NachhaltigEuropan Campus Rottal-InnBeitrag (Sammelband oder Tagungsband)
Matthias Huber, F. Sanger, T. Hamacher
Coordinating smart homes in microgrids: A quantification of benefits
2013 4th IEEE/PES Innovative Smart Grid Technologies Europe (ISGT EUROPE)
DOI: 10.1109/ISGTEurope.2013.6695357
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A growing number of households are seeking energy autonomy and economic benefits by installing micro-CHP and PV generators, as well as battery storage units in their so-called smart homes. An option to further increase benefits, is to install a community microgrid and coordinate smart homes intelligently. To quantify this increase, we apply numerical simulations using real-world data for household loads in a temporal resolution of 15-minutes. In systems consisting of CHP-units, the degree of electricity autonomy rises from 50% to 80% through installing a microgrid, allowing lucrative CHP operation. In PV-based systems, the benefits are fewer and if battery storage is installed additionally, they almost disappear completely. As a consequence, intelligently managed microgrids are as valuable option for the integration of microgeneration as long as decentralized battery storage is not profitable and thus not employed.
NachhaltigEuropan Campus Rottal-InnBeitrag (Sammelband oder Tagungsband)
Matthias Huber, M. Silbernagl
Modeling start-up times in unit commitment by limiting temperature increase and heating
Proceedings of the 2015 12th International Conference on the European Energy Market (EEM)
DOI: 10.1109/EEM.2015.7216755
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The integration of variable renewable energy sources leads to an increased cycling of conventional power plants, necessitating a detailed model of the start-up process. Based on the recently developed temperature formulation for startup costs in Unit Commitment, we model the off-time-dependent start-up times of thermal units by limiting temperature increase and heating. Numerical results indicate that limiting heating speed is more efficient and leads only to a moderate increase in computational time.
NachhaltigEuropan Campus Rottal-InnBeitrag (Sammelband oder Tagungsband)
T. Deetjen, M. Webber, Matthias Huber
Optimizing capacity extensions in power systems: A case study of Bavaria and a comparison to Texas
Proceedings of the 2017 14th International Conference on the European Energy Market (EEM)
DOI: 10.1109/EEM.2017.7981908
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As the German Energiewende policy enters the latter stages of its goal to dismantle the country's nuclear power plant fleet, the southern state of Bavaria must decide how it will replace its nuclear generation capacity. This study extends a renewable capacity expansion model that was initially developed to find optimal extensions of wind and solar generation and transmission for Texas, United States. Here, additional options for the development of the Bavarian electricity supply are added: combined-heat-and-power (CHP), improving transmission connections to the non-Bavarian German generator fleet, and constructing new natural gas combined cycle (CCGT) power plants within Bavaria. The model's solution suggests that an optimal mix includes 3.5 GW of transmission to the non-Bavarian generator fleet, 6.0 to 9.5 GW of new CCGT capacity, and 8.5 to 10.0 GW of transmission capacity to the on-shore wind resources of the Schleswig-Holstein state in northern Germany, depending on the CO 2 price. Compared to the model results for Texas, Bavaria's system is less sensitive to a CO 2 price in both the optimal system configuration and the resulting emissions. While Texas emissions can be reduced by 55% with a CO 2 price increase from 10 to 100 $/ton, the reduction in Bavaria is only 28% with a price increase from 0 to 100 EUR/ton.
NachhaltigEuropan Campus Rottal-InnBeitrag (Sammelband oder Tagungsband)
N. Vespermann, Matthias Huber, S. Paulus, M. Metzger, T. Hamacher
The Impact of Network Tariffs on PV Investment Decisions by Consumers
2018 15th International Conference on the European Energy Market (EEM)
DOI: 10.1109/EEM.2018.8469944
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The increasing amount of self-produced energy reduces the customer base of network utilities. Assuming constant grid costs, network charges have to be increased in systems applying volumetric network tariffs. In order to understand the cost recovery problem of utilities, it is crucial to analyze consumers' PV investment and operation decisions as sources of self-produced energy. This work proposes a mathematical framework that determines PV investment by consumers subject to the day-ahead market. Volumetric and capacity network tariffs are considered, which are altered by consumers' day-ahead market demand. The optimal PV investment from a central planner's perspective serves as a benchmark. The results show that a volumetric network tariff incentivizes inefficient investments in distributed PV systems, which causes all consumers' energy costs to increase. In contrast, a capacity network tariff reduces these incentives as consumers cannot offset their expected burden of network costs by installing PV systems.
