Zukünftige Energie- und Industriesysteme
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Biogas and bio-methane that are based on energy crops are renewable energy carriers and therefore potentially contribute to climate protection. However, significant greenhouse gas emissions resulting from agricultural production processes must be considered, mainly resulting from agricultural production processes, as fertilizer use, pesticide etc.
This paper provides an integrated life cycle assessment (LCA) of biogas (i.e. bio-methane that has been upgraded and injected into the natural gas grid), taking into account the processes of fermentation, upgrading and injection to the grid for two different types of biogas plants thus examining the current state of the art as well as new, large-scale plants, operated by industrial players. Not only technical and engineering aspects are taken into account here, but also the choice of feedstock which plays an important role as to the overall ecological evaluation of bio-methane.
The substrates evaluated in this paper - aside from maize - are rye, sorghum, whole-crop-silage from triticale and barley, and the innovative options of agricultural grass (Landsberger Gemenge, a mixture of hairy vetch (vicia villosa), crimson clover (trifolium incarnátum) and Italian ryegrass (lolium multiflorum)) as well as a combination of maize and sunflower.
CCS is discussed in a broad sense throughout Europe. In this paper a cautious, conservative estimate of CO2 storage capacity for Germany and its neighbouring countries where CO2 emissions from Germany could possibly be stored (Netherlands, France, Denmark, Norway, UK and Poland) is presented. Such a lower limit calculation is necessary for orientation purposes for potential investors and political decision-makers.
Conservative CO2 sequestration capacity in deep saline aquifers for Germany is derived by the volumetric approach where parameters such as efficiency factor, CO2 density, porosity of the geological formation are of interest. It is assumed that every geological system is closed and thus an efficiency factor of 0.1 per cent (based on maximum pressure increase and total compressibility) for saline aquifers is applied. The capacity of German depleted oil and gas fields is based on cumulative recovery data and a sweep efficiency of 75 per cent. The storage capacity in the other considered countries, adjacent to Germany, are based on a critical review and adjustment of the results of the European reports JOULE II, GESTCO and GeoCapacity.
The conservative capacities for all countries together amount to 49 Gt CO2, from which Norway and the UK provide 36 Gt, all offshore in the North Sea. Compared to the emissions from large point sources in these countries during 40 years (47.6 Gt of CO2), a virtual balance is achieved. This can only be reached, if a large scale CO2 pipeline system is installed to connect these countries, especially Germany, to the large sinks in the North Sea. If additional restrictions like source-sink matching, acceptance issues and injection rates constraints are taken into account, the available storage space gets increasingly scarce.
International consensus is growing that a transition towards a low carbon society (LCS) is needed over the next 40 years. The G8, the Major Economies Forum on Energy and Climate, as well as the Ad Hoc Working Group on Long-term Cooperative Action under the United Nations Framework Convention on Climate Change, have concluded that states should prepare their own Low-emission Plans or Low-emission Development Plans and such plans are in development in an increasing number of countries.
An analysis of recent long-term low emission scenarios for Germany shows that all scenarios rely heavily on a massive scale up of energy efficiency improvements based on past trends. However, in spite of the high potential that scenario developers assign to this strategy, huge uncertainty still exists in respect of where the efficiency potentials really lie, how and if they can be achieved and how much their successful implementation depends on more fundamental changes towards a more sustainable society (e.g. behavioural changes).
In order to come to a better understanding of this issue we specifically examine the potential for energy efficiency in relation to particular demand sectors. Our comparative analysis shows that despite general agreement about the high importance of energy efficiency (EE), the perception on where and how to achieve it differ between the analysed scenarios. It also shows that the close nexus between energy efficiency and non-technical behavioural aspects is still little understood. This leads us to the conclusion that in order to support energy policy decisions more research should be done on energy efficiency potential. A better understanding of its potential would help energy efficiency to fulfil its role in the transition towards a LCS.
Iran as an energy-rich country faces many challenges in optimal utilization of its vast resources. High population and economic growth, generous subsidies program, and poor resource management have contributed to rapidly growing energy consumption and high energy intensity for the past decades. The continuing trend of energy consumption will bring about new challenges as it will shrink oil exports revenues restraining economic activities and lowering standard of living. This study intends to tackle some of the important challenges in the energy sector and to explore alternative scenarios for utilization of energy resources in Iran for the period 2005-2030. We use techo-economic or end-use approach along with econometric methods to model energy demand in Iran for different types (fuel, natural gas, electricity, and renewable energy) in all sectors of the economy (household, industry, transport, power plants, and others) and forecast it under three scenarios: Business As Usual (BAU), Efficiency, and Renewable Energy.
This study is the first comprehensive study that models the Iranian energy demand using the data at different aggregation levels and a combination of methods to illuminate the future of energy demand under alternative scenarios. The results of the study have great policy implications as they indicate a huge potential for energy conservation and therefore additional revenues and emission reduction under the efficiency scenario compared with the base scenario. Specifically, the total final energy demand under the BAU scenario will grow on average by 2.6 percent per year reaching twice the level as that in 2005. In contrast, the total final energy demand in the Efficiency scenario will only grow by 0.4 percent on average per year. The average growth of energy demand under the combined Efficiency and Renewable Energy scenarios will be 0.2 percent per year. In the BAU scenario, energy intensity will be reduced by about 30 percent by 2030, but will still be above today's world average. In the Efficiency scenario, however, energy intensity will decline by about 60 percent by 2030 to a level lower than the world average today. The energy savings under the Efficiency and Renewable scenarios will generate significant additional revenues and will lead to 45 percent reduction in CO2-emissions by 2030 as compared to the BAU trends.