Sizing and performance analysis of standalone hybrid photovoltaic/battery/hydrogen storage technology power generation systems based on the energy hub concept

In this study, the optimal sizing and performance analysis of a standalone integrated solar power system equipped with different storage scenarios to supply the power demand of a household is presented. One of the main purposes when applying solar energy resource is to face the increasing environmental pollutions resulting from fossil fuel based electricity sector. To this end, and to compare and examine two energy storage technologies (battery and hydrogen storage technology), three storage scenarios including battery only, hydrogen storage technology only and hybrid storage options are evaluated. An optimization framework based on Energy Hub concept is used to determine the optimum sizes of equipment for the lowest net present cost (NPC) while maintaining the system reliability. It was determined that the most cost effective and reliable case is the system with hybrid storage technology. Also, the effects of solar radiation intensity, the abatement potential of CO₂ emissions and converting excess power to hydrogen on the system’s performance and economics, were investigated and a few noticeable findings were obtained.     

Bulgaria Country Study to address climate change mitigation

Future developments of the Bulgarian economy, energy demand, energy supply, and greenhouse gas (GHG) emissions are projected and evaluated for baseline and mitigation scenarios. Different methods and approaches are used at different stages of the study with a tendency to incorporate them in a single integrated resource planning tool such as the MARKAL-MACRO model. The results obtained indicate that the aim of Framework Convention of Climate Change to have year 2000 GHG emissions below the base year 1988 emissions will be achieved without further mitigation steps. Reducing the expected increase of GHG emissions in the decade 2000 to 2010 requires a package of mitigation measures to be implemented in the next few years.

     

Using coal for transportation in China: Life cycle GHG of coal-based fuel and electric vehicle,and policy implications

This paper compares the GHG emissions of coal-to-liquid (CTL) fuels to the GHG emissions of electric vehicles (EVs) powered with coal-to-electricity in China. A life cycle model is used to account for full fuel cycle and use-phase emissions, as well as vehicle cycle and battery manufacturing emissions. It is found that the reduction of life cycle GHG emissions of EVs charged by electricity generated from coal, without utilizing carbon dioxide capture and storage (CCS) technology can be 3–36% when compared to petroleum-based gasoline car. The large range in emissions reduction potential is driven by the many different power generation technologies that are and could in the future be used to generate electricity in China. When CCS is employed in power plants, the GHG emission reductions increase to 60–70% compared to petroleum-based gasoline car. However, the use of coal to produce liquid transportation fuels (CTL fuels) will likely lead to significantly increased life cycle GHG emissions, potentially 30–140% higher than petroleum-based gasoline. When CCS is utilized in the CTL plant, the CTL fueled vehicles emit roughly equal GHG emissions to petroleum-based gasoline vehicles from the life cycle perspective. The authors conclude that policies are therefore needed in China in order to accelerate battery technology and infrastructural improvements for EV charging, increased energy efficiency management, and deployment of low-carbon technologies such as CCS.     

The environmental life cycle assessment of agricultural sector in Thailand: EIO‐LCA approach

Agriculture is one of the major sectors in Thailand, with more than half of the population employed in agriculture‐related occupations. This study evaluated energy consumption and greenhouse gas (GHG) emissions of the Thai agricultural sector by applying the economic input–output life cycle assessment (EIO‐LCA) approach. The model evaluates the entire agricultural sector supply chain. Based on one million Thai baht (approximately $27,800 U.S. dollars) final demand of the rice paddy sector, the carbon dioxide (CO₂) emissions from the electricity sector are responsible for 27% (1,246 kilograms [kg] CO₂) of the total CO₂ emissions, whereas the emissions from paddy activities associated with the fertilizers and pesticides sector account for 16% (760 kg CO₂) and 11% (513 kg CO₂), respectively. The top three largest GHG emissions from the total agricultural sector supply chain are associated with the oil palm, the coffee and tea, and the fruit sectors. The government should promote and encourage sustainable agriculture by reducing the use of fertilizers and pesticides and by utilizing energy‐saving technologies.     

