Eigenerzeugung und Selbstverbrauch von Strom – Stand,Potentiale und Trends

Due to falling costs of self-production, increasing end-user electricity prices as well as indirect state incentives, self-production and consumption of electricity have become more and more attractive for end-users across all economic sectors. Thus, opportunities to evade taxes, surcharges and grid charges have arisen under the current legal framework. The situation is complicated by unclear requirements for the utilisation of state incentives as well as the vague statistical coverage of self-consumption. Historically, the total amount of self-consumption rose by 26?% between 2008 and 2012 to 56.7 TWh. The estimation of economic potentials and trends shows that development could accelerate substantially to a point where a considerable amount of the consumption in all sectors could be covered by self-production. This development will be significantly determined by the future legal framework regarding taxation and surcharges for self-consumption. Besides the level of taxes and surcharges, the minimum limit for charging small generation units will be a key control variable. From an economical point of view, derogations lead to distorted competition between various technologies that causes inefficient production structures and distributional effects. Moreover, they create a self-reinforcing effect: The higher the self-consumption is, the lower the assessment base for apportionments and charges becomes, and the higher the cost burden for the remaining end-users will be. As a result, the incentives for self-consumption are enhanced and, once again, the increased self-consumption causes further economic inefficiencies.     

Quantifizierung und Systematisierung der technischen und verhaltensbedingten Stromeinsparpotenziale der deutschen Privathaushalte

Electricity consumption in German households accounts for more than 10 % of energy-related CO₂ emissions. In spite of substantial improvements in, for example, the efficiency of household appliances, there is still a considerable electricity savings potential to be tapped in this sector. The possible contribution that the German residential sector can make to climate protection is correspondingly large. This paper aims to structure and quantify electricity savings potentials which could be exploited in German households either through investment measures or changed user behaviour. The total theoretical potential which can be tapped through the purchase of efficient household appliances and the replacement of electrical heaters and hot water generators (i.e. by encouraging investment) amounts to approx. 90 TWh/a. This corresponds to more than 60 % of the current electricity demand of all German households. By means of changed user behaviour, approx. 30 TWh of electricity could be saved according to our calculations. These results presented in this article were reached within the scope of the TRANSPOSE interdisciplinary research project (http://www.uni-muenster.de/Transpose/, the complete analysis can be downloaded at http://www.uni-muenster.de/imperia/md/content/transpose/publikationen/buerger_working_paper_3.pdf). This project is funded within the framework of the ‘Social-ecological Research’ programme of the German Federal Ministry for Education and Research.     

Prognose der Day-Ahead Wind- und Photovoltaikstromerzeugung – Einflussgrößen und Zuverlässigkeit

In the future, the percentage of renewable energies in the electricity generation is expected to increase continuously. Especially weather-dependent wind and solar power plays a substantial role. These energy sources are partly characterized by a fluctuating and imprecisely predictable power generation. To cover the residual load and to balance the forecast errors a rising number of flexible producers and consumers will be needed in the future. This is necessary to ensure the high security of supply of the German electricity grid.Against this background, the objective of the following investigation is to analyse the day-ahead forecasting quality of the feed-in from wind and photovoltaic systems in the control areas of Germany’s transmission system operators and in the entire area of Germany for the years 2010 to 15. The aim of this analysis is to identify the crucial parameters that influence the forecast error. Subsequently, the share of the wind and photovoltaic power forecast which can be considered as reliably predictable for the following day is estimated. In addition, the increase in this reliable prediction through a higher level of detail in the assessment of the forecast error is quantified. Based on these results, the need of flexibilities through the weather-dependent electricity supply from wind and photovoltaic systems can be estimated, and the impact on the electricity system can be evaluated.     

Grosse Stadtwerke – theoretische und empirische Exploration eines besonderen Akteurs in der Energiewende Deutschlands und der Schweiz

Urban utility companies are key players in the Swiss and German energy sector. Due to the federalist and subsidiary governance structure of the two countries’ energy sector, they perform highly system relevant tasks, as e.?g. managing the distribution grids or ensuring the public services for “their city”. In the public and scientific discourse on the role of different actor groups in the energy transition, however, not much attention is paid to urban utility companies. This contribution aims at a theoretical and empirical exploration of these particular actors by analysing their characteristics, specific challenges and strategic answers in the context of the energy transition. For this purpose, the article derives analytical dimensions for the analysis of urban utility companies from scholarly literature on transition studies, network industries and public corporate governance and empirically analyses characteristics and the current situation of urban utility companies in Germany and Switzerland. Methodologically, this article is based on an explorative, qualitative study, which synthesises results from a literature analysis, a document analysis, 38 expert interviews in both countries (in 2017) and two expert workshops conducted in Switzerland (in 2018). The study shows, how the characteristics of urban utility companies can be explained based on public corporate governance and network industries literature. This also allows to identify and understand their particular challenges, as e.?g. the fields of tension among public and private interest in the firms and the multi-dimensional relationship of owner or the particularities of network industries. Finally, this article points out, that the role of urban utility companies in the Swiss and German energy transition is neither just “inhibitor” nor pure “innovator”, but can be labelled as “intelligent follower” and “engineer of the energy transition”.     

