Energy consumption, costs and environmental impacts for urban water cycle services: Case study of Oslo (Norway)

Energy consumption in the operation and maintenance phase of the urban water and wastewater network is directly related to both the quantity and the desired quality of the supplied water/treated wastewater - in other words, to the level of service provided to consumers. The level of service is dependent on not just the quantity and quality of the water but also the state of the infrastructure. Maintaining the infrastructure so as to be able to provide the required high level of service also demands energy. Apart from being a significant operational cost component, energy use also contributes to life-cycle environmental impacts. This paper studies the direct energy consumption in the operation and maintenance phase of the water and wastewater system in Oslo; and presents a break-up among the different components of the network, of quantities, costs and environmental impacts. Owing to the diversity in the periods of time for which comprehensive data for the whole system are available, the study period is restricted to years 2000-2006. The per-capita annual consumption of energy in the operational phase of the system varied between 220 and 260 kWh; and per-capita annual expenses on energy in inflation-adjusted year-2006-Euros ranged between 6.5 and 11 Euros. The energy consumed on the upstream, per unit volume water supplied was around 0.4 kWh on average, while the corresponding value for the downstream was 0.8 kWh per cubic metre wastewater treated. The upstream Greenhouse gas (GHG) emissions ranged between 70 and 80 g per cubic metre of water supplied, about 22% greater on average than the corresponding specific GHG emissions on the downstream.     

The evolution of flexibility mechanisms for achieving European renewable energy targets 2020—ex-ante evaluation of the principle mechanisms

In December 2008, the European Council and the European Parliament agreed on a final compromise for a new European renewable energy directive. One of the most debated issues prior to this compromise was the design of “target flexibility mechanisms”, which should allow member states with low or expensive renewable energy potential to partly fulfil their national renewable energy target in other countries. This article traces back the political discussion that has led to the evolution of the different flexibility options. It then evaluates the most prominent flexibility mechanisms against a set of qualitative criteria. It concludes that free or restricted certificate trade based on guarantees of origin (GOs) – as proposed earlier by the European Commission – is not a viable option due to some “knockout” criteria, despite other potential advantages. The mechanisms that have replaced GO trade in the final compromise – joint projects, joint support schemes and statistical transfer between member states – provide less flexibility, but score better against a number of other important criteria. The crucial question for the coming years is how their utilisation can be facilitated. One first step might be that proactive member states define open design issues for implementing the mechanisms.     

Modelling the impacts of electric vehicle recharging on the Western Australian electricity supply system

This study investigates the potential impacts of EVs on the Western Australian electricity grid, the constraints on the system’s capacity to supply electricity for EV recharging and the options for managing those potential impacts and constraints. Western Australia is geographically isolated and the electricity network has no interconnection with neighbouring regions. The State energy and vehicle markets are independent of issues occurring in neighbouring states. Western Australia is a relatively clean sample space. This study eliminates uncertainty in vehicle adoption rates from analysis by assuming that all new vehicles are EVs. This gives a worst case scenario in terms of load growth and shows that it will over 200,000 EVs, which represents 10% of the fleet, before there is any significant impact on peak demand even if charging behaviours are left unfettered. The study also shows, however, that the electricity supply and transmission industry can achieve significant short- and long-term benefits if vehicle charging behaviours are managed from the outset, through, for example, demand management or structured tariffs. In the short-term, providing incentive for off-peak recharging increases utilisation of existing transmission capacity, and cheaper, more efficient base-load generation infrastructure. In the long-term, investment in more underutilised capacity can be avoided.     

