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Title: Bidirectional low temperature district energy systems with agent-based control: Performance comparison and operation optimization

Bidirectional low temperature networks are a novel concept that promises more efficient heating and cooling of buildings. Early research shows theoretical benefits in terms of exergy efficiency over other technologies. Pilot projects indicate that the concept delivers good performance if heating and cooling demands are diverse. However, the operation of these networks is not yet optimized and there is no quantification of the benefits over other technologies in various scenarios. Moreover, there is a lack of understanding of how to integrate and control multiple distributed heat and cold sources in such networks. Thus, this paper develops a control concept based on a temperature set point optimization and agent-based control which allows the modular integration of an arbitrary number of sources and consumers. Afterwards, the concept is applied to two scenarios representing neighborhoods in San Francisco and Cologne with different heating and cooling demands and boundary conditions. The performance of the system is then compared to other state-of-the-art heating and cooling solutions using dynamic simulations with Modelica. The results show that bidirectional low temperature networks without optimization produce 26% less emissions in the San Francisco scenario and 63% in the Cologne scenario in comparison to the other heating and cooling solutions.more » Savings of energy costs are 46% and 27%, and reductions of primary energy consumption 52% and 72%, respectively. The presented operation optimization leads to electricity use reductions of 13% and 41% when compared to networks with free-floating temperature control and the results indicate further potential for improvement. The study demonstrates the advantage of low temperature networks in different situations and introduces a control concept that is extendable for real implementation.« less
 [1] ; ORCiD logo [2] ;  [3] ;  [3]
  1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); RWTH Aachen Univ. (Germany). E. ON Energy Research Center and Inst. for Energy Efficient Buildings and Indoor Climate (EBC)
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  3. RWTH Aachen Univ. (Germany). E. ON Energy Research Center and Inst. for Energy Efficient Buildings and Indoor Climate (EBC)
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Applied Energy
Additional Journal Information:
Journal Volume: 209; Journal Issue: C; Related Information: © 2017 Elsevier Ltd.; Journal ID: ISSN 0306-2619
Research Org:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Building Technologies Office (EE-5B); German Academic Exchange Service (DAAD)
Contributing Orgs:
International Energy Agency (IEA) Energy in Buildings and Communities (EBC) Programme-Annex 60
Country of Publication:
United States
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; Low temperature network; District heating; Urban energy systems; Operation optimization; Modelica; Agent-based control
OSTI Identifier: