Bioenergie – Beitrag zum heutigen und zukünftigen Energiesystem

The introduction and establishment of renewable energies is still discussed intensively with the focus on climate-neutral coverage of the global energy demand. In this regard it is a valid option to use biomass as a feedstock. Already today biomass contributes significantly to cover the energy demand in the global energy system. Therefore, the present and future global bioenergy potentials are investigated in the following and compared to the respective biomass use. The results show, amongst others, that the share of biomass for heat, electricity and fuel production will increase worldwide until 2030, although the availability of biomass for energy production is likely to decline in the future.     

The interface of the energy and forest sectors—Potential players in the bioenergy business

The upcoming bioenergy business area opens up promising opportunities for the traditional energy and forest sectors. This has motivated us to study existing and potential bioenergy actors that could take up this unique opportunity and develop new business around the “green gold” of the forest. Light is shed on the interface between the energy and forest sectors through a comparison of the most focal bioenergy actors with traditional forest and energy companies. The analytical methods used include both parametric and nonparametric analysis of variance, and cluster analysis. The result is a better understanding of the players that have the potential to capitalize on the emerging business.     

The effect of spatial variables on the economic and environmental performance of bioenergy production chains

The aim of this paper is to understand the impacts of spatial variables on the performance of bioenergy production chains (BPCs). Even though the strong debates continue on the use of first generation biomass for bioenergy production, many countries continue to utilize it as an alternative energy source. Several studies have been carried out on biomass transformation efficiency, on environmental impacts of using crop in biofuel production, and on its negative effects on increasing food prices. However, less attention has been paid to the role played by the spatial variables on the performance measures of BPCs.In this paper, we analyse how three spatial variables, i.e. cultivation area size, land dispersion, and accessibility to cultivation areas, can affect the performance of energy-balanced BPC, which produces its own electric and thermal energy demand. The chain is represented as a network of processes, where all inputs and outputs are geographically referred and analysed in a theoretical case example. We propose an enterprise input-output (EIO) model, which can be used as an accounting tool to compute the main materials and energy flows-related costs and as a planning tool to evaluate the chain performance in different scenarios. Finally, the proposed model is applied to an actual case study, to investigate the opportunity to establish a sunflower-based BPC in Apulia region (Italy) and to assess its performance.Results show that higher land dispersion degree and less area accessibility levels reduce the economic and environmental performance of the BPCs. The construction of the energy-balanced chain reduces the negative environmental impacts caused by fossil energy use in the processes of the BPC. Managerial implications can also be obtained from actual case study about the biodiesel plant location decisions.     

基于混合储能的直流微网母线电压控制策略

为了平抑风力发电接入直流微电网的功率波动问题,满足负荷持续高质量供电需求,对由锂电池和超级电容器组成的混合储能系统进行了研究。以超级电容电压和锂电池荷电状态为约束条件,将储能系统平衡所需的功率差分为低频与高频部分;锂电池用于吸收和释放低频部分,超级电容用于吸收和释放高频部分,使风机整流器工作在恒压状态,采用电压外环、电流内环双闭环控制,以直流母线的电压稳定为目标,维持系统功率平衡。仿真结果表明,所提混合储能系统控制策略具有较快的动态响应速度和较好的控制性能,可很好地满足负载功率需求,稳定直流母线电压。研究结果可为分析规模化新能源接入直流微网系统的稳定问题提供参考。     

主要经济体低碳技术国际合作及其启示

面对日益严峻的全球气候变化形势和日趋紧迫的温室气体减排要求,全球主要经济体加强了在低碳与气候友好技术领域的国际合作,推出了主要经济体能源与气候论坛技术行动计划。技术行动计划集中关注了先进汽车、生物质能利用、碳捕集利用与封存、建筑部门提高能效、工业部门提高能效、高效低排放燃煤、海洋能利用、智能电网、太阳能利用和风能利用等10项低碳与气候友好技术。我国在技术行动计划中应以终端用能技术、核能技术为重点,在碳捕集利用与封存领域做好技术储备,在不同阶段采取财政补贴和排放交易的政策促进低碳与气候友好技术的发展。     

Bioenergie im globalen Energiesystem Möglichkeiten und Grenzen

Biomass as a source of energy becomes more and more important world wide. At the same time the demand for food and fodder as well as for renewable raw material is increasing significantly. On this background the goal of this paper is it to discuss based on a presentation of the world wide energy system the potentials of an energy provision from biomass and to discuss these potentials within the context of the dimensions of the global energy system. Based on these data statements are made under which circumstances the contribution of biomass within the energy system can be increased.     

