Techno-ökonomische Bewertung von Energie-Autarkie für die Energieversorgung von Einfamilienhäusern

Many consumers currently follow the idea of energy self-sufficiency and try to contribute to meet their energy needs in order to become independent and self-sufficient from the central power supply system. In order to achieve load-oriented energy self-sufficiency the provision of energy must cover the full energy demand at any time. Against this background, in this paper the costs and potentials of a load-oriented energy self-sufficiency of single-family homes are analysed. Thereby it is differentiated between electricity-, heat- and energy self-sufficiency. The modelling is carried out with the simulation environment ?Polysun Designer“ which allows a high temporal dynamic simulation of the annual energy demand and supply.The results show that, within the investigated supply variations, the highest levels of energy self-sufficiency can be achieved by an energy supply system completely based on electricity using a combination of PV; heat pump and battery storage. Depending on the building standard, a maximum of 45 (existing buildings) and 71?% (new buildings) of the building’s energy demand can be covered with renewable energy. The economic evaluation however has shown that under present conditions, none of the investigated supply variants can compete with conventional energy supply (public grid connection + gas condensing boiler).     

Und Aktion! – Konzeptualisierung der Rolle individuellen Akteurshandelns in sozio-technischen Transitionen am Beispiel der regionalen Energiewende im bayerischen Allgäu

The German “Energiewende” is one of the most ambitious societal transition projects in recent times. It causes fundamental political and economic changes in the energy system in Germany and the whole of Europe. These great societal and technological changes of the current energy regime are of particular interest for research on sustainability transitions. In this research strand, however, the role of individual agency for socio-technical transitions is hardly considered. What drives actors who decisively pushed the regional energy transition? Which strategies and types of action do they choose to foster the transition? How do individual strategies and actions depend on the socio-technical system environment and how does the socio-technical system environment react to the individual actions? To analyse these questions, we apply the Human-Environment Systems (HES) Framework (Scholz, 2011) for the first time to socio-technical systems. Based on an exemplary analysis of the regional energy transition in the Allgäu region in Germany, we propose an adaptation of the HES Framework for socio-technical systems. Finally, we reflect on how the adapted HES framework for socio-technical systems can contribute to a better understanding of individual agency in systemic transitions.     

Markt- und Systemintegration von erneuerbaren Energien im Rahmen der Systemtransformation – Ein Beitrag zur definitorischen Abgrenzung

The reconstruction of the electricity system is one of the main challenges of the German energy transition (Energiewende). The expansion of renewable electricity generation should enable the phase out of nuclear and fossil power generators in the long run. The Renewable Energy Sources Act (Erneuerbare Energien Gesetz) aims at increasing renewable generation up to a share of at least 80?% in gross electricity consumption by the year 2050. There are many possible ways to reach this target. Today, the characteristics of the future energy systems become apparent through the legal framework and long term energy scenarios.Economic, social and regulatory hurdles will need to be overcome to enable the transition of the electricity system. In this context, specific measures are evaluated with respect to their contribution on the system transformation, system integration and market integration. Up until now a consistent framework for evaluating political actions and scientific that should effectively support the energy political objectives is not present. The concepts of power system transformation, power system integration and market integration are differentiated and defined to close this gap. Based on this framework, a practical example is evaluated. The exact definitions will help to objectify the political and scientific debate. Furthermore, it contributes to develop regulatory and market mechanisms.     

Zur Akzeptanz von Stromspeichern in Unternehmen

The German Energy Transition challenges the German Energy System with the integration of renewable energy and its mainly fluctuating nature (especially wind and PV-energy). In order to balance energy demand and supply scholars critically discuss decentralized electric energy storages as an option to introduce more flexibility to the system. In an industrial setting electric energy storage solutions are especially of interest to implement load management, meaning a temporal deferral of load capacity, for peak-shaving activities and the possibility to achieve higher consumption rates of self-generated electricity. One question arises: What do companies think about the use of energy storage solutions in their companies as of today? This article offers an empirical starting point in looking further into detail concerning the overall attitude and the level of knowledge with regard to electrical energy storage solutions based on guided interviews with companies of the manufacturing and processing industry in Germany.     

