A comparative co-simulation analysis to improve the sustainability of cogeneration-based district multi-energy systems using photovoltaics, power-to-heat, and heat storage

For an extensive decarbonization of district multi-energy systems, efforts are needed that go beyond today\u27s cogeneration of heat and power in district multi-energy systems. The multitude of existing technical possibilities are confronted with a large variety of existing multi-energy system configurations. The variety impedes the development of universal decarbonization pathways. In order to tackle the decarbonization challenge in existing and distinct districts, this paper calculates a wide range of urban district configurations in an extensive co-simulation based on domain specific submodels. A district multi-energy system comprising a district heating network, a power grid, and cogeneration is simulated for two locations in Germany with locally captured weather data, and for a whole year with variable parameters to configure a power-to-heat operation, building insolation/refurbishment, rooftop photovoltaic orientation, future energy demand scenarios, and district sizes with a temporal resolution of 60 seconds, in total 3840 variants. The interdependencies and synergies between the electrical low-voltage distribution grid and the district heating network are analysed in terms of efficiency and compliance with network restrictions. Thus, important sector-specific simulations of the heat and the electricity sector are combined in a holistic district multi-energy system co-simulation. The clearly most important impact on emission reduction and fuel consumption is a low heat demand, which can be achieved through thermal refurbishment of buildings. Up to \SI{46}{\percent} reduction in $CO_2$ emissions are possible using the surplus electricity from photovoltaics for power-to-heat in combination with central heat storage in the district\u27s combined heat and power plant. Domestic hot water heated by district heating network in combination with power-to-heat conversion distributed in the district reduces the load on the distribution power grid. Even though the investigated measures already improve the sustainability significantly, providing the energy needed for the production of synthetic fuels remains the crucial challenge on the further path towards net-zero

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INST: Szakdolgozatok (GTK) - Szakdolgozatok (GTK)Alza közösségi médiás aktivitás elemzés

Economic and ecologic evaluation of low temperature waste heatintegration into existing district heating

The integration of waste heat into district heating offersthe potential to decrease the environmental impactof the district heating's energy supply. A signi-cant amount of waste heat is available at low temperatures,compared to existing district heating networks.In this paper, we generate a simulation model of a districtheating network from a database and evaluatethe integration of waste heat compared to the originaldesign. Our simulation demonstrates the feasibility ofintegrating low temperature waste heat into an existingnetwork. The waste heat utilization can decreasethe primary energy consumption and CO2 emissionsfor the respective buildings. These results can beimproved further by optimizing the low-temperaturenetwork connection of each building

Economic and Ecologic Evaluation of Low Temperature Waste Heat Integration Into Existing District Heating

The integration of waste heat into district heating of-fers the potential to decrease the environmental im-pact of the district heating’s energy supply. A signifi-cant amount of waste heat is available at low tempera-tures, compared to existing district heating networks.In this paper, we generate a simulation model of a dis-trict heating network from a database and evaluatethe integration of waste heat compared to the originaldesign. Our simulation demonstrates the feasibility ofintegrating low temperature waste heat into an exist-ing network. The waste heat utilization can decreasethe primary energy consumption and CO2emissionsfor the respective buildings. These results can beimproved further by optimizing the low-temperaturenetwork connection of each building

Design optimization of a heating network with multiple heat pumps using Mixed Integer Quadratically Constrained Programming

District heating is a state of the art technology for efficient supply of heat. Modern 4th generation and 5th generation district heating networks can be used to integrate sources of waste heat, which allows efficient operation. The design of such heating networks is subject of many optimization models. Most optimization models focus on energy flows and result in Mixed Integer Linear Programs. This requires simplifications, where temperatures and mass flow rates are neglected or simplified. This work presents a Mixed Integer Quadratically Constrained Program with temperature constraints. A case study is presented, where the integration of low temperature waste heat in a district heating network is optimized. In this case study the positioning of heat pumps at the supply or at the consumers influences network operation. The results show a trade-off between economical and ecological optimal solutions with a range of total annualized costs from 120,000 EUR/a to 307,000 EUR/a and a range of CO2-Emissions from 193 t/a to 605 t/a. Furthermore, the influence of design decisions on the optimal operation is demonstrated. All in all, the quadratic model formulation stresses the influence of temperatures on the optimization outcome and offers pareto optimal solutions for the design of the presented case study