Elektroautos in einer von erneuerbaren Energien geprägten Energiewirtschaft

The German Federal Government wants to establish Germany as a leading market for electric mobility. Potential environmental benefits and changes in the economic framework conditions of the energy sector are described in this paper. In order to quantify the electricity split which is actually used for charging electric vehicles, two economic models for the energy sector, a model for the market penetration of electric vehicles, a vehicle model and an LCA model are brought together. Based on an assumed dynamic increase of electric vehicles to 12 million in 2030, an additional electricity demand of about 18 TWh is calculated. If the vehicles are charged directly after their last daily trip, the peak load increases by 12%—despite the small increase in electricity demand. First model calculations for the development of the European power generation system show that the direct impact on the construction of new power plants remains low even until 2030. An impact of electric mobility on CO₂ certificate prices can only be seen from 2025 onwards and is limited to an increase in certificate prices by a maximum of 8 % in 2030. An optimisation is possible with intelligent charging strategies: The peak load without demand side management can be reduced by 5 GW and about 600 GWh of additional wind energy can used which would otherwise have been throttled due to feed-in management—about 3.5 % of the total electricity demand of electric vehicles. On the other hand, demand side management leads to more coal power plants instead of gas power plants being used to meet the additional electricity demand. If additional renewable sources are installed along with demand side management, the electricity for electric vehicles is almost carbon free. This is also reflected in the life cycle balance of electric vehicles which also includes vehicle and battery production: With today’s average electricity split in Germany, the greenhouse gas emissions of electric vehicles are about comparable to vehicles with conventional combustion engines. However, the electricity split in 2030 or the use of additional renewable energy sources lead to a significant advantage in the greenhouse gas balance.     

Techno-ökonomische Bewertung von Energie-Autarkie für die Energieversorgung von Einfamilienhäusern

Many consumers currently follow the idea of energy self-sufficiency and try to contribute to meet their energy needs in order to become independent and self-sufficient from the central power supply system. In order to achieve load-oriented energy self-sufficiency the provision of energy must cover the full energy demand at any time. Against this background, in this paper the costs and potentials of a load-oriented energy self-sufficiency of single-family homes are analysed. Thereby it is differentiated between electricity-, heat- and energy self-sufficiency. The modelling is carried out with the simulation environment ?Polysun Designer“ which allows a high temporal dynamic simulation of the annual energy demand and supply.The results show that, within the investigated supply variations, the highest levels of energy self-sufficiency can be achieved by an energy supply system completely based on electricity using a combination of PV; heat pump and battery storage. Depending on the building standard, a maximum of 45 (existing buildings) and 71?% (new buildings) of the building’s energy demand can be covered with renewable energy. The economic evaluation however has shown that under present conditions, none of the investigated supply variants can compete with conventional energy supply (public grid connection + gas condensing boiler).     

一种清洁能源与市政热网互补的供热系统设计及模拟研究

北方地区的建筑供暖需求随着城市建筑面积的迅速增长而不断增加,而城市热网改扩建缓慢,供热能力不足,距城区较远的新建及改扩建小区的供暖需求面临挑战,并且供暖带来的高能耗及环境污染问题日益严峻。针对此类问题,提出了将太阳能、空气能与传统市政热网相结合、互为补充的清洁能源与市政热网多能互补的集中供热系统,利用TRNSYS软件建立系统模型,设计系统5种不同的运行模式及相应的运行控制策略,并以石家庄市某新建小区为例进行分析。模拟运行结果表明,在整个供暖季中,运行时间较长的是太阳能辅助双热源(水源)热泵供热模式和双热源(空气源)热泵供热模式,清洁能源的供热比例为82.15%,热泵机组效率高,平均COP为4.06,远高于常规的热泵机组。研究结果可为周边供热能力不足的新建及改扩建小区选择供热系统提供参考。     

Beitrag von technologischen und strukturellen Veränderungen im Energiesystem der EU-27 zur Erreichung ambitionierter Klimaschutzziele

To stabilise the concentration of GHG (Greenhouse gases) in the atmosphere to a level of 450ppm (parts per million), a strong climate policy in the EU-27 will be required. The target is achievable through a 71% reduction of GHG emissions from 1990 emission levels by the year 2050. With the regionalised Pan-European TIMES energy system model, the role of technologies with regard to efficiency improvement, fuel switching and energy saving measures will be analysed under such an emission reduction target. The Pan-European TIMES model illustrates in detail the whole energy system of the different member states of the EU-27 plus Iceland, Norway and Switzerland. The limited resource and import potentials of different energy carriers, the competition of the use of energy carriers among different sectors and the country specific differences in energy demand will be taken into account. The results show that the energy consumption of the EU is influenced rather by political targets and positions related to climate protection, security of supply and the use of nuclear energy than by the available technological options. Under a climate protection scenario with restricted use of nuclear energy, the most commonly used options are to increase the use of renewable energy in all sectors, produce electricity in combination with carbon capture and storage (CCS) and to increase the use of electricity over other fuel sources in the demand sectors. Furthermore, technological improvements will be required throughout the entire energy system if political targets are to be successfully realised.     