Global energy security and the implications for the EU

The following article will analyse the global and geopolitical dimensions of the future international energy security and its implications for Europe and the EU-27. In this context, I will discuss to which extent the EU's newly proclaimed “Energy Action Plan” of the EU Spring summit of 2007 and its declared common energy (foreign) policy are a sufficient strategy to cope with the new global and geopolitical challenges. The article concludes the following: (1) The interlinkage between globally designed traditional energy security concepts – that rely just on economic factors and “market-strategies” – and domestic as well as regional political stability demands new thinking with regard to both energy supply security and foreign and security policies. (2) Although after the Russian–Ukrainian gas conflict in January 2006, energy security has forced its way up the European energy and foreign policy agendas, the EU-27 member states have largely failed to forge a coherent European energy security and energy foreign policy strategy after their Spring summit of 2007 because its declared political solidarity has been still lacking. But the 2nd Strategic Energy Review of November 2008 has recommended new initiatives to overcome this lack by promoting concrete infrastructure and other projects for enhancing Europe's supply security and its political solidarity as part of a common energy (foreign) policy. If the EU is able to implement the March 2007 and November 2008 decisions, the EU oil and gas demand will drastically reduce and freeze at current levels. In this case, Putin's energy policies by using Russia's energy resources and pipeline monopolies as a political instrument to enforce its economic and geopolitical interests will be proved as self-defeating in Russia's long-term strategic interests. It will reduce Gazprom's gas exports to a much smaller EU gas market than originally forecasted as the result of a deliberate EU policy of decreasing its overall gas demand and by diversifying its gas imports.     

Water quality protection in bioenergy production: the US system of forestry Best Management Practices

United States federal law requires that states operate programs to address non-point source pollution. Forestry non-point source programs vary among states in their approach. Some states have laws that prescribe mandatory practices to control pollution, whereas other states use voluntary approaches of Best Management Practices (BMPs) and education and outreach programs. States routinely monitor the extent of BMP implementation so as to improve educational programs and thus improve implementation. Many states also have conducted studies to assess whether BMPs are effective in protecting water quality. A growing body of literature strongly suggests that properly implemented BMPs do protect water quality. A variety of private efforts, ranging from forestry certification systems to research support, are improving BMP implementation and effectiveness. BMPs developed for conventional forestry should be applicable to bioenergy systems. Bioenergy systems may include more frequent fertilization than conventional forestry, so managers must ensure that existing BMPs on fertilization and riparian management zones be fully implemented. Bioenergy systems using short-rotation woody crops will need careful implementation of BMPs for permanent roads and stream crossings.     

Promoting renewables in the energy sector of Tajikistan

Energy technology transfer can allow countries to move quickly to environmentally sound and sustainable practices. Integration of Renewable Energy Sources (RES) technologies in the energy sector of these countries can play a key role towards sustainability. The level of penetration of RES technologies remains seriously in arrears in Tajikistan, although the country has great RES potential. The aim of the paper is to look deeply into the most appropriate RES technology, which can be gradually introduced in the energy sector of Tajikistan and supported through demonstrations, business workshops, guides for installers with technical details and design proposals. The multi-dimensional methodology adopted included transparent decision support processes, using linguistic variables, taking into consideration the specific conditions prevailing in Tajikistan, as well as policy and technical proposal for the further development of the local market. Based on the results, the emphasis is laid on decentralized heat production, though the promotion of Solar Water Heaters, which seems to be an attractive energy option, with multiple benefits for the country.     

Multicriteria analysis to evaluate the energetic reuse of riparian vegetation

The management of riparian vegetation which includes cutting operations of grass, reeds, bushes and trees, is very important to reduce hydrogeologic risk.In Tuscany, riparian biomass and residues are mainly left shredded along courses or disposed in landfills as special wastes: actually different laws prohibit that tree trunks are abandoned in areas naturally affected by flooding, because they can be moved contributing to increase the water level and to maximize the hydraulic risk of some other nearby areas. In some cases, it is also possible to store the logs in specified sites from where they can be taken and used as a fuel in fireplaces or domestic heating plants.This work studies the possibility of the reuse of riparian vegetation as biomass for energy production and evaluates benefits and drawbacks from the economical, environmental and managerial points of view. Particularly, a specific methodology has been developed for two hydrological districts of Tuscany, with different typologies and densities of vegetation. First, an estimation of biomass distribution on the land and an evaluation of annual wood availability have been carried out; then, different chains concerning harvesting operation, biomass transport, storage conditions and final utilisation, have been defined and compared by a specific multicriteria analysis (MCA); finally, for the most suitable bio-energy chains the Life Cycle Assessment (LCA) has been implemented. Results of the LCA have also permitted to validate some environmental indicators used in the MCA, as mechanisation level of yards, energy efficiency of plants or transport distances.The decision making tool developed allows to compare costs and environmental benefits of the energy use of riparian vegetation, supporting local authorities involved in energy planning: in this way it is possible to confront different alternatives to match the energy demand and meet the energy saving and sustainability issues at the lowest cost for the community.In conclusion, the most interesting bio-energy chains, based on technology of direct combustion, are those that require a limited forestry mechanisation, the short transport distances and the medium sized plants. The LCA applied to these most suitable chains has also shown significant environmental benefits to promote the energetic use of riparian biomass instead of fossil fuels.     

