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[en] The objectives of this paper are to analyze the technical potentials and the respective costs of energy production from biomass in the Federal Republic of Germany. Both benefits and costs of residual products are investigated. The energy potential is approximately 310 PJ a-1, or about 3.3% of the final energy demand in Germany in 1991. The possibilities of producing solid energy carriers and liquid fuels on agricultural land are investigated. Conclusions are drawn on the possibilities and restrictions of energy production from biomass in Germany's energy system. (author)
[en] A number of plants for the utilisation of deep geothermal energy have been completed in Germany and other parts of the world in the course of the past year. In Germany four cogeneration plants with an total electrical capacity of 12 MW were in operation in 2012, producing a total of around 25 GWh of electrical energy and 0.32 PJ of thermal energy in that year. Furthermore, Germany's national fleet of geothermal heating plants had an overall thermal output capacity of 200 MW and a thermal yield of 1.2 PJ (330 GWh) in 2012. This amounts to savings of 107,000 tons of CO2 equivalent. Total electricity and heat production from geothermal energy worldwide showed continued growth through 2012. The total electrical capacity installed rose by almost 3% to 11.3 GW. Between them the world's geothermal power plants in existence at the end of 2012 had fed around 72 TWh of electrical energy into the grids in the course of the year. In addition these plants totalled an installed thermal capacity of approximately 15.4 GW, producing some 217 PJ (60 TWh) of heat. Many other activities towards making greater use of thermal energy from the deep underground were observed both in Germany and around the globe in 2012. In view of these developments it appears probable that the production of heat and/or electricity from geothermal energy will continue to grow in the years to come and that this option will gain significance in the realms of economic and environmental policy at both the national and international level.
[en] Biomass is seen as a very promising option for fulfilling the environmental goals defined by the European Commission as well as various national governments. The goal of this paper is to analyse the possibilities for energy provision from biomass in general and from solid biofuels in particular. The potentials of solid biofuels as well as their current use is analysed and discussed in the context of the overall energy system. The result of this analysis shows that there are still unused potentials, which can contribute significantly to cover the energy demand within the EU-15. The most important markets for solid biofuels are analysed in detail; markets for solid biofuels with low, medium, and large variations of fuel properties. This investigation shows that biofuels with essentially uniform fuel properties have shown the most impressive market developments in recent years. The main prerequisite to achieve this significant growth in market volume has been standardisation of the fuel properties. Therefore biofuel standardisation is seen as a major key issue to develop the markets. (author)
[en] Although the need to decarbonise our global economy and thus in particular the supply of energy to limit the global temperature increase is internationally undisputed the German politics in 2014 has significantly contributed less compared to previous years in order to attain this objective. The expansion of renewable energies in the electricity sector has decelerated significantly; and in the heating and mobility area no new impulses were set in relation to renewable energies. In addition, a dramatic fallen oil price makes it difficult to increase the use of renewable energy supply. Based on these deteriorated framework conditions compared to conditions of the previous years, the developments in Germany of 2014 are shown in the electricity, heat and transport sector in the field of renewable energy. For this purpose - in addition to a discussion of the current energy economic framework - for each option to use renewable energies the state and looming trends are analyzed.
[de]Obwohl die Notwendigkeit zur Dekarbonisierung unserer globalen Wirtschaft und damit insbesondere der Energiebereitstellung zur Begrenzung des globalen Temperaturanstiegs international unstrittig ist, hat die deutsche Politik im Jahr 2014 im Vergleich zu den Vorjahren deutlich weniger zur Erreichung dieses Zieles beigetragen. Der Ausbau der Stromerzeugung aus erneuerbaren Energien im Stromsektor wurde deutlich verlangsamt; und im Waerme- und Mobilitaetsbereich wurden keine neuen Impulse in Bezug auf regenerative Energien gesetzt. Zusaetzlich erschwert ein drastisch gefallener Rohoelpreis die verstaerkte Nutzung des erneuerbaren Energieangebots. Ausgehend von diesen im Vergleich zu den Vorjahren verschlechterten Rahmenbedingungen werden nachfolgend die Entwicklungen in Deutschland des Jahres 2014 im Strom-, Waerme- und Transportsektor fuer den Bereich der erneuerbaren Energien aufgezeigt. Dazu werden - neben einer Diskussion des derzeitigen energiewirtschaftlichen Rahmens - fuer die einzelnen Optionen zur Nutzung erneuerbarer Energien der Stand und die sich abzeichnenden Entwicklungen analysiert.
