The energy potential of agricultural residues in Tanzania has so far not been evaluated and quantified sufficiently. Moreover, the scientific basis for estimations of the sustainable potential of wastes and residues is still very limited. This paper presents an attempt to evaluate the theoretical and technical potential of residues from the sisal sector in Tanzania with regards to energy recovery through anaerobic digestion. The characteristics and availability of sisal residues are defined and a set of sustainability indicators with particular focus on environmental and socio-economic criteria is applied. Our analysis shows that electricity generation with sisal residues can be sustainable and have positive effects on the sustainability of sisal production itself. All sisal residues combined have an annual maximum electricity potential of 102 GW h in 2009, corresponding to up to 18.6 MW of potential electric capacity installations. This estimated maximum potential is equivalent to about 3 % of the country's current power production. Utilizing these residues could contribute to meeting the growing electricity demand and offers an opportunity for decentralized electricity production in Tanzania.
Transponder-based Aircraft Detection Lighting Systems (ADLS) are increasingly used in wind turbines to limit beacon operation times, reduce light emissions, and increase wind energy acceptance. The systems use digital technologies such as receivers of digital transponder signals, LTE/5G, and other information and communication technology. The use of ADLS will be mandatory in Germany both for new and existing wind turbines with a height of >100 m from 2023 (onshore) and 2024 (offshore), so a nationwide rollout is expected to start during 2022. To fully realize the benefits while avoiding risks and bottlenecks, a thorough and holistic understanding of the efforts required and the impacts caused along the life cycle of an ADLS is essential. Therefore, this study presents the first multi-aspect holistic evaluation of an ADLS. A framework for evaluating digital applications in the energy sector, previously developed by the authors, is refined and applied. The framework is based on multi-criteria analysis (MCA), life cycle assessment (LCA), and expert interviews. On an aggregated level, the MCA results show an overall positive impact from all stakeholders’ perspectives. Most positive impacts are found in the society and politics category, while most negative impacts are of technical nature. The LCA of the ADLS reveals a slightly negative impact, but this impact is negligible when compared to the total life cycle impact of the wind turbines of which the ADLS is a part. Besides the aggregated evaluation, detailed information on potential implementation risks, bottlenecks, and levers for life cycle improvement are presented. In particular, the worldwide scarcity of the required semiconductors, in combination with the general lack of technicians in Germany, lead to the authors’ recommendation for a limited prolongation of the planned rollout period. This period should be used by decision-makers to ensure the availability of technical components and installation capacities. A pooling of ADLS installations in larger regions could improve plannability for manufacturers and installers. Furthermore, an ADLS implementation in other countries could be supported by an early holistic evaluation using the presented framework.
The development of digital technologies is accelerating, enabling increasingly profound changes in increasingly short time periods. The changes affect almost all areas of the economy as well as society. The energy sector has already seen some effects of digitalization, but more drastic changes are expected in the next decades. Besides the very positive impacts on costs, system stability, and environmental effects, potential obstacles and risks need to be addressed to ensure that advantages can be exploited while adverse effects are avoided. A good understanding of available and future digital applications from different stakeholders' perspectives is necessary. This study proposes a framework for the holistic evaluation of digital applications in the energy sector. The framework consists of a combination of well-established methods, namely the multi-criteria analysis (MCA), the life cycle assessment (LCA), and expert interviews. The objective is to create transparency on benefits, obstacles, and risks as a basis for societal and political discussions and to supply the necessary information for the sustainable development and implementation of digital applications. The novelty of the proposed framework is the specific combination of the three methods and its setup to enable sound applicability to the wide variety of digital applications in the energy sector. The framework is tested subsequently on the example of the German smart meter roll-out. The results reveal that, on the one hand, the smart meter roll-out clearly offers the potential to increase the system stability and decrease the carbon emission intensity of the energy system. Therefore, the overall evaluation from an environmental perspective is positive. However, on the other hand, close attention needs to be paid to the required implementation and operational effort, the IT (information technology) and data security, the added value for the user, the social acceptance, and the realization of energy savings. Therefore, the energy utility perspective in particular results in an overall negative evaluation. Several areas with a need for action are identified. Overall, the proposed framework proves to be suitable for the holistic evaluation of this digital application.
New options are needed to reduce the impact of motor vehicles on climate change and declining fossil fuel resources. Cars which are fueled by hydrogen could be a sustainable method of transportation if suitable technologies can be devised to produce hydrogen in an environmentally benign manner along with the provision of the necessary fueling infrastructure. This paper assesses size, space, and cost requirements of bioreactors as a decentralized option to supply hydrogen powered cars with biohydrogen produced from algae or cyanobacteria on a theoretical basis. Decentralized supply of biohydrogen could help to reduce the problems that hydrogen cars face regarding market penetration. A feasibility study for decentralized biohydrogen production is conducted, taking the quantity of hydrogen which is needed to fuel current hydrogen cars into account. While this technology is, in theory, feasible, sizes, and costs of such reactors are currently too high for widespread adoption. Thus, more R&D is needed to close the gap and to approach marketability.