All quiet on the eastern front? Disruption scenarios of Russian natural gas supply to Europe

The 2014 Russian–Ukrainian crisis reignited European concerns about natural gas supply security recalling the experiences of 2006 and 2009. However, the European supply situation, regulation and infrastructure have changed, with better diversified import sources, EU member states being better connected and a common regulation on the security of supply has been introduced. Nevertheless, European dependency on natural gas remained high. This paper investigates different Russian natural gas export disruptions scenarios and analyses short- and long-term reactions in Europe. We use the Global Gas Model (GGM), a large-scale mixed complementarity representation of the natural gas sector with a high level of technical granularity with respect to storage and transportation infrastructure. While we find that most of the EU member states are not severely affected by Russian disruptions, some East European countries are very vulnerable. Prioritizing the removal of infrastructure bottlenecks is critical for securing a sufficient natural gas supply to all EU member states.     

阶梯-深潭结构下的潜流交换过程试验研究

通过水槽试验验证了FLUENT结合COMSOL模拟阶梯-深潭结构下潜流交换过程的可行性,对比平坦河床,分析了阶梯-深潭结构下潜流的交换路径及不同区域的交换强度。结果表明,实测河床水沙界面水压力与模拟值吻合较好,阶梯坎附近呈现顺流下沉流、平行流、顺流上涌流、逆流上涌流4种水流状态。阶梯-深潭结构引起的水头变化是潜流交换的直接驱动力,阶梯坎上游及冲刷坑下游地表水进入河床后在冲刷坑内重回地表,完成了潜流交换过程。阶梯-深潭结构的潜流交换强度约为平坦河床的100倍,最大值出现在阶梯坎下方,最小值出现在阶梯坎下游约1m处的"速度零点"区域,该区域下游潜流交换速度明显减弱。     

2003年原油价格走势探讨

随着石油在国际政治经济领域地位的上升,2003年原油价格走势引起了世界范围的关注。文章对2003年世界石油市场的形势对价格的影响进行了预测,分析了美伊军事冲突对石油价格的影响。     

Electromagnetic transients in the control system of output parameters of a solar power plant in Tajikistan Central Asia region

At present, as the demand for electricity increases in all sectors, there is an urgent need to introduce alternative renewable energy sources into modern energy systems. Renewable energy sources, which consist of solar (photovoltaic, PV), wind and hydro power, are key alternative sources of “green energy’’ energies, but it can also be used to produce “green” hydrogen. Thanks to scientific and technological progress, the cost of photovoltaic solar radiation converters is constantly decreasing at a high rate, which makes it possible to build solar power plants of sufficiently large capacity. In the coming decades, solar energy will become an incentive for the economic development of countries that have the maximum “solar” resource. The Republic of Tajikistan is one of these countries with a high potential for solar energy.The article presents an analysis of the resources and potential of solar energy in the Republic of Tajikistan. The study of electromagnetic transients in networks with photovoltaic solar power plants is performed. The main equations, simulation model and calculations of transients are presented, taking into account changes in voltage on DC buses. An algorithm for controlling the system of automatic control of output parameters is proposed. The analysis of dynamic and static modes in parallel operation of a solar power plant with the grid is carried out. A block diagram and computer model is constructed in the MATLAB package together with Simulink and Power System Blockset.     