[en] Rice straw and rice husks occur in large quantities as side streams of the world wide rice production. These side streams can be used as a renewable source of energy via the biochemical as well as the thermochemical conversion route. Exemplarily for samples from various South-East Asian countries, the most important characterizing figures are measured analytically. Then, the two conversion routes—based on a thermochemical as well as on a biochemical conversion—are discussed in detail. Based on such technological solutions as well as the measured data, nine case studies for each conversion system are defined and assessed related to the levelized costs of electricity (LCOEl) and energy (LCOEn). Additionally, the specific substrate demands (SSDs) and specific land demands (SLDs) are calculated indicating the mass and area efficiency of chosen substrates and systems.
[en] Due to recent developments in energy politics renewable energies get more and more importance in Germany. This is especially true for geothermal energy representing a promising option for the environmentally sound and secure generation of heat and electricity. But there are a lot of very emotional discussions due to radioactive residues and wastes produced by a geothermal plant. Thus this paper compares radioactivity resulting from geothermal energy with radioactivity coming from other natural sources. In doing so it becomes obvious that naturally radioactive sources exist in all parts of the ecosphere (i.e. air, water, soil). The paper shows also that the specific activities of radioactive elements from geothermal energy in form of residues and waste emerge from radioactive decay of nuclides and that their radiation is not higher than the radiation of other naturally occurring radioactive elements. (orig.)
[en] Highlights: • The shift from 1st generation to 2nd generation bioethanol from straw is assessed. • Resulting GHG emissions are evaluated in the context of European legislation. • Emissions might increase if 2nd generation ethanol replaces 1st generation ethanol. • A detailed analysis of land-use change mechanisms confirms results. • Consequently, proposed EU legislation might provoke unintended consequences. - Abstract: Until today, first generation (1G) biofuels dominate the market for alternative fuels. The European Commission decided to cap 1G biofuels and promote second generation (2G) biofuels with the intention to reduce greenhouse gas (GHG) emissions, to limit the competition of food, feed and biofuels, as well as to improve societal approval. The assessment of consequences entailed to a shift from 1G to 2G biofuels is required to judge whether such a shift is advisable or not. According to the renewable energy directive (RED), GHG savings, need to be determined for all biofuels. By the end of 2020, fuel blends need to achieve a GHG reduction of 6%. Thus, GHG savings will determine the quantity of biofuel to be blended with fossil fuels and thereby eventually define the demand for biofuels. In this paper, the consequences of a shift from a 1G to a 2G biofuel is assessed by the example of bioethanol from wheat grains and straw. In total, three concepts of 2G ethanol production from wheat straw are considered: fermentation of C6-sugars with (1) co-production of feed, (2) coupled with biogas production and (3) co-fermentation of C5- and C6-sugars with co-production of feed. To determine the effect of the introduction of 2G ethanol, GHG savings according to RED are calculated first, and, in a second step, consequences of the shift from 1G to 2G ethanol are assessed by accounting for substitution mechanisms and emissions from direct and indirect land-use change (LUC). GHG savings of these 2G concepts according to RED methodology range from 103 to 105%. The shift from 1G ethanol to these 2G concepts is assessed by two scenarios: (1) additional production of 2G ethanol and (2) the replacement of 1G ethanol by 2G ethanol. Results indicate that GHG emissions decrease in scenario 1 if all surplus ethanol replaces fossil fuels. Under the given assumptions, the reduction in emissions ranges from 9.0 to 12.1 kg CO2-eq./GJ ethanol-gasoline blend. If 1G ethanol is replaced by 2G ethanol, GHG emission increase in a range from 7.5 to 16.5 kg CO2-eq./GJ fuel blend. This is mainly due to the provision of feed that needs to be supplied as a consequence of the shift in production: 1G ethanol production provides a high protein feed that needs to be provided by other means. Hence, the main driver for an increase in emissions is the provision of soybean meal and entailed emissions from LUC. A sensitivity analysis shows that these results are robust regarding input parameters and LUC assumptions. These findings point out that it is of utmost importance to assess changes induced by the introduction of novel fuels rather than assessing them isolated from market conditions. Based on these findings, it can be concluded that current and proposed legislation might trigger effects opposed to those intended.