Quantifying the Impact of Renewable Energy Futures on Cooling Water Use

This article presents an empirically based model, WiCTS ( Wi thdrawal and C onsumption for T hermoelectric S ystems), to estimate regional water withdrawals and consumption implied by any electricity generation portfolio. WiTCS uses water use rates, developed at the substate level, to predict water use by scaling the rates with predicted energy generation. The capability of WiCTS is demonstrated by assessing the impact of renewable electricity generation scenarios on water use in the United States (U.S.) through 2050. The energy generation scenarios are taken from the Renewable Energy Futures Study performed by the U.S. National Renewable Energy Laboratory of the U.S. Department of Energy. Results indicate reductions in water use are achieved under these renewable energy scenarios. The analysis further explores the impact of two modifications to the modeling framework. The first modification presumes geothermal and concentrated solar power generation technologies employ water‐intensive cooling systems vs. cooling technology that requires no water. The second modification presumes all water‐intensive cooling technologies use closed cycle cooling (as opposed to once‐through cooling) technologies by 2050. Results based on one of the renewable generation scenarios indicate water use increases by over 20% under the first modification, and water consumption increases by approximately 40% while water withdrawals decrease by over 85% under the second modification.     

Global energy and emissions scenarios for effective climate change mitigation—Deterministic and stochastic scenarios with the TIAM model

The achievement possibilities of the EU 2 °C climate target have been assessed with the ETSAP TIAM global energy systems model. Cost-effective global and regional mitigation scenarios of carbon dioxide, methane, nitrous oxide and F-gases were calculated with alternative assumptions on emissions trading. In the mitigation scenarios, an 85% reduction in CO₂ emissions is needed from the baseline, and very significant changes in the energy system towards emission-free sources take place during this century. The largest new technology groups are carbon-capture and storage (CCS), nuclear power, wind power, advanced bioenergy technologies and energy efficiency measures. CCS technologies contributed a 5.5-Pg CO₂ annual emission reduction by 2050 and 12 Pg CO₂ reduction by 2100. Also large-scale forestation measures were found cost-efficient. Forestation measures reached their maximum impact of 7.7 Pg CO₂ annual emission reduction in 2080. The effects of uncertainties in the climate sensitivity have been analysed with stochastic scenarios.     

夹点技术--一种有效的清洁生产方法

夹点技术作为一种有效的清洁生产措施可用于能源优化、资源节约、废物减量及污染防治等方面，能收到良好的经济效益和环境效益。本文介绍夹点技术的基本原理、应用研究领域及其发展趋势。     

Assessing the potential of yield improvements, through process scrap reduction, for energy and CO2 abatement in the steel and aluminium sectors

Targets to cut 2050 CO₂ emissions in the steel and aluminium sectors by 50%, whilst demand is expected to double, cannot be met by energy efficiency measures alone, so options that reduce total demand for liquid metal production must also be considered. Such reductions could occur through reduced demand for final goods (for instance by life extension), reduced demand for material use in each product (for instance by lightweight design) or reduced demand for material to make existing products. The last option, improving the yield of manufacturing processes from liquid metal to final product, is attractive in being invisible to the final customer, but has had little attention to date. Accordingly this paper aims to provide an estimate of the potential to make existing products with less liquid metal production.Yield ratios have been measured for five case study products, through a series of detailed factory visits, along each supply chain. The results of these studies, presented on graphs of cumulative energy against yield, demonstrate how the embodied energy in final products may be up to 15 times greater than the energy required to make liquid metal, due to yield losses. A top-down evaluation of the global flows of steel and aluminium showed that 26% of liquid steel and 41% of liquid aluminium produced does not make it into final products, but is diverted as process scrap and recycled. Reducing scrap substitutes production by recycling and could reduce total energy use by 17% and 6% and total CO₂ emissions by 16% and 7% for the steel and aluminium industries respectively, using forming and fabrication energy values from the case studies. The abatement potential of process scrap elimination is similar in magnitude to worldwide implementation of best available standards of energy efficiency and demonstrates how decreasing the recycled content may sometimes result in emission reductions.Evidence from the case studies suggests that whilst most companies are aware of their own yield ratios, few, if any, are fully aware of cumulative losses along their whole supply chain. Addressing yield losses requires this awareness to motivate collaborative approaches to improvement.     