Technologischer Wandel ist wichtig für die Umsetzung und den Erfolg der Energiewende, deswegen strebt die Bundesregierung mit ihrer Politik auch eine positive Innovationswirkung an. Doch welche Auswirkungen hat der politisch angestoßene Wandel des Energiesystems wirklich und welche Dynamiken werden durch ihn induziert? Eine aktuelle Studie untersucht die Sicht auf die Energiepolitik und Innovationsaktivitäten in der Energiewirtschaft und Energietechnologie-Branche. Sie zeigt die durch die Energiewende getriebenen Innovationsdynamiken, aber auch Schwierigkeiten und Herausforderungen für Politik und Unternehmen auf.
The study presents the results of an integrated assessment of carbon capture and storage (CCS) in the power plant sector in Germany, with special emphasis on the competition with renewable energy technologies. Assessment dimensions comprise technical, economic and environmental aspects, long-term scenario analysis, the role of stakeholders and public acceptance and regulatory issues. The results lead to the overall conclusion that there might not necessarily be a need to focus additionally on CCS in the power plant sector. Even in case of ambitious climate protection targets, current energy policy priorities (expansion of renewable energies and combined heat and power plants as well as enhanced energy productivity) result in a limited demand for CCS. In case that the large energy saving potential aimed for can only partly be implemented, the rising gap in CO2 reduction could only be closed by setting up a CCS-maximum strategy. In this case, up to 22% (41 GW) of the totally installed load in 2050 could be based on CCS. Assuming a more realistic scenario variant applying CCS to only 20 GW or lower would not be sufficient to reach the envisaged climate targets in the electricity sector. Furthermore, the growing public opposition against CO2 storage projects appears as a key barrier, supplemented by major uncertainties concerning the estimation of storage potentials, the long-term cost development as well as the environmental burdens which abound when applying a life-cycle approach. However, recently, alternative applications are being increasingly considered–that is the capture of CO2 at industrial point sources and biomass based energy production (electricity, heat and fuels) where assessment studies for exploring the potentials, limits and requirements for commercial use are missing so far. Globally, CCS at power plants might be an important climate protection technology: coal-consuming countries such as China and India are increasingly moving centre stage into the debate. Here, similar investigations on the development and the integration of both, CCS and renewable energies, into the individual energy system structures of such countries would be reasonable.
Obwohl viele der aktuellen Herausforderungen im Bereich der Energieversorgung eine internationale Dimension haben bzw. nur international gelöst werden können, ist die internationale Energiepolitik bis heute ein weitgehend ungesteuerter Politikbereich. Im letzten Jahrzehnt entwickelten sich zwar neue globale Kooperationsstrukturen und Initiativen, der Weg zu einer multilateralen, globalen Governance-Struktur, die zentrale Impulse für die gemeinsame Etablierung international geltender Normen und Regeln geben könnte, ist aber noch weit. Der Artikel führt in die aktuellen Entwicklungen ein und diskutiert die verbleibenden Herausforderungen.
Mit dem Kernenergieunfall im japanischen Fukushima im März 2011 ist die Diskussion über das Für und Wider der Nutzung der Kernenergie für die Stromerzeugung in Deutschland neu entbrannt. Die Frage nach den Auswirkungen eines beschleunigten Ausstiegs aus der Kernenergienutzung auf die Entwicklung der Strompreise in Deutschland bildete in den vergangenen Monaten einen Schwerpunkt der öffentlichen Diskussion. Allerdings halten nicht alle Aussagen, die hierzu veröffentlicht wurden, einer kritischen Analyse stand, was zum Teil auch an zugrunde liegenden politischen Motiven gelegen haben mag. Eine Untersuchung fundierter Studien und ausgewählter Stellungnahmen zeigt, dass sich die befürchteten kurzfristigen Preiseffekte in ü̈berschaubaren Grenzen halten werden.
Die Landesregierung in NRW hat am 14.4.2015 den in einem aufwändigen Stakeholderprozess erstellten Klimaschutzplan vorgestellt. Eines der Ziele war, die Klimaschutzpolitik als langfristige Strukturpolitik zu implementieren und entsprechende Prozesse in die Breite der Gesellschaft zu tragen. Weitere Bundesländer und der Bund selbst haben inzwischen ähnliche Prozesse eingeleitet. In zahlreichen anderen Ländern gibt es Beschlüsse, die in diese Richtung gehen. Eine Übersicht über den Prozess der Planerstellung in NRW und über den Stand der Diskussion in Deutschland verdeutlicht, wie Klimaschutzpläne durch partizipatorische Elemente in der Erstellungsphase mehr Akzeptanz erfahren können.
Using natural gas for fuel releases less carbon dioxide per unit of energy produced than burning oil or coal, but its production and transport are accompanied by emissions of methane, which is a much more potent greenhouse gas than carbon dioxide in the short term. This calls into question whether climate forcing could be reduced by switching from coal and oil to natural gas. We have made measurements in Russia along the world's largest gas-transport system and find that methane leakage is in the region of 1.4%, which is considerably less than expected and comparable to that from systems in the United States. Our calculations indicate that using natural gas in preference to other fossil fuels could be useful in the short term for mitigating climate change.