Energy and irrigation in LDCs

Climatic conditions prevailing in most developing countries determine that much of the annual rainfall is seasonal. There are regular dry spells which last anything from a few weeks to several months and sometimes even longer. If developing countries are to achieve greater self-sufficiency in food production, then irrigation must play a vital role. But irrigation is energy intensive and some energy sources are a dwindling asset. On the other hand there is a continually rising demand for food which automatically produces a corresponding increase in energy requirements. The question this poses then is, if continuity of food production is to be assured, on what energy system should irrigation development be based? Alternatively, how can expendable sources of energy be most economically used?     

防范我国能源供给体系失灵的公共政策

中国经济发展面临一个长期难题是能源供给小于能源需求。安全的能源供给体系,是中国经济健康持续发展的重要保证。煤炭为主的能源供给结构,需要优化和调整。用财政税收政策鼓励企业降低能源消耗,建立能源储备体系,可以很好地防止中国能源供给失灵,确保国家能源供给安全。     

Food,energy and environment: Is bioenergy the missing link?

We study price linkages between the food, energy and bioenergy markets. A vertically integrated multi-input, multi-output market model allows us to derive testable hypothesis, which we test by applying time-series analytical mechanisms to nine major traded food commodity prices along with one weighted average world crude oil price. The data consists of 939 weekly observations from January 1993 to December 2010. The empirical findings confirm the theoretical hypothesis that the prices for crude oil and food commodities are interdependent: a USD 1/barrel increase in oil prices and food commodity prices increase by between USD 0.09/tonne and USD 1.65/tonne.     

Geothermisch erschlie?bare Niedertemperaturw?rmesenken in Deutschland – Identifikation und Quantifizierung

Geothermal energy supply meets the expectations of the established criterias for sustainability from the German government because it provides a base load of electricity- and heat supply by nearly zero emissions. The geothermal resources in Germany are big enough to cover a relevant demand of the German energy supply. Due to the low electrical efficiency is a high amount of heat produced what can be feed in a distribution network. In this context the aim of the following article is to identify and quantify the technical and economical low temperature heat demand for sector household, trade and industry in local authorities bigger then 20?000?inhabitants for German areas with geothermal recourses. The technical low temperature heat demand is calculated to 341?TWh/a (241?TWh/a household, 19?TWh/a trade, 81?TWh/a industry), 206?TWh/a of this heat demand is deducible by geothermal energy and 26?% of the geothermal deducible heat demand can be used on economic conditions.     

21世纪初我国能源安全的战略选择

在对我国2020年以前能源供需形势和能源安全面临的挑战的分析基础上,深入分析了美国、欧盟、日本、印度等国家和地区能源安全战略的基本取向,结合国情提出了我国应选择的能源安全战略模式和供应体系的建设构想,即确立自主、开放型的能源安全模式,构建"国内能源勘探开发生产、进口能源供应和国内能源战略储备"三位一体的能源供应体系,采取配套的战略保障措施。     

天然气开启能源新时代——第25届世界天然气大会综述

2012年6月4-8日,第25届世界天然气大会在马来西亚首都吉隆坡举行,会议以“天然气:可持续发展的未来全球能源增长点”为主题,交流总结了2009-2012年以来天然气领域的发展现状和未来趋势.认为天然气逐步成为一次能源结构中不可替代的清洁能源;非常规天然气开发将改变世界天然气供需格局,成为推动天然气发展的重要因素;未来20年LNG需求将增加一倍多,北美LNG出口将影响世界贸易格局;全球天然气价格将以区域性价格体系为主,近期难以形成统一气价;天然气消费需求的增长及能源消费结构的调整加大了对储气库的需求;俄罗斯推行天然气出口新策略,纳布科管道项目遏阻;人力资源竞争激烈,人才是天然气工业可持续发展的重要驱动力 中国的天然气发展势头迅猛,市场空间广阔,将为世界天然气市场的发展注入新的活力.     