青岛市大气环境质量状况分析与评价

对青岛市大气主要污染物变化趋势进行了分析,并利用模糊综合评价模型对各年大气环境质量状况进行了综合评价。研究结果表明:近10年来青岛市大气环境质量处于尚清洁状况,且在不断改善;受工业扬尘和建筑扬尘影响,青岛市主要污染物是可吸入颗粒物PM10;以煤炭为主的能源结构加之落后的工艺设备等原因使得大气中二氧化硫浓度一直处于较高水平;随着青岛市机动车保有量的增长,以氮氧化物为特征的机动车尾气污染日趋明显,因此,冬季采暖燃煤利用、机动车尾气控制及城市扬尘抑制仍是青岛市未来大气污染的治理重点,强化燃煤脱硫技术和改善机动车尾气排放是青岛市大气环境质量改善的关键。     

中原经济区能源消费视角下的大气环境压力评估

研究以能源消费模式为切入点,分析中原经济区能源消费总量、消费结构和利用效率的现状水平,并分析能源消费引起的大气环境压力状况。基于经济发展速度调控及节能减排力度的不同,设置2020年三种能源消费情景,使用区域能源消费总量优化模型模拟预测不同情景下的能源消费总量,并分析不同情景下的大气环境压力。结果表明,快速发展和适度发展Ⅰ情景下,2020年区域能源消费总量将比2012年增加4.2×10~8tce和2.4×10~8tce,煤炭消费总量将增加3.1×10~8tce和1.2×10~8tce,大气污染物排放压力增加30%和50%;适度发展Ⅱ情景下,能源消费总量将增加0.2×10~8tce,煤炭消费总量将下降0.3×10~8tce,大气污染物排放压力将降低20%。因此,要实现经济发展稳步增长(年均增长率7.7%)和大气污染物排放总量削减10%目标,重中之重是实现煤炭消费总量"零增长"或"负增长",同时力争能源消费总量控制在5×10~8~6×10~8tce,凭借煤炭占比大幅下降(降至65%左右)最大限度发挥能源供给领域节能效应,依靠产业结构升级节能效应和技术节能拓展能源消费领域节能空间,将能效水平提高至0.6tce/万元以下。     

Co-production of hydrogen and electricity with CO2 capture

Electricity and hydrogen can be used as energy carriers to reduce emissions of CO₂ from small and mobile energy users. One of the most promising technologies for the production of electricity and hydrogen with low CO₂ emissions is coal gasification with CO₂ capture and storage. Performance and cost data are presented for plants which produce electricity and hydrogen alone and plants which co-produce both of these energy carriers. The co-production plants include plants which produce a fixed ratio of hydrogen to electricity and plants which are able to vary the ratio while continuing to operate the gasification and CO₂ capture parts of the plant at full load. The paper also assesses the ability of these types of plants to satisfy the varying demands for hydrogen and electricity in future energy supply systems. The lowest cost option for the scenarios assessed in the paper is the use of flexible co-production plants with underground buffer storage of hydrogen.     

Analysis of energy security and sustainability in future low carbon scenarios for Brazil

This study estimated a series of indicators to assess the energy security of supply and global and local environmental impacts under different mitigation scenarios through 2050 in Brazil, designed with the integrated optimization energy system model MESSAGE‐BRAZIL. The assessment of interactions between environmental impacts and energy security dimensions was complemented through the application of life cycle assessment (LCA) methodology. Overall results imply energy security establishes more synergies than trade‐offs in increasingly stringent mitigation scenarios, especially patent within the sustainability dimension, which increases energy security and provides additional benefits regarding climate change mitigation and air pollution emissions. It is still necessary to extend analysis to other energy sectors in addition to the power supply sector and to promote a better understanding of repercussions of energy scenario expansion in energy security.     

Comparing Scales of Environmental Effects from Gasoline and Ethanol Production

Understanding the environmental effects of alternative fuel production is critical to characterizing the sustainability of energy resources to inform policy and regulatory decisions. The magnitudes of these environmental effects vary according to the intensity and scale of fuel production along each step of the supply chain. We compare the spatial extent and temporal duration of ethanol and gasoline production processes and environmental effects based on a literature review and then synthesize the scale differences on space–time diagrams. Comprehensive assessment of any fuel-production system is a moving target, and our analysis shows that decisions regarding the selection of spatial and temporal boundaries of analysis have tremendous influences on the comparisons. Effects that strongly differentiate gasoline and ethanol-supply chains in terms of scale are associated with when and where energy resources are formed and how they are extracted. Although both gasoline and ethanol production may result in negative environmental effects, this study indicates that ethanol production traced through a supply chain may impact less area and result in more easily reversed effects of a shorter duration than gasoline production.     