NachhaltigEuropan Campus Rottal-InnBeitrag (Sammelband oder Tagungsband)
M. Küppers, M. Metzger, Matthias Huber, S. Paulus
Archetypes of Country Energy Systems
2019 IEEE Milan PowerTech Conference
DOI: 10.1109/PTC.2019.8810765
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Global challenges as decarbonization, the integration of renewables or an increasing electrification are confronting countries worldwide. Based on an analysis of different energy system models, archetypes of country energy systems are identified as an approach to simplify modeling the global challenges for most countries around the world. Applying a modified K-means algorithm to a broad and transparent data basis of socio-economic, geographic/climatic and energy-related data leads to the definition of the archetypes. An exemplary clustering of 140 countries generating 15 archetypes underlines the existence of patterns in energy systems, which can e.g. be characterized by the climatic circumstances or the energy mix. Overall the archetypes represent a possibility to summarize countries on a global level, leading to a simplified modeling process of countries in energy system models, providing a common data basis for models and identifying common challenges of different countries.
NachhaltigEuropan Campus Rottal-InnBeitrag (Sammelband oder Tagungsband)
O. Walter, Matthias Huber, Kueppers. M., A. Tremel, S. Becker
Energy system design for deep decarbonization of a sunbelt city by using a hybrid storage approach
Proceedings of the 13th International Renewable Energy Storage Conference 2019 (IRES 2019), vol. Vol. 4
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With continuously falling cost of renewable power generation and ambitious decarbonization targets, renewable sources are about to rival fossil fuels for energy supply. For a high share of fluctuating renewable generation, large-scale energy storage is likely to be required. In addition to selling electricity, the reliable supply of heat and cold is a further interesting revenue pool, which makes hybrid storage technologies an interesting option. The main feature of hybrid energy storage – as defined here - is to offer charging and especially discharging in different forms of energy by combining different charging, discharging and storage devices. They can address various demands (e.g. electricity and cold) simultaneously. Two hybrid storages, pumped thermal energy storage (PTES) and power-to-heat-to-x (x: heat and/or electricity) energy storage (PHXES), are investigated based on a techno-economic analysis within this work. Both hybrid storage technologies are charged with electricity and can supply heat and electricity during discharging. They are implemented into a simplified energy system model of a prototype city in the earth’s sunbelt in the year 2030 to find a cost-optimal configuration. Different cases are evaluated: a power-to-power case (P2P), where only an electric demand must be addressed and a power-to-power-and-cooling (P2P&C) case, where the electric demand from the P2P case is divided into a residual electric demand and a cooling demand. For both cases, a natural gas-based benchmark scenario and a decarbonized, renewable-based scenario including the hybrid energy storage technologies are calculated. Both, total expenditures and CO2 emissions are lower in the P2P&C scenarios compared to P2P scenarios. PHXES plays a major role in both cases. PTES is part of the cost-optimal solution in the P2P&C decarb scenario, only if its specific cost are further decreased.
NachhaltigEuropan Campus Rottal-InnZeitschriftenartikel
T. Hamacher, Matthias Huber, J. Dorfner, K. Schaber, A. Bradshaw
Nuclear fusion and renewable energy forms: Are they compatible?
Fusion Engineering and Design, vol. 88, no. 6-8, pp. 657-660
DOI: 10.1016/j.fusengdes.2013.01.074
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Nuclear fusion can be considered as a base-load power plant technology: High investment costs and limited operational flexibility require continuous operation. Wind and solar, on the other hand, as the putative main pillars of a future renewable energy system, are intermittent power sources. The resulting variations that occur on many different time scales require at first sight a rather flexible back-up system to balance this stochastic behavior. Fusion would appear not to be well suited for this task. The situation changes, however, if a large-scale renewable energy system is envisaged based on a transnational, or even transcontinental power grid. The present paper discusses a possible European power system in the year 2050 and beyond. A high percentage share of renewable energies and a strong power grid spanning the whole of Europe and involving neighboring countries, in particular those in North Africa, are assumed. The linear programming model URBS is used to describe the power system. The model optimizes the overall system costs and simulates power plant operation with an hourly resolution for one whole year. The geographical resolution is at least at the country level. The renewable technologies are modeled first on a more local level and then summed together at the country or regional level. The results indicate that the smoothing effects of the large-scale power grid transform the intermittent renewable supply, which is then more compatible with base-load power plants such as fusion reactors.