Bewertungskriterien einer optimierten Energieversorgung regionaler Verbünde mit hohen Anteilen erneuerbarer Erzeugung

To determine an optimum economic solution for a renewable energy supply, an integral consideration of the system would be desirable. Because the difficulty of implementation increases with the number of stakeholders involved, locally optimized sub systems could accelerate the change in energy supply, albeit the global optimum might not be reached. An enhanced regional self-sufficiency could be a conceivable measure to increase public acceptance for interventions in the energy supply system. In this paper different ratios for quantification and illustration of the improvement of an optimized energy supply are defined. The effectiveness of demand side management, flexibly operated cogeneration units and energy storages are examined. The results are compared with those of a systematic throttling of producers during peak times. The calculations are performed within the Regenerative Modellregion Harz project, one of six model regions that are supported by the Federal Ministry of Economics and Technology and the Federal Ministry for Environment, Nature Conservation and Nuclear Safety within the E-Energy-initiative. The potential for increasing the internal consumption and the ratio of self-supply of the listed residual load smoothing methods can be determined. The reduction of maximum imports and exports by demand side management and flexibly operated cogeneration units prove to be comparatively small. A greater effect on the level of residual loads can be achieved by the use of storage power plants and especially power-to-gas because of the technology??s high storage capacity. A strong decrease of maximum exports can be realized by systematic reduction of production during peak times. The required grid capacities can almost be cut in half by using 99 instead of 100 percent of the power generation potentials.     

Ein Rollenmodell zur Einbindung der Endkunden in eine smarte Energiewelt

The successful expansion of renewable energies requires a phase of change in the energy supply system. On the one hand solutions have to be found to ensure the system dependability in spite of the high volatility of the feeding-in from renewable sources. On the other hand the differences between feeding-in and demand, which also occurs on the regional level evermore, have to be equalized on the regional level, too. For this purpose, it is necessary to develop new control and modified market mechanisms. The role definition of the involved actors gets an increasing relevance because of the politically predetermined unbundling. However, only a slight attention was paid to the role of the final consumers in the past. For a successful rebuilding of the energy supply system it is nevertheless important to involve the consumers in this process. It could be demonstrated within the research project “MeRegio”, that the integration of the consumers into an incentive based demand side management can tap significant potentials to equalize differences between feeding-in and demand. Therefore, the focusing on the final consumers can have an important contribution to rebuild the energy supply system.     

中国城镇化进程的能源供应时空协调研究

城镇是现代社会财富积累的中心。随着城镇化发育不断走向成熟,城镇的生存和发展对能源消费的依赖日趋强烈。这种消费需求不仅体现在总量增长方面,更体现在质量提高方面。然而,由于全球矿物燃料资源存在着明显的空间收敛特征,因此当国家在城镇化过程中不断寻求更高质量能源以满足自身消费需求时,国家能源供应保障体系的发育空间便迅速从区域或国家转向全球。这就是国家城镇化能源供应保障空间时空协调的基本内涵所在。换言之,只有在消费需求增长(时间过程)与供应范围有效扩展(空间过程)两者的有机协调时,国家城镇化发育的能源供应保障体系才能真正建立。中国的实践恰恰证明了这一点。     

Anforderungen an den konventionellen Kraftwerkspark – wieviel und welche Kraftwerkskapazit?t wird ben?tigt?

The electricity supply system will, particularly in Germany, significantly be determined by the use of renewable energy sources. A?decreasing energetic utilization along with an increasing flexibility demand lead to chancing requirements for the conventional plant fleet. The question arises to what extent conventional generation capacity is needed in the future and if??compared to today??additional technical requirements have to be fulfilled due to the increased flexibility demand. Furthermore it has to be discussed how a required capacity level can be achieved and if??and under which conditions??today??s market design is sufficient or if additional capacity mechanism are necessary. These questions are discussed in this article. The questions as to the required capacity level and the means to achieve it depend on the perspective, which is chosen with respect to security of supply. Choosing a European perspective, i.e. a common responsibility for an appropriate level of security of supply in Europe, additional capacity mechanism are not necessary. Choosing a national perspective, i.e. requiring that national demand can??theoretically??be covered by capacity available in the particular country, does not only significantly increase the necessary amount of generation capacity but also??due to the fact that the electricity market already today is organized on a European rather than a national basis??requires additional capacity mechanisms to cover capacity demand. With respect to the flexibility demand a concerted as well as coordinated acting of the different independent market players is necessary to cover a more volatile residual load. However, there is no additional demand for technical flexibility.