[en] Highlights: ► Ethanol production from sugar beet and wheat is investigated. ► Instead of feed production from residues by-products are used for energy production. ► Ethanol from sugar beet with biogas co-production shows lowest GHG emissions. ► For wheat pathways bran and gluten separation generates lowest GHG emissions. ► An allocation method is recommended involving co-produced fertilizer. -- Abstract: In state of the art ethanol production, by-products like vinasse from sugar beet or distiller’s dried grains with solubles (DDGSs) from wheat grains are usually used as animal feed. The drying process consumes a significant amount of energy that could be reduced by producing other valuable materials or energy carriers from these by-products. Besides resulting higher overall conversion rates and improved process efficiencies, by-products, which can be extracted or are automatically created during the various conversion steps, should be used to reduce environmental impacts as well. In this analysis, advanced pathways for the recovery and use of by-products from bio-chemical ethanol production like gluten separation from wheat starch, biogas production from stillage or vinasse and combustion of bran for electricity generation are analyzed with regard to their contribution to the greenhouse effect. Therefore, different methodological approaches are applied and compared. The analysis shows among others that ethanol from sugar beet generates less greenhouse gases (GHGs) compared to the ethanol production from wheat. The biogas production from residues and especially the use of bran for heat and electricity generation shows significant GHG reduction compared to the state of the art application. However, the methodological approach for the treatment of by-products highly influences the results. For the reproducibility of the results an energy equivalent allocation method involving the specific application of the respective co-product is recommended.
[en] The key driver for the expansion of regenerative energies was and continues to be climate protection, with the still valid goal of keeping the maximum anthropogenic global temperature increase below 2.0 C on average. However, the implementation of this goal is losing importance in many places; this is evident both in the recently concluded coalition agreement between the CDU, CSU and SPD and, for example, in the environmental policy of the US administration. In addition, the relatively low price of fossil energy offers no real incentive to accelerate the transformation of the energy system. That is why in 2017, only in the electricity sector, there was a noticeable expansion of renewable energies in Germany; and above all by the wind energy and - much more limited - by the photovoltaic. On the other hand, the use of renewable heat has decreased slightly, and in the mobility sector, only modest expansion in electric mobility took place in 2017. Based on this, the status and emerging developments in Germany in the year 2017 in the electricity, heating and transport sector for the individual options for the use of renewable energies will be shown and discussed.
[de]Der zentrale Treiber fuer den Ausbau der regenerativen Energien war und ist weiterhin der Klimaschutz mit nach wie vor gueltigem Ziel, den maximalen anthropogenen globalen Temperaturanstieg im Mittel unter 2,0 C zu halten. Die Umsetzung dieses Ziels verliert aber gerade vielerorts an Bedeutung; dies wird sowohl im gerade geschlossenen Koalitionsvertrag von CDU, CSU und SPD und beispielsweise auch in der Umweltpolitik der US-Administration deutlich. Zudem bietet der relativ niedrige fossile Energiepreis keine wirklichen Anreize fuer einen beschleunigten Umbau des Energiesystems. Deshalb kam es in Deutschland 2017 lediglich im Strombereich zu einem merklichen Ausbau der erneuerbaren Energien; und hier vor allem durch die Windenergie und - deutlich eingeschraenkter - durch die Photovoltaik. Dahingegen hat die Nutzung erneuerbarer Waerme leicht abgenommen, und im Mobilitaetssektor erfolgte 2017 lediglich bei der Elektro-Mobilitaet ein leichter Ausbau. Ausgehend davon werden nachfolgend der Stand und die sich abzeichnenden Entwicklungen in Deutschland im Jahr 2017 im Strom-, Waerme- und Transportsektor fuer die einzelnen Optionen zur Nutzung erneuerbarer Energien aufgezeigt und diskutiert.
[en] Geothermal binary power plants that use low-temperature heat sources have gained increasing interest in the recent years due to political efforts to reduce greenhouse gas emissions and the consumption of finite energy resources. The construction of such plants requires large amounts of energy and material. Hence, the question arises if geothermal binary power plants are also environmentally promising from a cradle-to-grave point of view. In this context, a comprehensive Life Cycle Analysis (LCA) on geothermal power production from EGS (enhanced geothermal systems) low-temperature reservoirs is performed. The results of the analysis show that the environmental impacts are very much influenced by the geological conditions that can be obtained at a specific site. At sites with (above-) average geological conditions, geothermal binary power generation can significantly contribute to more sustainable power supply. At sites with less favorable conditions, only certain plant designs can make up for the energy and material input to lock up the geothermal reservoir by the provided energy. The main aspects of environmentally sound plants are enhancement of the reservoir productivity, reliable design of the deep wells and an efficient utilization of the geothermal fluid for net power and district heat production.