Operating Strategies for Battery Storage Systems in Low-Voltage Grids to Limit the Feed-In Power of Solar Power Systems Using Fuzzy Control

Germany’s energy turnaround is leading to an increasing integration of photovoltaics (PVs) throughout its distribution grid. To ensure safe grid operation in times of high solar radiation, PV plants must either be throttled back to comply with the feed-in limitation or store a portion of their excess electricity in batteries. This paper presents a grid-optimized operating strategy for PV storage systems based on a Fuzzy Logic Controller that reduces peak feed-in and thus also PV curtailment losses. The Fuzzy Logic Controller uses data on PV power surplus and battery charge level as input variables. To obtain good results, the set of numerical parameters of the membership functions is enhanced by evolutionary programming.The energetic assessment shows that even small electrical storage capacities (<<5?kWh) reduce curtailment losses considerably when using the grid-optimized operating strategy. The economic assessment shows that, in 2016, investments in PV storage systems with large PV plants and small batteries have small (positive) Internal Rates of Return. The system efficiency of the battery storage has a small impact on the profitability of PV storage systems, whereas the cycle stability and the electricity purchase price have a large impact. Moreover, there is an economic benefit for plant operators to switch from the simple to the grid-optimized operating strategy. Solar forecast inaccuracies and variations in load and generation profiles have a negligible impact on the performance of the control algorithm.     

Germany’s Energy Supply

Germany has only very limited domestic energy resources. Seventy percent of primary energy needs must be covered by imports. The markets for energy are marked by a wide diversity and a large number of providers. The oil market has been intensely competitive for decades now. Lignite and hard coal are subjected to fierce substitution competition, especially with natural gas. The natural gas and electricity markets were fully liberalized in 1998. Consumers can freely choose from a vast number of suppliers. Since the beginning of this century, however, state interference particularly in the electricity market has increased. The expansion of renewables has been promoted since the year 2000 by feed-in priority and feed-in remunerations regulated by the state. The energy transition initiated in 2011 is characterized by ambitious energy and climate policy targets. Key pillars include the conversion of electricity generation from production on the basis of conventional energy sources to a system based mainly on renewable energies combined with stringent requirements designed to enhance energy efficiency and what are probably the most ambitious climate protection targets worldwide. As regards the expansion of renewables and the phase-out of nuclear energy, Germany is keeping to its target path. By contrast, there are no signs yet that the objectives formulated in terms of the lowering of primary energy consumption and the reduction in greenhouse gas emissions will be achieved.     

Ein Jahr danach: Erste empirische Ergebnisse der Ausschreibungen für Windenergie an Land gemäß EEG 2017

The sixth amendment of the German Renewable Energy Sources Act (Erneuerbare-Energien-Gesetzes [EEG]) came into force at January 1st, 2017. Especially regarding onshore wind energy, it includes fundamental changes. Having set raised market integration as well as market compatibility and cost-efficiency as the main three goals, market-based tendering shall be the instrument to reach them.Meanwhile, the first three calls have been completed. This enables the opportunity for a first evaluation of the tendering as a system to fund onshore wind energy in Germany and a comparison of the criticism which came along with the newest amendment. At first glance, several improvements can be found: Especially a—previously expected—forced competition on the market but also low bid and tender values show a massive potential of cost reduction. However, the analysis further shows that energy cooperatives are disproportionally privileged, which leads to a distortion of competition and the risk of a future non-continuous development. Additionally, the current system results in regional disparities, coming along with disadvantages especially for the southern states. 10 suggestions for improvement show possible answers concerning the main shortcomings.     