Ecological and Economic Analysis of Low-TemperatureDistrict Heating in Typical Residential Areas

Potential waste heat integration in low-temperature district heating (LTDH) systems is a main task for future sustainable heat supply. For evaluation of efficient LTDH integration in residential areas, investigations of the typical building stock are useful. In this study, we present an economic and ecologic investigation of two LTDH supply temperatures in multiple typical residential areas. We show which design have the strongest impact on efficient heat supply in terms of electricity usage and low specific heating costs. Therefore, we design nine representative residential areas derived from dwelling types of the German building stock. Within these areas, we investigate LTDH supply performance in combination with decentralized boosting heat pumps. In addition, we compare the results to an individual heat supply by air-water-heat pumps. The results show that the fraction of domestic hot water on total heat demand and the design of decentralized heat pump systems capacities impact LTDH operation efficiency. LTDH network installation with operation temperatures around 60 °C are most advantageous in residential areas with a high share of space heating demand

Modernization Roadmaps for Existing Buildings under Limited Energy Resources and Craftwork Capacities

Great potential for saving carbon emissions lies in modernizing European buildings. Multi-year modernization roadmaps can plan modernization measures in terms of time and are able to consider temporal interactions. Therefore, we have developed a mixed-integer program that determines modernization roadmaps. These roadmaps include changing the energy supply system, improving the envelope, and considering annually varying boundary conditions. High craftwork capacities are required to implement the necessary modernizations to meet climate goals. Unfortunately, studies showed that the current shortage of craftworkers will intensify in the next years. Other important limitations correspond to energy resources. Recent crises show that many energy systems need to handle these limitations. Therefore, we extended the mixed-integer program by a method to handle these limitations inside the roadmaps. By the use of data from 90 interviews with craftwork specialists about the time needed to realize modernization measures, the method is applied. The main purpose is to analyze how modernization strategies change under limited resources, especially in terms of craftwork capacities. Hence, the method is exemplified by a representative single-family dwelling. Within this use case, modernization roadmaps with different craftwork capacity levels were calculated. The results show that modernization roadmaps change comprehensively over these levels. Key findings are that costs and emissions rise with decreasing craftwork capacities. Furthermore, smaller storages and pv systems are implemented at low craftwork capacities. The electrification of the heat supply supported by medium insulation standards should also be implemented with limited craftwork capacities

Energiewende im Quartier: Living Lab Energy Campus im FZJ

Mit dem Projekt Living Lab Energy Campus vollzieht das Forschungszentrum Jülich (FZJ) als eine Stadt im Kleinen auch die Energiewende im Kleinen.Energiewende im Großen oder im Kleinen bedeutet dabei einen Wechsel von einer klassischen klar hierarchisch geordneten zentralen Versorgung hin zu einer immer stärker dominierten dezentralen Energieversorgung unter Einbindung erneuerbarer Energien. Damit ergibt sich ein Schritt von kontinuierlich betriebenen, zentralen Einheiten hin zu einem komplexen, zeitlich dynamischen, dezentralen und Nachfrage-Angebot-bestimmten System

Integrating Usability-Engineering into the Software Developing Processes of SME: A Case Study of Software Developing SME in Germany

Usability is an important factor for product quality. For German small and medium enterprises (SME) in the software branch, cheaper producing vendors from foreign countries can be considered as serious competition. Improving the usability of software products is a good way to secure competitiveness. However, integrating usability-engineering into development is a challenge for SME. In this note, we present the empirical results of a research project study with focus on software engineering processes in German software SME and possible constraints and chances for integrating usability-engineering