Marktkonzentration und Marktmachtanalyse für den deutschen Regelenergiemarkt

We analyze the German market for tertiary electricity reserves in 2008. The cost of tertiary reserves of about €200 million accounted for 15% of the total cost of system services. The aim of the paper is to analyze the market structure to reveal possible opportunities for the execution of market power. To do so, we apply various concentration measures for the total market, as well as for all submarkets (i.e., different time frames, positive and negative reserves). We analyze: market shares, Herfindahl-Hirschman-Index, Pivotal Supplier Index (PSI) and the Residual Supply Index (RSI). Based on all concentration indicators, we find that all submarkets are best characterized as tight oligopolies with a (competitive) fringe. The four largest companies always qualify as being jointly dominant according to German competition law. The role of the fringe firms is, however, not negligible, in particular not for positive reserves. Strongest indication for market power is found for negative reserves from 0–8 a.m. Our analysis highlights that relying on single concentration indicators (e.g., market shares) can be misleading. It is sensible and often necessary to consider the full set of indicators.     

Einfluss von HGÜ-Verbindungen auf Markt und Netz

Studies assume that the political subsidization of renewable energies throughout Europe will increase the amount of congestions in the European transmission grid. In current discussions HVDC reinforcement measures are seen as one means to provide further transmission capacities and to ensure a reliable operation of the system. In an effort to contribute to these discussions the publication evaluates the effect of various HVDC reinforcement measures on the grid and the market. The assessment of these reinforcement measures is based on a macroeconomic approach which considers three major cost terms. The first term represents the electricity generation costs. HVDC reinforcement measures influence this cost term as market zones with different generation costs can be coupled and overall generation costs thus might sink. The second cost term is orientated on the necessary redispatch effort to guarantee a secure and reliable operation of the grid. The third cost term represents the investment costs of the HVDC reinforcement measures. The sum of all these cost terms is regarded as a means to compare different reinforcement measures. The study shows that the effect of all examined reinforcement measures on the transmission grid is comparable. Structural congestions in the grid which exist already without any HVDC reinforcement are not influenced significantly by the examined HVDC links. Of all considered reinforcement measures a link from Germany to Norway exhibits the highest influence on the market. This link also offers the highest benefit regarding market and grid as a whole.     

W?rmed?mmungs-Strategien im Haushaltssektor und ihr Beitrag zu Materialeffizienz und Emissionsminderung – eine Langfristanalyse bis zum Jahr 2050

An often controversial question is whether a massive insulation of houses in the overall balance does not cause more resource consumption and emissions than it saves in the end. To investigate this question, for the first time a trade-off analysis has been performed. For this, a bottom-up impact analysis model was developed, whose core forms an emissions- and energy model for the household sector which is coupled with a life cycle assessment tool. Both models provide the framework for energy scenarios to 2050, claiming for each decade refurbishment rates and energy mixes. Thus, ??pure?? energy scenarios can be extended by resource policy analyses and the effects of various insulation strategies might be determined. The central result of modeling is that additional costs are compensated for insulating (extruded polystyrene foam XPS and cellulose were examined) both resource- and emission-side in almost all environmental impact categories with significant savings in building heating. Essentially, there are no trade-offs identified, and the percentage contribution of the insulating materials on the environmental impact indicators is low. In contrast, the choice of foaming agent in the foamed XPS insulation is relevant: Compared with the XPS used in Germany, which is largely CO₂ foamed insulation, one which has a high proportion of HFCs, leads to a high trade-off regarding the impact category ??stratospheric ozone depletion?? and leads to a noticeable, but not significant effect on the global warming potential. A sensitivity analysis with the alternative cellulose insulation material shows that the already low shares of the insulation continue to decrease with regard to the environmental impact indicators. However, with regard to the material intensity, XPS and cellulose insulation are associated with similar effects. In summary, it can be stated that for both insulation materials ambitious strategies??with regard to all factors analysed in the study??can significantly contribute to material efficiency as well as to emissions reduction targets.     