Eine soziologische Systemanalyse und sozio-ökonomisches Review der Soziotechnik Energiewende

The transition of the energy supply system in Germany from fossil-nuclear energy resources to renewable energies is a policy issue and defines a society technics. Society technics takes responsibility for an essential societal need and should be based on an agreement between all actors in all involved systems. According to a society-technics there are benefits for encouraging research, good governance for political support, public understanding of science (PUSH), and academic consultation for politics.Positive implementation will results in optimal coordination as all systems will function and all actors will work for synergy-effects. But a sociological system analyses works out many “dyssynergies”, handling the transition only as technological challenges and failing in underlying this transformation as a socio-technical system. Using renewable energies will not only change the technological system architecture but also modifying social systems and individual attitudes.     

Promotion of Electricity from Renewable Energy in Europe Post 2020—The Economic Benefits of Cooperation

The availability of renewable energies differs significantly across European regions. Consequently, European cooperation in the deployment of renewable energy potentially yields substantial efficiency gains. However, for achieving the 2020 renewable energy targets, most countries purely rely on domestic production. In this paper, we analyze the benefits of cooperation compared to continuing with national renewable energy support after 2020. We use an optimization model of the European electricity system and find that compared to a 2030 CO₂-only target (?40 % compared to 1990), electricity system costs increase by 5 to 7 % when a European-wide renewable energy target for electricity generation (of 55 %) is additionally implemented. However, these additional costs are 41 to 45 % lower than the additional costs which would arise if the renewable energy target was reached through national support schemes (without cooperation). Furthermore, the cost reduction achieved by cooperation is quite robust with regard to assumptions about interconnector extensions and investment cost developments of renewable energy technologies. In practice, however, administrative issues and questions concerning the fair sharing of costs and benefits between the Member States represent major obstacles that need to be tackled in order to reach renewable energy targets at the lowest costs possible.     

Modellgestützte Bewertung des Kraft-Wärme-Kopplungsgesetzes 2016 anhand ausgewählter Anwendungsfälle in Wohngebäuden

Cogeneration is a promising technology in the energy transition amongst other things in view of its energy efficiency and its broad applicability in the household, tertiary and industry sectors. For the promotion of cogeneration technologies, support schemes are in place in German energy policy. Amongst other things the Combined Heat and Power (CHP) Act serves as the main instrument for the promotion since 2002. In the new version of the CHP Act of 2016 the German Federal Government strives towards a more market-oriented design resulting in significant amendments featuring inter alia a highly case-dependent tariff design with modified levels and durations of remuneration. It is therefore the aim of the present study to assess these modifications with respect to technical, economic and ecological aspects in a model-based approach by means of selected use cases at different levels of spatial aggregation for residential buildings. Results point to an economic advantageousness for cases of the medium energy consumption level (streets and blocks of houses) under the new regime as well as the reversal of this attractiveness for objects of high consumption (neighbourhoods, districts). Particularly, CHP plants tend be dimensioned comparatively smaller with a greater number of full-load hours under the new regime. Furthermore, implications with regard to technical and ecological aspects are shown in this contribution.     

Das Umlaufvermögen von Verteilnetzbetreibern

How much current assets are needed to operate a distribution system in Germany? The German “Energiewende” requires tremendous amounts of investment in the distribution network over the next years. The return of invested capital is regulated by § 7 Strom/GasNEV (German network tariff regulations). Current assets are principally included in the regulatory asset base in order to determine the regulatory equity yield rate. The regulatory authorities and distribution system operators have different point of views regarding the proper amount of current assets needed for operating a distribution network. This debate seems quite significant when considering that the average ratio of current assets to total assets is 25%. On the other hand, one could argue that distribution system operators do not need current assets at all. In order to address the issue of the proper amount of current assets for distribution system operators, business specific processes (such as the “EEG process”) should be examined. Furthermore, the provision of current assets causes costs of capital, which reduces the shareholder value and makes the acquisition of capital more challenging. This paper analyses such interrelations between current assets and shareholder value in regulated markets. Moreover, the current regulatory practice of cutting current assets in the regulatory asset base to a standardized amount does not seem appropriate. Rather there is a need for a multi-level and item-by-item based valuation scheme: Is the item required for the business? Is the amount limited to the efficient minimum? Is the amount comparable to other businesses? Concerning this matter, this paper examines proper instruments, such as the cash flow statement. In addition, this paper benchmarks the current (liquidity) ratio of distribution system operators and non-regulated companies. Based on this benchmark, the current assets of distribution system operators appear comparatively efficient. The results point out a need of action regarding current regulatory practice.     

