Bert Droste-Franke

Balancing Renewable Electricity. Energy Storage, Demand Side Management and Network Extension from an Interdisciplinary Perspective

Current images of our future energy system include the assumption that a high proportion of renewable energies will be used. Relevant scenarios assume that by 2050 anywhere from 80 to even 100 percent of our electricity will be generated from renewable energy sources. In addition to power generating systems, the necessary ingredients for a working system with a high proportion of renewable energy sources include climate-friendly technologies for balancing the supply and demand of electricity. This is of particular importance with regard to wind turbines and photovoltaic systems whose supply often plummets due to adverse weather conditions. The Europaische Akademie has now published an interdisciplinary study entitled “Balancing Renewable Electricity. Energy Storage, Demand Side Management and Network Extension from an Interdisciplinary Perspective”. It provides a comprehensive overview of the use of energy storage systems, demand side management and extended networks for balancing supply and demand within systems which have a high proportion of renewable energy sources. Based on the results of a threeyear research project at the Europaische Akademie, researchers from the fields of power engineering, technology assessment, political science, economics and law are making recommendations in a joint effort for the development and implementation of climate-friendly strategies for balancing supply and demand within the electricity system. It will prove challenging to provide power according to different time scales – since it must be available within fractions of a second and continue to be available for several hours or days. Because of the challenge this task represents, the authors predict that a mixture of suitable technologies will eventually prevail. They have also come to the conclusion that significant development needs exist regarding energy storage, demand side management as well as electrical transmission and distribution networks. Promoting innovation in these areas requires, amongst others, a concept aimed at removing obstacles which arise from existing financial support of other energy technologies. So as to create a better basis for political measures, systems studies and scientific policy advisory work should also be expanded. Moreover, the authors perceive a need for amendments to be made in the legal field. Some important keywords in this context include: legal assignments of storage applications to the level of the generator or network, planning processes, how to deal with the large amounts of regularly generated sensitive data and the regulation of the manifold new business relationships which arise.

Economic Analysis and Policy

Having discussed technical requirements, potentials and costs for balancing technologies in the previous sections, this chapter investigates problems in a market economy with electricity supply that changes with weather conditions and incentives to balance supply and demand (see Sect. 7.1). This is followed by an analysis of the reasons and potentials for politically manipulating economic framework conditions (see Sect. 7.2). The results are finally summarised and concluded in Sect. 7.3.

Challenges and Recommendations

The overall aim of restructuring Germany’s and Europe’s electricity systems is to reduce their environmental burden to a level that is viable for long-term future application. This requires that a system be subsequently developed which, based on current knowledge, can cope simultaneously with fundamental demands for economic efficiency, environmental friendliness and supply security. Making use of existing scenarios, this study sketches out such a system with the focus laid on auxiliary systems such as energy storage methods and network extensions.

Review of the Need for Storage Capacity Depending on the Share of Renewable Energies

Abstract The need for storage capacity depending on the share of renewable energies is discussed based on the review of 16 relevant studies with the focus on Germany and Europe. Furthermore, the transferability to other situations is analyzed. Several estimates for required storage power and energy capacity can be derived from the studies, which at the same time reflect particularly the influence of the technology mix for the energy supply system assumed. Thus, an analysis of total balancing need caused by the use of fluctuating renewable energy sources was found to be more promising than the analysis of the need for storage or the potential for specific storage technologies. The analysis of the general transferability of results on balancing and storage need from one region to another shows that a use of estimates for other situations requires an adequately detailed case-dependent consideration of various framework conditions.

Political Challenges in Managing Transitions of Energy Systems Beyond Pure Energy-Economic Modelling

The political model of the social planner, or benevolent dictator, upon which economic energy system modelling is based, is greatly simplified. Real situations are much more complex. The various administrative levels with their different legislative expertise or the plurality of regions and nations involved in decisions about the future energy supply are not sufficiently examined in techno-economic analyses of the energy sector as outlined in the previous chapters.

Demand for Balancing Electrical Energy and Power

One important estimate to consider when trying to determine the most appropriate policy options is in which cases, and to what extent, a demand for balancing electrical energy and power exists which cannot be covered by the installed energy conversion systems themselves.

Specific Economic Problems and Uncertainties in the Context of Energy Systems

With the construction of the characterisation scheme in the last chapter it became clear that some areas which are relevant for the energy supply system can only be covered via assumptions. For usual modelling this holds particularly true for the problems of sustainable energy policy discussed here.

Characterisation of Recent Energy System Analyses

The discussions in the previous chapters have made clear that valuable analyses which can be used for policy decision-making must take into consideration the striking issues and interrelations, rather than the details, of the relevant systems. Additionally, such analyses must be transparent and, as far as possible, show the whole range of options. Furthermore, the analyses need to fit the specific purpose under consideration.

Prospects and Limits of Scientific Policy Advice for Future Energy Systems

The discussion in Chap. 2 showed that, if its findings are at least partially reliable, scientific policy advice based on the analysis of relevant aspects of technical and basic ethical principles can prove helpful in the decision-making process. However, the reliability of future-related statements is in principle limited, making the future development of energy systems subject to risks and uncertainty, as was shown in the discussion of dynamic stability in Sect. 2.3.1.

Framework for the Development of a Long-Term Viable Energy System

In order to realise a long-term viable energy system, various aspects have to be taken into account. On the one hand, overall targets of the society and general aims of the energy system have to be considered in order to define what a desired solution might resemble. On the other hand, the complexity and interweavement of the energy supply system with the society have to be taken into account with regard to recommendations and the design of adequate advisory procedures.