NachhaltigEuropan Campus Rottal-InnZeitschriftenartikel
Matthias Huber, D. Dimkova, T. Hamacher
Integration of wind and solar power in Europe: Assessment of flexibility requirements
Energy, vol. 69, no. 1 May 2014, pp. 236-246
DOI: 10.1016/j.energy.2014.02.109
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Flexibility is the ability of a power system to respond to changes in power demand and generation. Integrating large shares of variable renewable energy sources, in particular wind and solar, can lead to a strong increase of flexibility requirements for the complementary system, traditionally hydrothermal, which has to balance the fluctuations of variable generation. We quantify these flexibility requirements at the operational timescale of 1–12 hours and different spatial scales across Europe. Our results indicate that three major factors determine the ramping flexibility needed in future power systems: the penetration of variable renewables, their mix and the geographic system size. Compared to the variability of load, flexibility requirements increase strongly in systems with combined wind and PV (photovoltaics) contribution of more than 30% of total energy and a share of PV in the renewables mix above 20–30%. In terms of extreme ramps, the flexibility requirements of a geographically large, transnational power system are significantly lower than of smaller regional systems, especially at high wind penetration.
NachhaltigEuropan Campus Rottal-InnZeitschriftenartikel
Matthias Huber, C. Weissbart
On the optimal mix of wind and solar generation in the future Chinese power system
Energy, vol. 90, no. October, pp. 235-243
DOI: 10.1016/j.energy.2015.05.146
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China is one of the largest and fastest growing economies in the world. Until now, the corresponding growth of electricity consumption has been mainly provided by coal. However, as national reserves are limited and since burning coal leads to severe environmental problems, the employment of alternative sources of energy supply has become an important part of the Chinese energy policy. Recent studies show that wind energy alone could meet all of China's electricity demand. While our results validate these findings with regard to annual production, we look at the hour-by-hour resolution and uncover a major limitation: wind generation will not match the demand at every given point in time. This results in significant periods with over- and undersupply. Our study shows that combining wind and solar generation in the power system reduces overproduction significantly and increases the capacity credit of the combined VRE (variable renewable energy sources). The article demonstrates that up to 70% of VRE comprising 20–30% solar generation in the form of photovoltaics (PV) can be integrated into China's electricity system with moderate storage requirements. We encourage planners to consider those findings in their long-term planning in order to set up a sustainable power system for China at low costs.
NachhaltigEuropan Campus Rottal-InnZeitschriftenartikel
Matthias Huber, A. Roger, T. Hamacher
Optimizing long-term investments for a sustainable development of the ASEAN power system
Energy, vol. 88, no. August, pp. 180-193
DOI: 10.1016/j.energy.2015.04.065
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The electricity consumption in the ASEAN (Association of East Asian Nations) region is one of the fastest growing in the world and will lead to a dramatic increase in greenhouse gas emissions in the next decades. A decarbonization of the region's electricity supply is thus a very important measure when taking action on global climate change. This paper defines cost-optimal pathways towards a sustainable power system in the region by employing linear optimization. The proposed model simultaneously optimizes the required capacities and the hourly operation of generation, transmission, and storage. The obtained results show that all different kinds of renewable sources will have to be utilized, while none of them should have a share of more than one third. The findings give reason for setting up an ASEAN power grid, as it enables the transportation of electricity from the best sites to load centers and leads to a balancing of the fluctuations from wind and solar generation. We suggest fostering a diversified extension of renewables and to elaborate on political and technical solutions that enable the build up an transnational supergrid.