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.     

Status,Daten und Entwicklungen der globalen Energieversorgung

Global energy consumption is growing. The growth in energy consumption is now covered roughly equally by renewable energy resources and fossil energy resources. Nevertheless, crude oil, natural gas and coal continue to form the backbone of energy supplies. This means that the dependency of energy supplies on fossil energy resources will continue for the foreseeable future. In Germany as well, there is no end in sight of the country decreasing its high dependency on imports of fossil energy resources despite the high growth rate of renewables—and due in part to the decline in domestic production and the withdrawal from nuclear power generation. Crude oil, natural gas, hard coal and lignite with a share of around 80%, still make the largest contribution to the German and global primary energy consumption.All of the renewables together cover around 17% of global energy consumption. Despite the almost inexhaustible potential, making energy generation from renewable sources available at a large scale and commensurate with demand is still in its infancy. By way of contrast, very large reserves of fossil energy resources have already been developed for many years, and are being used in growing quantities. The global comparison of already produced and therefore consumed energy resources and the still existing reserves and resources, reveal that large non-depleted energy potential still exists in all regions around the world. Whilst the potential hardly appears to be touched in Austral-Asia, in the CIS and North America, only a small portion has been produced to date even in Europe. This wealth in resources is primarily attributable to the large deposits of coal found on all continents, which, unlike conventional crude oil and natural gas, are not restricted to a few special regions. Although the Middle East is an extremely important region for crude oil and natural gas, the minor coal reserves in the area mean that its overall potential is comparatively small.     

Suffizienzorientierte Geschäftsmodelle am Beispiel von Stromspeichern

Business models are essential tools for understanding and creating the logic of a company’s business including all relevant stakeholders’ activities. Despite the knowledge of the organic-systematic interdependencies from companies with other stakeholders, business models of the energy economy primarily aim to transfer their value propositions via revenue streams into economical value. This article provides solutions for theoretical and practical extensions of business models for energy storaging to ensure they are sustainable in the future. Sufficiency-oriented energy storage business models are described as a sustainable framework.     

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.     

Knowledge,Use and Effectiveness of Social Acceptance Measures for Wind Projects

Wind energy is one of the key technologies to become independent of fossil fuels. Implementation of wind energy on a local level, however, has sometimes proved to be challenging and dealing with local acceptance of onshore wind turbines has become troublesome for some projects. Communication and public involvement are seen as strategies to prevent or respond to local opposition. This paper analyses the views of a variety of experts in wind energy on this matter. It focuses on eliciting their experiences with public participation measures. Furthermore, the perceived effectiveness of the measures for the social acceptance of wind energy projects is analysed. To do so, this paper draws on an expert survey among 207 individuals across Europe linked to wind energy projects. The analysis shows that negative reactions to wind farms are reported more frequently than positive reactions. In nearly 40% of cases, projects experience negative consequences on project development due to a lack of social acceptance, ranging from delays to changes in project plans and even termination. The vast majority of wind project developers respond to this by carrying out public participation activity at least sometimes. However, a much lower share does this systematically and the level of activity is low in early project phases. With regard to the relationship between project activities and project success, there is some support for the assumption that early and systematic involvement of the public and stakeholders is likely to reduce negative reactions.     

Energiewende: Alles eine Frage der Partizipation? Governance-Herausforderungen zwischen Zentralität und Dezentralität

The interaction of centralised and decentralised elements is not only a challenge for the technical und functional implementation of the energy transition, but also for the political and social assignment of developing adequate governance strategies for future energy systems. While “participation” is of capital importance for all governance approaches mediating centralising and decentralising trends, it is far from clear, how participation is to be realized in order to promote energy transition and avoiding pitfalls and flaws of participative decision making processes. Against the backdrop of a multi-dimensional understanding of “participation” comprising procedural, factual, legitimatory and meta-reflective functions, the paper considers the tense relations of participation and efficiency, legitimacy and professionalized expertise, thereby identifying structural challenges for participation in democratic societies. Finally, some suggestions are made, how the governance of the energy transition can be shaped in the future.     

