCHEV) and fuel cell plug-in hybrid (FC-PHEV). With regard to hydrogen supply, two pathways are analysed: centralised steam methane reforming (SMR) and on-site electrolysis conversion. Fast, normal and home options are considered for electric chargers. We conclude that energy supply infrastructures for FC vehicles are the most intensive with 0.03–0.53 MJ_eq/MJ emitting 0.7–27.3 g CO_2eq/MJ of final fuel. While fossil fuel infrastructures may be considered negligible (presenting values below 2.5%), alternative technologies are not negligible when their overall LCA contribution is considered. EV and FCHEV using electrolysis report the highest infrastructure impact from emissions with approximately 8.4% and 8.3%, respectively. Overall contributions including uncertainty do not go beyond 12%.     

Coupling of copper–chloride hybrid thermochemical water splitting cycle with a desalination plant for hydrogen production from nuclear energy

Energy and environmental concerns have motivated research on clean energy resources. Nuclear energy has the potential to provide a significant share of energy supply without contributing to environmental emissions and climate change. Nuclear energy has been used mainly for electric power generation, but hydrogen production via thermochemical water decomposition provides another pathway for the utilization of nuclear thermal energy. One option for nuclear-based hydrogen production via thermochemical water decomposition uses a copper–chloride (Cu–Cl) cycle. Another societal concern relates to supplies of fresh water. Thus, to avoid causing one problem while solving another, hydrogen could be produced from seawater rather than limited fresh water sources. In this study we analyze a coupling of the Cu–Cl cycle with a desalination plant for hydrogen production from nuclear energy and seawater. Desalination technologies are reviewed comprehensively to determine the most appropriate option for the Cu–Cl cycle and a thermodynamic analysis and several parametric studies of this coupled system are presented for various configurations.