Techno-economic assessment and optimization of seasonal thermal energy storage in district heating networks

Project Description

Today, the heating sector is not on track toward achieving the IEA Net Zero Emission scenario’s targets, residential, commercial and industrial heat demand below 150°C represent more than a third of the overall EU energy demand and it mainly relies on fossil fuels. Thus, it represents a major challenge to face to achieve a climate neutral economy by 2050 as set by the European Climate Law and Green Deal. Possible solutions include an efficient integration of local renewable energy sources (RES), aiming at their maximal exploitation, and the use of various forms of excess and waste heat sources that otherwise would remain untapped or just wasted. District heating (DH) is recognized as a major solution allowing decarbonisation of the heating sector by integrating renewable and carbon neutral energy sources and relative technologies while contributing to energy system coupling. DH can also provide flexibility on the electricity market via power-to-heat solutions such as large-scale heat pumps or via combined heat and power (CHP) plants, to accommodate renewable electricity production. However, to attain all of these advantages the integration of large-scale, seasonal TES solutions, and its full interaction with DHN, is crucial and part of the strategic agenda and a key cross-cutting technology for modern fully decarbonized heating system. One of the major challenges for future energy systems, and particularly for the heating sector largely affected by seasonality, is to overcome the mismatch between supply and demand. The deployment of large-scale TES can facilitate the interlinking between the electricity and the heating sectors, enabling a larger penetration of intermitted RES both at the power and heat generation side and optimized management of more traditional plants like cogeneration units (CHP), widely used in current DHN.

Seasonal thermal energy storages are currently underdeveloped and only pit storage have attained full commercialization notwithstanding some technical challenges and scalability constraints. Alternative underground seasonal TES, such as boreholes and aquifer TES, have been proposed and partially tested, generally up to limited sizes and with limited technological integration.

The aim of this thesis is to develop techno-economic models and assessments to investigate the performance of seasonal thermal energy storage integration and renewables-based district heating networks. In doing so, the student will contribute to the Horizon Europe project USES4HEAT. The specific replication scenarios and system integration to be assess will be identified in the early stages of the Thesis based on the students’ interest and the specific cases set by the pool of replication cases and large set of DHN operators involved in the project.

Main Deliverables

The main deliverables of the project include:

• Final project report and presentation comprising description of project, literature review, integrated solution definition via specific layout and operation descriptions, techno-economic modelling technique (including main assumptions and equations), techno-economic performance assessment and system optimization, and final suggestions.
• TEA models: models and user guidelines / instructions.

Duration

The project should start in January/February 2024 the latest, and should not extend for more than 6 months.

Specific starting date to be discussed.

Location

KTH - Energy Department.

Main Supervisor

Researcher, Heat and Power Division

Examiner

Professor, Heat and Power Division