GEOTHERMAL ENERGY IN TRANSITION

At a time when future sources of energy are under close scrutiny, both in terms of availability and suitability, geothermal energy ranks among the candidates for inclusion in any appraisal of alternative forms of supply. The use of geothermal energy for the production of electricity and for supplying domestic and industrial heat is a comparatively recent phenomenon, and its application remains closely constrained by favourable geological conditions. Yet exploration in several countries shows that geothermal energy may emerge as an important adjunct to total energy supply in many localities. McNitt outlines some of the economic and technological parameters of this energy source. Small scale geothermal power stations are more economic and less capital intensive than conventional plants, which make them of particular interest for developing countries with small electricity systems and competing demands on limited capital resources. The principal capital expenditures in the development of geothermal sources include exploration, steam production, installation of generating plant and the cost of effluent disposal. The wider use of low grade geothermal heat is also examined, in addition to the environmental problems occurring to the development of geothermal energy. The scope for technical co-operation in the development of geothermal energy is substantial, and it is likely that this source of energy will undergo more intensive development on the local scale in the future.     

Application of life-cycle assessment to type III environmental declarations

The objective of this research is to develop a desirable type III environmental declaration format for the industrial consumer. A total of five different scenarios were chosen for the presentation of life-cycle assessment results in a format that meets the requirements of a type III environmental declaration. Life-cycle assessment of an electronic component was performed for this purpose. Environmentally significant impact categories and input/output items of a product system derived from the life-cycle assessment are presented in this format. Presenting these information concisely in a standardized format would accelerate the communication of environmental aspects of materials and components in a product supply chain. Thus the type III environmental declaration can be a useful instrument for the manufacturing of an ecoproduct.     

Cars and fuels for tomorrow: a comparative assessment

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.     

Life cycle assessment of a pulverized coal power plant with post-combustion capture, transport and storage of CO2

In this study the methodology of life cycle assessment has been used to assess the environmental impacts of three pulverized coal fired electricity supply chains with and without carbon capture and storage (CCS) on a cradle to grave basis. The chain with CCS comprises post-combustion CO₂ capture with monoethanolamine, compression, transport by pipeline and storage in a geological reservoir. The two reference chains represent sub-critical and state-of-the-art ultra supercritical pulverized coal fired electricity generation. For the three chains we have constructed a detailed greenhouse gas (GHG) balance, and disclosed environmental trade-offs and co-benefits due to CO₂ capture, transport and storage. Results show that, due to CCS, the GHG emissions per kWh are reduced substantially to 243 g/kWh. This is a reduction of 78 and 71% compared to the sub-critical and state-of-the-art power plant, respectively. The removal of CO₂ is partially offset by increased GHG emissions in up- and downstream processes, to a small extent (0.7 g/kWh) caused by the CCS infrastructure. An environmental co-benefit is expected following from the deeper reduction of hydrogen fluoride and hydrogen chloride emissions. Most notable environmental trade-offs are the increase in human toxicity, ozone layer depletion and fresh water ecotoxicity potential for which the CCS chain is outperformed by both other chains. The state-of-the-art power plant without CCS also shows a better score for the eutrophication, acidification and photochemical oxidation potential despite the deeper reduction of SO_x and NO_x in the CCS power plant. These reductions are offset by increased emissions in the life cycle due to the energy penalty and a factor five increase in NH₃ emissions.     

环渤海地区碳排放影响因素分解及其差异研究

在Kaya公式的基础上对环渤海地区碳排放影响因素进行了分解,并对各省市碳排放状况进行了对比分析。结果发现,环渤海地区碳排放量大致呈现持续均匀的增长趋势。其碳排放主要受能源结构、碳排放系数、能源强度、产业结构、经济规模5个因素影响。各省市碳排放量均呈加速增长趋势,能源结构仍以煤炭为主,产业结构有待优化。结合研究结果,从加强低碳技术创新、优化能源消费结构、开发绿色能源、宣传低碳观念角度提出了相关碳减排建议。     

Multiscale approach to the security of hardware supply chains for energy systems

While the cybersecurity field has focused primarily on software and network security, threats and vulnerabilities of hardware device supply chains are growing concerns. Of particular importance and interest in this vein is the way in which semiconductors and other electronic devices are increasingly deployed to support energy distribution, storage, and control at a variety of scales. Future smart grid supply chains must be secured to prevent cyber attacks from affecting energy infrastructure, and the societal and economic functions on which they depend. This perspective paper calls for a multiscale approach to address modeling and decision-making for energy system hardware supply chains. A multiscale approach, as discussed in this paper, can facilitate resilience of supply chains across the life cycles of these systems, through low- and high-tech techniques to monitor and act on the supply chain. This can incorporate both qualitative and quantitative factors to suit the variety of stakeholders, geographic scales, organizational levels, and planning and operational time horizons.