Potential of energy and water efficiency improvement in Abu Dhabi's building sector – Analysis of Estidama pearl rating system

Energy and water infrastructure in Abu Dhabi provides a strong example of the interconnection between energy and water, where the majority of its electricity and water demand is jointly produced from cogeneration plants. The total cost of fuel used for cogeneration plants are heavily depending on the efficiency level of end-use energy and water consumption. Buildings are the major electricity and water consumers with 84.6% and 92.2% respectively from the entire demand. The aim of this study is to analyze the energy and water consumption reduction by implementing Estidama pearl regulations and compare it with Business as Usual -the normal execution of things as they always do-for three sample buildings (villa, multistory residential and office building). For energy assessment, eQUEST software was used to examine the energy performance of the chosen buildings and to evaluate the energy saving potential after applying Estidama requirements. While for water assessment; Estidama and LEED calculation tools were used to do the same. The results of energy simulation and water analysis of the chosen buildings showed a potential of electricity reduction between 31% and 38% and a potential of water reduction between 22% and 36% depending on building type and other parameters. Also, a total monetary savings of 19 Billion AED can be achieved cumulatively over ten years period (2011–2020) after Estidama regulations have been applied. In addition, a reduction of 31.4 Million ton of CO₂eq cumulatively can be achieved.     

Assessing and mapping biomass potential productivity from poplar-dominated riparian forests: A case study

River systems are subjected to continuous physical changes as a result of their sediment transport. River dynamics is mainly determined by the seasonal variation of weather conditions and, together with the nature of the catchment and land management, affects flow patterns on a local scale. Riparian vegetation is well adapted to this periodical disturbance. It naturally regenerates on the new mineral soil created by the redistribution of river sediments during floods, playing an important role in the maintenance of streams and riverbanks stability. The high level of resilience and productivity of riparian tree species like Populus, contributes to the rapid biomass accumulation of riparian vegetation making these ecosystems of potential interest for biomass production for energy. This paper presents an operational methodology for investigating the biomass potential from riparian forests by coupling airborne laser scanning data and field survey. A case study on assessing and mapping biomass dynamics over a seventeen year period along a tract on the Paglia river, in Central Italy, is presented and discussed. The results highlight that the surface of the poplar-dominated riparian vegetation has significantly changed over the 1989–2006 period. More than 70 ha of new poplar forest were naturally regenerated during the analyzed period. The total amount of aboveground woody biomass of the riparian forest at the second inventory occasion has been estimated in 88 Mg ha⁻¹, evidencing a large amount of technically available resources for bioenergy production (around 80% of the standing woody biomass). The innovative strategy here proposed to assess and map at a very high spatial resolution the aboveground woody biomass of riparian forest meets the monitoring requirements to support energy production based on modern, non-conventional biomass harvest planning options.     

Which is the preferable biogas utilisation technology for anaerobic digestion of agricultural crops in Ireland: Biogas to CHP or biomethane as a transport fuel?

The utilisation of anaerobic digestion to produce biogas as an energy source is a mature technology in many European countries but is yet to be developed in Ireland. In 2009, the EU issued the Renewable Energy Source Directive 2009/28/EC which requires a 20% share of renewable energy sources (heat and electricity) in final energy consumption for all member states, respectively, including a 10% share of biofuels in the transport sector by 2020. The introduction of biogas to produce power and electricity in the form of CHP technology and biomethane as a transport fuel can help Ireland achieve the mandatory targets set by the directive. The key focus of the paper is to determine the optimum small to medium scale biogas technology and the impact the introduction of that technology infrastructure will have on renewable energy targets for Ireland. In terms of feedstock, agricultural sources such as energy crops and slurry offer a sustainable input to the anaerobic digestion process. The crop rotations under consideration consist of different arrangements of grass silage, maize silage and barley. Grass silage is found to be the most suitable crop for biogas energy production while biogas upgrading to biomethane as a transport fuel has the optimum technology potential in Ireland. To fuel a car operating on biomethane, 0.22 ha of grass land is required annually. Full scale national development of 5% of the area under grass in Ireland will contribute 11.4% of renewable energy to the total final transport energy demand by 2020, surpassing the target set by the Renewable Energy Source Directive 2009/28/EC.     

流域水生态恢复优先序判定方法及应用

为保证流域水生态补偿机制的实施功效,促进流域整体目标的协调发展,基于流域水生态恢复优先序判定理论,综合考虑自然资源、生态环境和经济社会要素,利用分段线性收益方程,借助环境判定矩阵进行流域物种组成和环境因素间的变量分析,提出了流域水生态恢复优先序判定方法,并将其应用于永定河官厅水库以上流域。结果表明,研究区河岸水生态自然状况得分的平均值为60.8,洋河张家口市和桑干河册田水库以下张家口市为生态修复的首选区域。这反映了实施生态补偿对流域水生态的改善具有促进作用。     