NachhaltigEuropan Campus Rottal-InnZeitschriftenartikel
M. Silbernagl, Matthias Huber, R. Brandenberg
Improving Accuracy and Efficiency of Start-Up Cost Formulations in MIP Unit Commitment by Modeling Power Plant Temperatures
IEEE Transactions on Power Systems, vol. 31, no. 4, pp. 2578-2586
DOI: 10.1109/TPWRS.2015.2450776
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This paper presents an improved mixed-integer model for the thermal unit commitment problem. By introducing new variables for the temperature of each thermal unit, the off-time-dependent start-up costs are modeled accurately and with a lower integrality gap than state-of-the-art formulations. This new approach significantly improves computational efficiency compared to existing formulations, even if they only model a rough approximation of the start-up costs. Our findings were validated on real-world test cases using CPLEX.
NachhaltigEuropan Campus Rottal-InnZeitschriftenartikel
P. Kuhn, Matthias Huber, J. Dorfner, T. Hamacher
Challenges and opportunities of power systems from smart homes to super-grids
Ambio, vol. 45, no. S1, pp. 50-62
DOI: 10.1007/s13280-015-0733-x
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The world’s power systems are facing a structural change including liberalization of markets and integration of renewable energy sources. This paper describes the challenges that lie ahead in this process and points out avenues for overcoming different problems at different scopes, ranging from individual homes to international super-grids. We apply energy system models at those different scopes and find a trade-off between technical and social complexity. Small-scale systems would require technological breakthroughs, especially for storage, but individual agents can and do already start to build and operate such systems. In contrast, large-scale systems could potentially be more efficient from a techno-economic point of view. However, new political frameworks are required that enable long-term cooperation among sovereign entities through mutual trust. Which scope first achieves its breakthrough is not clear yet.
Europan Campus Rottal-InnZeitschriftenartikel
R. Brandenberg, Matthias Huber, M. Silbernagl
The summed start-up costs in a unit commitment problem
EURO Journal on Computational Optimization, vol. 5, no. 1-2, pp. 203-238
DOI: 10.1007/s13675-016-0062-2
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We consider the sum of the incurred start-up costs of a single unit in a Unit Commitment problem. Our major result is a correspondence between the facets of its epigraph and some binary trees for concave start-up cost functions CU, which is bijective if CU is strictly concave. We derive an exponential H-representation of this epigraph, and provide an exact linear separation algorithm. These results significantly reduce the integrality gap of the Mixed Integer formulation of a Unit Commitment Problem compared to current literature.
NachhaltigEuropan Campus Rottal-InnZeitschriftenartikel
C. Müller, T. Falke, A. Hoffrichter, L. Wyrwoll, C. Schmitt, M. Trageser, A. Schnettler, M. Metzger, Matthias Huber, M. Küppers, D. Most, S. Paulus, H. Heger
Integrated Planning and Evaluation of Multi-Modal Energy Systems for Decarbonization of Germany
Energy Procedia, vol. 158, no. February, pp. 3482-3487
DOI: 10.1016/j.egypro.2019.01.923
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For a successful realization of the energy transition and a reduction of greenhouse gas emissions, an integrated view of multiple energy sectors (electricity, heat and mobility) is necessary. The coupling of different energy sectors is seen as an option to achieve the climate goals in a cost-effective way. In this paper, a methodical approach for multi-modal energy system planning and technology impact evaluation is presented. A key feature of the model is a coupled consideration of sectors electricity, heat and mobility. Energy demands, conversion and storage technologies in households, the Commerce, Trade and Services (CTS) area and the industry are modelled employing a bottom-up modelling approach. The model can be used for the calculation of a detailed transition pathway of energy systems taking into account politically defined climate goals. Based on these calculations, in-depth analyses of energy markets as well as transmission and distribution grids can be performed.
