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2020
Report
Titel
Multi-Sektor-Kopplung
Titel Supplements
Modellbasierte Analyse der Integration erneuerbarer Stromerzeugung durch Kopplung der Stromversorgung mit dem Wärme, Gas- und Verkehrssektor. Endbericht
Abstract
The project provides a model based analysis of the combined implementation of different flexibilities and sector coupling options in a future energy system with high shares of renewable energy. It is based on a techno-economic approach that is re-solved in time and space. This approach provides the basis to assess various energy economic frameworks concerning the resulting investments and dispatch choices. The novelty of the project lies in the focus on the design of the coupling of electricity and gas systems as well as in the combination of the macroeconomic and the business perspective. The energy system model REMix covers the overall system perspective by optimizing system cost of future energy systems. It enables the assessment of infrastructure requirements during the energy system transformation, as well as the hourly technology dispatch. The model comprises electricity, heat and gas supply and parts of the transport system. The implementation of the gas sector into the model is one of the major methodological achievements of this project. The model MuGriFlex on the other hand represents individual systems on a local level from the perspective of the investor or operator. It simulates the hourly operation of technologies over one year and determines the cost-effective deployment of energy converters as well as storage. This enables dimensioning system components, and assessing economic feasibility and integration into the overall energy system. The project required modelling temperature dependent components, such as solar thermal collectors, heat pumps and the heat network in greater detail and embed-ding equipment of the gas infrastructure. Further improvements concern heat losses in storage as well as the evaluation of economic efficiency for all plant types. The optimized system configuration determined with REMix is co-assessed with the strategies that result from the regulatory framework for individual systems. Dimensioning and hourly operation profiles, as well as time series of electricity production cost and the mix of gaseous fuels form the central points of model coupling. Electricity and gas costs for example enter the analysis of individual systems based on the results of the overall system optimization concerning electricity and gas production in the various scenarios. The model-based analysis of future energy systems relies on two framework scenarios that represent normative transformation paths for Germany and its European neighbours. They reflect different target values for CO2 emission reduction up to the year 2050. These target scenarios are used for the parameterization of the REMix model and thus set the energy-economic context for the entire project. Currently the main drivers of economic feasibility for the plants analysed in MuGri-Flex are subsidies and surcharges for combined heat and power plants (CHP), as well as the prices for electricity and gas. For the analysis of individual local systems, those parameters were updated for future years in accordance with the scenarios as far as possible. During the period under consideration, however, further structural changes could occur, for example concerning network tariffs or additional, local flexibility markets. Additionally, the project assembled the technological aspects most relevant to modelling the gas system. These comprise gas preheating, compression, storage and transport, as well as the feed-in of hydrogen, biogas or synthetic methane into the existing gas infrastructure. Particularly for equipment within the gas network, the project compiled a new detailed database. Yet, future gas quality and standards, as well as the energy economic framework for new infrastructures remain in discussion. For the analysis in REMix extensive data concerning the gas system was condensed for a simplified representation in the model while required inputs were aggregated and converted to conform to the model logic. The results from overall system optimization for the two target scenarios underline the positive interaction of different options of flexible coupling between the electricity, heat and gas systems. As the reduction of CO2 emissions progresses, sector coupling gains in importance for balancing fluctuating electricity generation from wind and solar sources. In a scenario without direct emissions in the analysed energy system, the deployment of extensive hydrogen infrastructure proves economically efficient. Variation of selected scenario assumptions such as technology costs and potentials e.g. in the case of renewable energy production or load balancing impacts the future composition of the energy technology portfolio and shows how technology options may substitute each other. Differences between the perspectives on the overall and on individual systems lead to deviating results, mainly concerning CHP, heat pumps and PtG plants. The results depend on the respective scenarios and regions, as well as occasionally on the inter-play with other technology options. The analysis shows how regulatory changes, i.e. subsidies or rebates on surcharges, can in principle correct the incentives and even out the discrepancy between overall and individual system optimum. The representative example of the model region ""Hessen, Rhineland-Palatinate and Saarland"" illustrates, that the given framework does not foster optimal investments in CHP and electric boilers. Furthermore it shows that CHP and Power-to-Heat would not operate efficiently. Subsidies and rebates can optimize the system with manifold interdependencies to be considered. For bi-fuel equipment within the gas infrastructure the electric operation is optimal in the future scenarios from individual both perspectives. Investments in Power-to-Gas plants do not become feasible within the scenarios considered. Their operation becomes feasible only in 2050, even if no contribution is required to the initial investment. A subsidy or rebate on surcharges can correct the incentives, but would require careful calibration and bring about substantial expenditure given the significant role of synthetic gases from the overall system's per-spective. The project results highlight the opportunities of a closer integration of electricity, heat and gas supply, but also the associated regulatory challenges for incentivizing a system-friendly operation and investment. In the extended methods and collected data, the work provides an important basis for further research focused on the implementation of flexible sector coupling in the energy system transformation.
Author(s)
Brandstätt, Christine
Gils, Hans Christian
Institut für Technische Thermodynamik Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)
Gardian, Hedda
Institut für Technische Thermodynamik Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)
Pregger, Thomas
Institut für Technische Thermodynamik Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)
Beteiligt
Roller, Isabelle Dominique
Cebulla, Felix
Institut für Technische Thermodynamik Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)
Meyer, Eileen
Institut für Technische Thermodynamik Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)
Verlag
Fraunhofer IFAM
Verlagsort
Bremen