Analysis and assessment of flexibility in multi-energy systems

  • Adrien Saint-Pierre

Student thesis: Phd


The rapidly growing global energy demand creates unprecedented challenges to meet the ambitious environmental targets to reduce greenhouse gas emissions. Even though coal and natural gas still account for the major share of primary energy consumption in the power sector, the share of renewable, but intermittent, energy sources is increasing rapidly. This trend is creating a grand challenge in the power sector as on the one hand, increased flexibility is needed to foster for the integration of renewables while, on the other hand, the relevant flexible units would reduce opportunities for less flexible but more efficient Low Carbon Technologies (LCTs) such as Carbon Capture and Storage (CCS). In light of the above, it is vital to identify alternative sources of flexibility. An attractive option is to look beyond the power sector and into the multi-energy paradigm. This provides new sources of flexibility as (i) technologies from different sectors can now be coupled to increase their technical, environmental and economic performance (e.g., exploiting heat from cogeneration to support CCS) and (ii) energy surplus and shortage issues introduced by intermittent generation can be tackled through the use of different energy sources (e.g., Power-to-Gas and Power-to-Heat). This thesis proposes new methodologies to analyse and assess flexibility in multi-energy systems at both generation and distribution levels. The first contribution is the development of a model that optimises the operation of flexible CCS coal-fired cogeneration plants in a volatile market environment. The second contribution is the development of a model and tool for the simulation of electricity distribution networks with multi-energy resources taking both network and scheduling constraints into account. The third contribution is the design of an active distribution system management framework to assess the flexibility in distribution networks with multi-energy assets and a comprehensive treatment of uncertainties. The flexibility map concept is then proposed as an original methodology to quantify the operational flexibility available from the whole distribution system in power, energy, and ramp-rate capacity, paving the way to new flexibility services. The developed models and methodologies are incorporated into a number of case studies showing their applicability and relevance to assess flexibility in multi-energy systems.
Date of Award31 Dec 2017
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorJohn Moriarty (Supervisor) & Pierluigi Mancarella (Supervisor)


  • smart grid
  • energy transition
  • optimisation
  • carbon capture
  • flexibility
  • multi-energy systems
  • power systems
  • active distribution network

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