NachhaltigEuropan Campus Rottal-InnZeitschriftenartikel
C. Müller, A. Hoffrichter, L. Wyrwoll, C. Schmitt, M. Trageser, T. Kulms, D. Beulertz, M. Metzger, M. Durckheim, Matthias Huber, M. Küppers, D. Most, S. Paulus, H. Heber, A. Schnettler
Modeling framework for planning and operation of multi-modal energy systems in the case of Germany
Applied Energy, vol. 250, no. 15 September 2019, pp. 1132-1146
DOI: 10.1016/j.apenergy.2019.05.094
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In order to reach the goals of the United Nations Framework Convention on Climate Change, a stepwise reduction of energy related greenhouse gas emissions as well as an increase in the share of renewable energies is necessary. For a successful realization of these changes in energy supply, an integrated view of multiple energy sectors is necessary. The coupling of different energy sectors is seen as an option to achieve the climate goals in a cost-effective way. In this paper, a methodical approach for multi-modal energy system planning and technology impact evaluation is presented. A key feature of the model is a coupled consideration of the sectors electricity, heat, fuel and mobility. The modeling framework enables system planners to optimally plan future investments in a detailed transition pathway of the energy system of a country, considering politically defined climate goals. Based on these calculations, in-depth analyses of energy markets as well as electrical transmission and distribution grids can be performed using the presented optimization models. Energy demands, conversion and storage technologies in households, the Commerce, Trade and Services (CTS) area and the industry are modeled employing a bottom-up modeling approach. The results for the optimal planning of the German energy system until 2050 show that the combination of an increased share of renewable energies and the direct electrification of heat and mobility sectors together with the use of synthetic fuels are the main drivers to achieve the climate goals in a cost-efficient way.
NachhaltigEuropan Campus Rottal-InnZeitschriftenartikel
Kueppers. M., S. Paredes Pineda, M. Metzger, Matthias Huber, S. Paulus, H. Heger, S. Niessen
Decarbonization pathways of worldwide energy systems – Definition and modeling of archetypes
Applied Energy, vol. 285, no. 01 March 2021
DOI: 10.1016/j.apenergy.2021.116438
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Energy system models help to find the optimal technology mixes for decarbonization strategies in countries worldwide. To reduce the modeling effort and analyze as many countries as possible, this paper proposes a novel approach of energy system archetypes which can be directly evaluated. These archetypes classify similar countries worldwide independently from their geographic location. Advantages of this idea are the setup of a transferable global database allowing for data reconstruction between countries, market size estimations, and the ability to compare peer countries facing similar challenges. To enable such modeling, a framework is developed in which the archetypes are defined, standardized modeling rules are developed, and the results are evaluated for validation. In a benchmark against simple geographic classifications, the presented clustering approach, which results in 15 archetypes, improves the variance between all countries and their corresponding archetypes by 44% compared to the variance between the countries and their geographic sub-regions. The model results of these archetypes state the need of balancing technologies for the daily cycle of photovoltaic generation and the general importance of flexibility in future decarbonized energy systems. Overall, the results confirm that archetypes are an adequate approach to derive the set of solutions for the decarbonization of worldwide countries.
DigitalNachhaltigEuropan Campus Rottal-InnZeitschriftenartikel
Kueppers. M., C. Perau, M. Franken, H. Heger, Matthias Huber, M. Metzger, S. Niessen
Data-Driven Regionalization of Decarbonized Energy Systems for Reflecting Their Changing Topologies in Planning and Optimization
Energies, vol. 13, no. 16
DOI: 10.3390/en13164076
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The decarbonization of energy systems has led to a fundamental change in their topology since generation is shifted to locations with favorable renewable conditions. In planning, this change is reflected by applying optimization models to regions within a country to optimize the distribution of generation units and to evaluate the resulting impact on the grid topology. This paper proposes a globally applicable framework to find a suitable regionalization for energy system models with a data-driven approach. Based on a global, spatially resolved database of demand, generation, and renewable profiles, hierarchical clustering with fine-tuning is performed. This regionalization approach is applied by modeling the resulting regions in an optimization model including a synthesized grid. In an exemplary case study, South Africa’s energy system is examined. The results show that the data-driven regionalization is beneficial compared to the common approach of using political regions. Furthermore, the results of a modeled 80% decarbonization until 2045 demonstrate that the integration of renewable energy sources fundamentally changes the role of regions within South Africa’s energy system. Thereby, the electricity exchange between regions is also impacted, leading to a different grid topology. Using clustered regions improves the understanding and analysis of regional transformations in the decarbonization process.