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Erstellt u. a. im Rahmen der Forschungs- und Entwicklungsprojekte: „Verbundvorhaben: Geosolare Nahwärmeversorgung für die Siedlung ‚Zum Feldlager‘“ (FKZ: 03ET1336C) im Rahmen des Förderkonzeptes „Energieeffiziente Stadt (EnEff:Stadt)" gefördert durch das Bundesministerium für Wirtschaft und Energie; „Verbundvorhaben: EnEff: Wärme – Smart Thermal Subgrid: Effiziente und erneuerbare Gestaltung von Subnetzen – Umsetzung eines systemischen Ansatzes am Beispiel des Konversionsgebiets Benjamin Franklin Village / Mannheim; Teilvorhaben: Anlagentechnische Integration Erneuerbarer Energien; Betriebsstrategien“ (FKZ: 03ET1580A-C) gefördert durch das Bundesministerium für Wirtschaft und Klimaschutz. Die Verantwortung für den Inhalt dieser Veröffentlichung liegt bei der Autorin.

Large scale heat pumps (HP) are an important technology that will link district heating (DH) systems to the electricity sector in future smart energy systems. This paper examines the feasibility of the integration of a river water HP at a combined heat and power plant in Germany. It is part of a more extensive study about the transformation of a DH system in an urban district towards a 4th generation DH system. The focus is on operational characteristics and economic efficiency of electricity price-driven heat production. A novel method for estimating the coefficient of performance (COP) of two-stage ammonia HPs based on the difference between sink and source temperature is presented. The HP achieves a seasonal COP in the range of 3.4 to 3.7. The 15-year simulation with the software energyPRO shows that electricity-price driven operation is especially relevant for lower heat loads during the non-heating season. The correlation between volatility of electricity market price change and flexible operation is analysed. Finally, the levelized cost of heat for four designs with heat outputs of the HP from 4.7 MWth to 6.1 MWth and increasing storage sizes are compared. The results indicate that electricity costs are reduced in more flexible systems, but cost parity to the minimum dimensioning is not yet reached with the underlying economic framework conditions. However, the parameters that benefit the economic efficiency of more flexible systems are discussed., International Journal of Sustainable Energy Planning and Management, Vol. 31 (2021)

District heating risks to lose competitiveness the lower the linear heat density of a district is. The distribution network needs to be highly efficient in order to ensure economic feasibility. The heat distribution temperatures are crucial to keep distribution heat losses as low as possible. For a new development in Germany consisting mainly of single family houses, two district heating networks at different supply temperature levels are examined in terms of economic and efficiency aspects. Depending on the required temperature level and temperature difference between supply and return the needed volume flow differ. Consequently also the required pipe diameter is affected. The impact of design temperature and operating strategy on the economic feasibility of the district heating network is investigated., International Journal of Sustainable Energy Planning and Management, Vol. 16 (2018)