Algorithm for calculation and selection of micro hydropower plant taking into account hydrological parameters of small watercourses mountain rivers of Central Asia

Tajikistan and Kyrgyzstan are the two countries in Central Asia that have a huge reserve of hydro resources of the region. It is important to recognize the significance of the part played by the micro-hydropower plants (HPP) in the electric power generation in Tajikistan and Kyrgyzstan from the point of view of sustainable economic development. After all, the construction of micro-HPPs in mountainous areas will reliably ensure the development of small and medium-sized enterprises in the field of agriculture and livestock, industry, tourism, improve the social conditions of the population, as well as ensure the production of “green” hydrogen, which will contribute to the development of an environmentally friendly transport system in the regions. Micro HPPs gained recognition as a good alternative to traditional power generation for many developing countries around the world.This study presents a structural model and methodology of choice of a feasible type of micro HPP using the developed algorithm for calculation of hydro turbines’ characteristics based on the hydrological characteristics of small and shallow watercourses located in Central Asian countries, such as Kyrgyzstan and Tajikistan. Based on this model, the software “Calculation and choosing the type of hydro turbines for micro HPPs” has been developed. Depending on the load, a consumer can choose one of the suggested types of micro-hydroelectric power plants to meet his requirements. When choosing the type of micro-hydroelectric power station, a consumer should also take into account the factor of the seasonality of the water level, the constancy and speed of the water, and the volume of river water, since in some places the water freezes in winter.     

Co-firing biomass with coal for electricity generation—An assessment of the potential in EU27

The European Union aims to increase bioenergy use. Co-firing biomass with coal represents an attractive near-term option for electricity generation from renewable energy sources (RES-E). This study assesses the near-term technical potential for biomass co-firing with coal in the existing coal-fired power plant infrastructure in the EU27 Member States. The total technical potential for RES-E from biomass co-firing amounts to approximately 50–90 TWh/yr, which requires a biomass supply of approximately 500–900 PJ/yr. The estimated co-firing potential in EU27 amounts to 20–35% of the estimated gap between current RES-E production and the RES-E target for 2010. However, for some member states the national co-firing potential is large enough to fill the national gap. The national biomass supply potential is considerably larger than the estimated biomass demand for co-firing for all member states. About 45% of the estimated biomass demand for co-firing comes from plants located close to the sea or near main navigable rivers and indicates the possibility for biomass import by sea transport. Thus, biomass co-firing has the potential to contribute substantially to the RES-E development in EU27.     

黑河调水效果评价模型

针对黑河中游实施调水工程以来的情况，依据调水前后的相关数据，采用多种方法得出调水前后中游增泄下游水量的理论值和实测值；并通过对比分析评价了黑河调水和近期治理的效果，肯定了黑河中游实施调水工程后取得的成效。     

浊漳河流域水库群多目标生态调度模型研究

浊漳河流域水库群生态调度对改善浊漳河流域生态环境质量、满足经济社会需水要求有重要意义。综合考虑生态需水的处理差异,并针对各水库时间上目标的需水差异,提出一种利用分时段加权法处理多目标问题的方法,依据大系统分解协调技术求解了浊漳河流域多目标水库群优化调度模型。模型求解结果表明,在水库的调蓄能力范围内,模型在时间上处理了年际间缺水不平衡的情况,在空间上处理了下游共同承担的生态供水任务,并得出由关河水库承担较多的下游生态供水任务较优。通过模型调度,下游侯壁断面的平均年生态满足度可达到85.35%。研究成果可为流域水库群多目标生态调度提供参考。     

Oil and resource-backed aggression

A common misperception about oil politics is that it has a uniform, monolithic effect on policy development. This paper argues that in fact the net political effect of oil varies dramatically depending on the nature of the petrostate. It shows that oil income, when combined with revolutionary governments in petrostates, generates strong incentives for foreign policy aggression and international conflict. The aggressiveness of petro-revolutionary states is shown to have consequences in both military and economic spheres of international relations. Militarily, the aggressiveness of this type of state leads to a high rate of armed conflicts. Economically, the aggressiveness of petro-revolutionary states shapes global oil markets and international economic relations. The argument is tested using statistical analysis of international conflicts and economic sanctions. The policy implications are then considered, focusing on the negative global impacts of dependence on oil consumption.