Europäische Klimapolitik: Zwischen Anspruch und Wirklichkeit

In order to restrict the risks of anthropogenic climate change to a ?tolerable“ extent, the fourth assessment report of the United Nations’ International Panel on Climate Change calls for a trend reversal towards globally decreasing greenhouse gas emissions within the next two decades which ultimately must lead to a reduction of carbon dioxide emissions until the mid of the century by 50 percent as compared to 2000 emission levels. The European Union claims a lead of a role in climate policy with the objective to push forward international negotiations on far-reaching emission reduction commitments with other important industrialized and developing regions. The EU’s credibility as a leading force will hinge crucially on how successfully it can fulfill its emission reduction obligations under the Kyoto Protocol by means of market-based environmental policy, in particular the exemplary operation of the EU emission trading system. Against this background, the following article provides a critical assessment of the EU’s climate policy.     

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.     

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.     

Verlustwärme von Offshore-Gleichstrom-Seekabelsystemen – Entstehung und Übertragung

In Germany heat dissipation of subsea cables for power transmission from offshore wind farms into the sea floor is regulated. The precautionary value to be adhered to is a maximum temperature increase of 2?K in 20 to 30?cm sea bed depth. Such a temperature increase is defined by a number of influencing factors and boundary conditions and is extremely difficult to physically measure. Thus the purpose of this paper is to simulate the heat generation of DC submarine cables and the dissipation into the surrounding sea floor using the Finite Element Method (FEM). Herewith crucial parameters and influencing factors can be identified. The results show that the strongest influencing factors on the sediment temperature in 20 to 30?cm sea floor depth are the average load or longer-term preload of the cable, the burial depth and the thermal resistance of the sediment. Overall, during standard operation of wind farms and the corresponding cable systems the 2?K limit is adhered to safely. In general, this also applies to special wind and load situations.     

Gleichzeitigkeit als Leistungsgröße: Inter- und Intra-Klassen-Leistung volatiler EE-Einspeiser

The energy transition focuses on the expansion and enhancement of distribution grids and the integration of decentralized renewable generation plants. The integration of decentralized plants presents a major challenge for distribution system operators in particular. The planning and dimensioning of energy grids requires knowledge of all integrated generating units and power consumers, as well as their power ratings. Furthermore, knowledge about the diversity of renewable power plant types enables distribution system operators and scientists to selectively or cumulatively assess the maximum feed-in capacity. This is particularly important for the assessment of case studies or border scenarios. The purpose of this article is the evaluation of the maximum simultaneous feed-in power of PV and wind power plants. Furthermore, the ratio of the installed power to the maximum power generated by renewable power plants is also investigated. The diversity factor describes the ratio of the sum of all individual load’s maximum powers to the number of loads. This simultaneity can also be adapted to renewable power plants. However, it is differentiated here between simultaneous power within one renewable power plant type (intra-class performance) and simultaneous power of different renewable power plant types (inter-class performance). In cooperation with one of the largest national distribution network operator, regression lines are approximated by statistical analyzes, in order to determinate the diversity of the Central German area.     

Investitionsanreize unter RPI-X-Regulierung und die angemessene Höhe von Kostendurchreichungen

In the classic view, the fundamental decision between a rate-of-return and price-cap regime depends upon the aim of regulatory action: a rate-of-return is considered to more likely induce infrastructure investment while a price-cap regime is expected to increase managerial effort in reducing costs. While an asset-based regulation may lead to the unwanted Averch-Johnson effect, efficiency-oriented regulation such as RPI-X may decrease the company’s incentive to invest. To avoid this behaviour, RPI-X-regimes do often exempt certain costs from regulation, e.g. by allowing for pass-throughs for capital expenditures. Starting with the finding that efficiency-based regulation may lead to postponement or abandonment of investment projects in a real options based model, a fair rate of capital cost pass through is derived to mitigate the negative effects on investment projects. This ‘regulation-adjusted’ cost-pass-through depends on the regulatory X the regulator imposes on the regulated industry. Given the valuation of the investment project and the efficiency-value, a cost-pass-through can be calculated which is less or equal than the risk free interest rate as long as the pass-through itself is risk-free.     

Effizientere Ressourcenausnutzung geothermischer Anlagen – Technische Möglichkeiten und deren Bewertung

The geological conditions in Germany allow maximum temperatures between 160 to 170°C free well head taking techno-economic constraint into consideration. This makes an electricity production for purely technical reasons possible, but only with low efficiencies due to physical constraints. That’s why it assault big amounts of waste heat. For example, the existing geothermal power plants in Germany provide in average 18% of electricity and 82% of heat. This heat is use so far only to a very small degree. Even is a district heating system is operated to supply private households, this heat is used with less than 2.500 h per year. That’s why the still hot thermal water is press back into the underground without any further utilization. For these reasons to achieve a technical and economic optimization it should be the aim to find different reasonable options to use this waste heat. One possibility is the coupling with a drying process at the location of the geothermal plant. Such options will be analyzed from a technical and economic point of view and some conclusions will be drawn.     