Behavioral and Attitudinal Customer Loyalty in the Power Sector

The emergence of smart grids changes the customer-utility relationship. To facilitate the transition towards a sustainable, reliable and economically viable energy system, utilities need to develop smart grid products and services that have strong customer acceptance and enable different customer segments to engage in energy efficiency. Thus, integrating customer feedback on innovative smart grid services early in the innovation process is of crucial importance. Further, energy providers need to increase customer loyalty and invest in relationship marketing in order to survive and be successful in a competitive market environment.This article presents the findings of a five-month field experiment that investigated the effectiveness of different reward programs in increasing customer loyalty and customer feedback provision in the energy sector. The results demonstrate that reward programs have a positive effect on behavioral (customer feedback provision) and attitudinal (e.?g. satisfaction with the energy provider) aspects of customer loyalty. The reward type matters, however. While monetary reward programs are effective in increasing customer feedback provision, only social reward programs can improve attitudinal aspects of customer loyalty. Energy providers should therefore consider tailoring the reward type to meet their program objectives when employing reward programs.     

Can Lignite Take a Back Seat?

Transmission grid extension is a central aspect of the future energy system transition in Germany. This stems from the diverging occurrence of renewable energy feed-in and consumption as well as the targeted nuclear and currently discussed carbon phase-outs. After realizing the retirement of the domestic nuclear energy fleet by 2022, a next policy objective could be the phase-out of domestic lignite generation. The German electricity grid was not designed to accommodate these emerging challenges. Hence, the following paper addresses the impact of decommissioning lignite power plants on the most cost-effective grid extensions by 2030. To determine the optimal transmission grid design, efficient methods for techno-economic analysis are required. The challenge of conducting an analysis of grid extensions involves lumpy investment decisions and the non-linear character of several restrictions in a real-data environment. The following paper introduces the application of the Benders Decomposition, dividing the problem into an extension and a dispatch problem to reduce the degree of computational complexity. The results show that lignite phase-out can significantly increase the number of grid extensions in Germany. All scenarios simulating a lignite phase-out by 2030 lead to higher overall system costs but lower CO\({}_{2}\) emissions.     

World Energy Council’s Global Energy Scenarios to 2060

Since 1970, global energy consumption has more than doubled. Conventional resources, in particular oil, gas and coal, had a dominant share in supply and covered most of the growth in demand in the past. Even in 2015, these fossil fuels still accounted for more than 80% of global primary energy consumption. The contribution of renewable energies to the total electricity generation was 23% in 2015, the same share as in 1970. Developments in the coming decades will differ substantially, however. Total energy consumption will rise at a much more moderate pace than in the past, e.?g. by up to one third by 2060. Electricity consumption will double during this period. But even this is a considerable slowdown in growth compared with the five-fold increase seen between 1970 and 2015. And, unlike in the past, the emerging rise in consumption will essentially be covered by renewable energy sources. This is true especially for the electricity sector. This comparison with developments in the past shows the extent of the global energy transformation that may be expected in future. These developments are reflected in three global scenarios, which were published by the World Energy Council in October 2016. The results of this flagship study World Energy Scenarios to 2060 are mirrored with the main findings of the IEA’s World Energy Outlook and the U.S. EIA’s International Energy Outlook. The most important challenge indicated by the results of the mentioned studies is: the transformation, which is expected in the covered scenarios is not sufficient, in order to achieve the target of limiting the global temperature increase to less than 2 degrees Celsius compared to pre-industrial levels that was agreed by the international community of states in Paris at the end of 2015. It will be highlighted, which strategies could meet the requirement cost-efficiently—a prerequisite for its success.