PhD: A Long-term Strategy Framework for Flexible Energy Operation of Residential Buildings

PhD Kasper Emil Thorvaldsen: Thesis for the Degree of Philosophiae Doctor
Faculty of Information Technology and Electrical Engineering, Department of Electric Power Engineering, NTNU, 2022:251. 


Within the European power system, the electricity mix is experiencing more presence of variable power production due to the green shift. This shift causes increased need for flexibility measures to combat instability, which is achievable on both the generation and consumption side of the power system. Buildings, neighborhoods, and most end-users are able to assist with flexibility through demand side management, adjusting their consumption profile to react to the price signals given. This flexibility can be activated through the use of home energy management systems, which can control the flexible assets present in a given building. However, most of these applications only consider the short-term period of operation, up to a couple of days in the future when operating the flexible assets. Flexibility also has a value in operation beyond this period, and can assist in the long-term strategy of operation of the energy system in buildings, which could be many weeks or months into the future. This is important when accounting for long-term price signals or when operating seasonal flexible assets. Finding accurate and descriptive measures of representing the long-term value of flexibility use is needed to enable this.

The work presented in this thesis investigates the long-term value of flexibility in residential buildings at the end-user level, and how the value of flexibility can be represented for a short-term operational model. The work applies and describes a long-term strategy framework specifically aimed at generating cost curves representing the long-term value of flexibility. The cost curves describe the future consequence of operation based on the future price signals they include. The developed models enable price signals of different categories to be included in the strategy framework. These price signals could be grid tariffs, but also flexible assets themselves, for instance, seasonal storage. The strategy framework creates a coupling between short-term and long-term operation of buildings, to achieve better overall use of flexibility within buildings.

Overall, this thesis is made up of four scientific papers, where three are published and one is submitted for review at the present time. These publications comprise the contribution and discussion constituted in this thesis.

The work has been part of a collaborative effort between the research centers Zero Emission Neighborhood (FME ZEN) and Centre for Intelligent Electricity Distribution (FME CINELDI). 

Magnus Korpås

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Magnus Korpås
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Overview of the research papers

  1. K.E. Thorvaldsen, S. Bjarghov, H. Farahmand: "Representing Longterm Impact of Residential Building Energy Management using Stochastic Dynamic Programming", 2020 International Conference on Probabilistic Methods Applied to Power Systems (PMAPS), IEEE, 2020.
  2. K. E. Thorvaldsen, M. Korp˚as, H. Farahmand: "Long-term Value of Flexibility from Flexible Assets in Building Operation", International Journal of Electrical Power & Energy Systems, vol. 138, June 2022.  
  3. K.E. Thorvaldsen, M. Korp˚as, K.B. Lindberg, H. Farahmand: "A stochastic operational planning model for a zero emission building with emission compensation", Applied Energy, vol. 302, 2021.  
  4. K.E. Thorvaldsen, H. Farahmand: "Long-term strategy framework for residential building operation with seasonal storage and capacity-based grid tariffs", under review in Elsevier: Applied Energy, submitted March 2022.