Zukünftige Energie- und Industriesysteme
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The present brief analysis provides an overview about costs and benefits of the promotion of renewable energies in the framework of the EEG. We describe the development of the EEG apportionment in recent years, and its possible development in coming years. Furthermore, the analysis examines the merits of some of the most commonly expressed points of criticism against the EEG. Finally, we examine the extent to which the calculations regarding the costs of the expansion of photovoltaics, which are often raised in the media, are correct, and how they are to be interpreted.
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 (GHG) emissions resulting from agricultural production processes must be considered. Among those, the production and use of fertilizer, and the resulting leaching of nitrous oxide (N2O), are crucial factors. This article 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. The analysis is based on different feedstocks from crop rotation systems for different locations in Germany. A special focus is on the sensitivity of assumptions of nitrous oxide emissions to overall GHG emissions. Much research exists on the measurement or modeling of the actual N2O emissions that result from farming processes. Since there is as yet no precise regional data, most analyses use tier-1 data from the IPCC national GHG inventories as a default. The present article coincides with recent research in indicating that this data varies at the regional level. However, it is not the scope of the article to evaluate the quality of existing data for N2O emissions, but to show the effects of different assumptions on the LCA of GHGs from bio-methane. Thus, a link between the provision of emission data and the practical implementation of biogas technology is provided. The main result is that the supply chain of substrates from agricultural processes appears to contribute the most to the GHG emissions of bio-methane. The "worst case" scenario where 5% of the nitrogen fertilizer used is emitted in form of N2O shows that the GHG mitigation potential of bio-methane versus natural gas is very small, so there is not much margin for error in the plant technology.
Energy used in buildings is responsible for more than 40% of energy consumption and greenhouse gas (GHG) emissions of the EU and their share in cost-efficient GHG mitigation potentials is estimated to be even higher. In spite of its huge savings potential of up to 80%, achievements are very slow in the building sector and much stronger political action seems to be needed. One important step in this direction has been the recast of the Energy Performance of Buildings Directive (EPBD) in autumn 2009. However, strong national implementation including powerful packages of flanking measures seems to be crucial to really make significant progress in this important field. In order to directly improve political action, we provide a differentiated country-by-country bottom up simulation of residential buildings for the whole EU, Norway, Iceland, Croatia and Liechtenstein. The analysis provides a database of the building stock by construction periods, building types, as well as typical building sizes. It includes a simulation of the thermal quality and costs of the components of the building shell for new buildings as well as the refurbishment of the existing building stock. Based on this differentiated analysis, we show in detail what would be needed to accelerate energy savings in the building sector and provide a more precise estimate of the potentials to be targeted by particular policies. We demonstrate, e.g. that the potential of building codes set via the EPBD would be located mainly in those countries that already have quite stringent codes in place. We show as well the high relevance of accelerating refurbishments and re-investment cycles of buildings. By providing a clear estimate of the full costs related to such a strategy, we highlight a major obstacle to accelerated energy-efficient building renovation and construction.
Securing universal access to electricity by using renewable energy sources is technically feasible. A broad range of technological options, which can meet almost any requirements, are available. Solutions can comprise the connection of users to large distribution networks (on-grid solutions) or the application of power supply systems that can operate autonomously (off-grid and mini-grid solutions). This brochure concentrates on the latter solutions; technologies for large-scale distribution are not covered.