Regulierung, Effizienz und das Anreizdilemma bei Investitionen in intelligente Netze

In this paper, we survey from a theoretical point of view to what extend cost-based and incentive-based regulatory regimes stimulate investments. For the purpose of this analysis, we furthermore differentiate by different efficiency measures, i.e. allocative efficiency, productive efficiency and dynamic efficiency and analyse to what extend each efficiency measure is stimulated by the regulatory regime. Eventually, we analyse to what extend regulatory incentives for network innovation in a smart grid context exist and to what extend different forms of regulation stimulate dynamic efficiency.     

Dynamische Berechnung der Stromgestehungskosten von Energiespeichern für die Energiesystemmodellierung und -einsatzplanung

Due to the transition in energy supply from fossil to renewable energy sources, energy storage systems are getting more and more important for the security of power supply. Therefore also the modeling of those storage systems in energy system modeling needs to be further discussed. This paper focuses on the levelized costs of energy storage. In the beginning, the existing approaches of calculating those costs are analyzed in a literature review. It will be shown that all of the approaches calculate the levelized costs on the basis of the energy storages’ lifetime. For the usage in energy system modeling it is mandatory that the calculation can be done for variable and shorter time periods. Therefore this work’s approach calculates the costs based on the time of operation in any period chosen. Additionally, the model can be used for any type of storage system. After introducing the mathematical model, the levelized costs of energy storage will be calculated to illustrate the models properties and then verified with reference load profiles for five different energy storage types. Following this, particular input parameters are varied and sensitivities are pointed out. Most of the programs for power plant dispatch calculations use linear or mixed integer linear programing algorithms. As the calculation of levelized costs of electricity is non-linear, most programs use fixed values during the whole time of simulation. In this article the integration of the presented approach into a linear optimization program via recursive and shifted calculation is elaborated. Results are presented and discussed.     

Bedeutung von CO2-Transport- und Speicheroptionen im europäischen Energiesystem

Aiming the stabilisation of the CO₂ concentration in the atmosphere at 450 ppm, a strong climate policy in the EU-27 will be required. Carbon Capture and Storage (CCS) and the building up of a CO₂ pipeline system will be one option to avoid climate change. The analysis of the potential CO₂ storage options in Europe shows a huge potential in the North Sea and their neighbouring countries and only less potentials in the southern European countries. A scenario analysis using the European energy system model TIMES PanEU shows that the installation of CO₂ transport pipelines for cross boarder exchange of CO₂ from power plants located next to the boarder could be one possible infrastructure solution. This solution is a cost efficient option which will be used mainly by the North Sea neighbouring countries (Germany, UK, the Netherlands, Denmark) and Poland. A central pipeline grid in the North Sea for the usage of huge storage options like the Utsira formation will be important in the future for countries with limited CO₂ storage capacities (like Belgium or the Netherlands). If cheap storage options like onshore Aquifers are not available, the design of central CO₂ pipeline grids has a strong impact on the power plant structure, the electricity and CO₂ certificate price. Based on a limited availability of onshore CO₂ storages the electricity price will increase by up to 16 € 2007/MWh and the CO₂-certificate price will rise by additional 35 € 2007/t CO₂ in 2050.     

Vergleichende Analyse der technisch-wirtschaftlichen Bedingungen von PV-Anlagen Mit Süd- und Ost-West-Ausrichtung

PV power plants with east-west-orientation have a lower energy production per installed kW_p due to their orientation than those facing to south. Thus they need a reduction of costs to compensate the lack of energy production and to have the same cost effectiveness as PV plants with south-orientation. This paper tries to show, how and if PV plants with east-west-orientation can be more profitable than PV plants with south-orientation. Therefore, the energy production was simulated for PV plants with an orientation to east-west and to south with different inclinations in a place with high irradiation (Freiburg) and a place with low irradiation (Hamburg). A calculation of profitability was made for each PV plant including energy production as well as ascertained costs. This are the main outcomes:

The profitability of PV plants with east-west-orientation is not better than the profitability of PV plants with south-orientation.

The profitability of PV plants with east-west-orientation is better than the one of PV plants with south-orientation when the costs of mounting systems are much lower for east-west mounting-systems than for mounting-systems with south-orientation and the costs of grid-connection and rent are high too.

The profitability of PV plants with east-west-orientation is higher in regions with low irradiation.

     

Klimawandel: Wahrnehmung und Einschätzungen der deutschen Haushalte im Herbst 2012

This article presents results that are obtained from a survey among private households in Germany, which took place in the fall of 2012. A key result is that in comparison with a range of other global challenges, respondents are less concerned with fighting climate change, a remarkable outcome given that the share of climate change skeptics in the survey is likely to be lower than in the population owing to selfselection problems. This article addresses such self-selection problems, as well as other shortcomings of surveys, and provides for a discussion on how to cope with them.     

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.