At the division of Applied Mechanics and Energy Conversion (TME) of the Department of Mechanical Engineering at KU Leuven, the Thermal Systems Simulation (The SySi) Team aims to sustainably use resources through integration and optimisation of thermal systems performance in the built and industrial environment, including other energy vectors.
System integration is key.

Their scientific expertise can mainly be found in: (1) modelling and simulation: from detailed emulator and controller models to reduced models, using object oriented modelling, (2) optimisation and control: optimal design and optimal control, towards integrated optimal control and design (co-design); (3) experimental tests: from lab-scale to pilot plant and field tests to verify and validate models and methods as a proof-of-concept, also including real-life demonstrations.
Starting from domain knowledge is key.

Research topics (most of them investigated in the frame of PhD research) include among others: physics-based modelling (white-box and grey-box) - toward white-box models enriched by data (zebra-box), Model Predictive Control (MPC), Building (and District) Optimization Testing Framework (B(D)OPTEST), from building level to clusters of buildings (collective concepts) to multi-sectorial integration, thermal networks (THERNET) for heating and cooling, flexibility through Demand Response (DR) in multi energy vector systems, including uncertainties towards robust design and robust control.

The SySi Team, led by prof. Lieve Helsen, has gained significant expertise and international recognition in the field of system integration for performance optimisation of thermal systems. White-box MPC in tertiary buildings is now commercialised through the start-up BUILTWINS. Today The SySi Team consists of 1 professor, 1 innovation manager, 1 post-doctoral researcher and 4 PhD students. In September 2023 the group will be extended with 2 researchers and 1 post-doctoral researcher, and in January 2024 with 3 PhD students and 2 post-doctoral researchers. The research has very close links and is integrated within EnergyVille, a research collaboration between KU Leuven, VITO, imec and UHasselt on sustainable energy and intelligent energy systems.
This PhD position is (together with a full-time post-doctoral researcher) framed in and funded by the Horizon Europe project SEEDS (Cost-effective and replicable RES-integrated electrified heating and cooling systems for improved energy efficiency and demand response), which is an Innovation Action (in the HORIZON-CL5-2023-D4-01-05 call) set up as a collaboration between 27 partners spread all over Europe. This project develops and demonstrates cost-effective, highly replicable and integrated systemic solutions that will significantly speed up the electrification of thermal systems through energy renovation and system smartification in the building sector.

SEEDS unites a multidisciplinary and complementary team of SMEs, LEs, RTOs, and stakeholders that constitute the whole (local) value chain of energy efficiency in buildings and thermal demand electrification, from planning, design, and construction to operation and commissioning. SEEDS is built upon the consortium's vast experience in developing, testing, and valorising decarbonization solutions, supervising real-life demonstrations of building renovation and smartification, and deploying energy flexibility. SEEDS demonstrates replicable heat pump solutions integrated with renewable energy to decarbonize buildings' thermal demand. Addressing that every building is unique and requires tailored solutions to be cost-effective and energy efficient, we develop scalable and generic design and operational optimization methodologies, deploy multiple proven heat pump technologies at scale, and optimally integrate them into the building and broader energy system. SEEDS demonstrates these (up to TRL6-8) in 6 pilot sites (incl. 1 replication site), providing real-world settings spread across the different climate zones and European construction markets. SEEDS is centred around three key themes: cost efficiency through optimization, system integration through holistic design and control, and replicability through configuration modularity and scalable building types. These are addressed in 7 focus areas: 1) Iterative design of the component and integrated system, 2) Secure and interoperable data platforms and IoT, 3) Integrated system optimization for energy efficiency and flexibility, 4) Deploying energy flexibility to enhance grid stability, 5) Replication strategies, exploitation, and business models, 6) Decision making support framework for replication, and 7) Dissemination, communication, and stakeholder outreach. Thanks to the 27 partners' wide-reached field of impact and networks, SEEDS is set out to boost the electrification of thermal demand in buildings.

The PhD position defined here will focus on the Belgian Pilot (De Schipjes) and its replication site (Stijn Streuvelstraat), both heritage neighbourhoods (located in Bruges) that lead the way to electrify historical city centres in Europe. The key innovations, tackled by the team of the PhD student and post-doctoral researcher, assisted by the innovation manager Dr. Glenn Reynders and supervised by Prof. Lieve Helsen, in close collaboration with Sweco Belgium, Builtwins, Mintus, Daikin Europe, will be:
  • Integrated design of a collective hybrid heat pump system based on air-water and ground-water HPs for cost-effective electrified solutions, including comparison STC versus PV + battery versus PVT + battery;
  • Adaptive hydronic scheme for seasonal switch; 
  • Smartification of the heat pumps to facilitate MPC integration;
  • Integrated optimal control and sizing, using white-box MPC, including stress-testing for robust design;
  • Extension of white-box MPC for multi-energy vector districts (including the adaptive hydronic scheme, STC/PV/PVT, long-term behaviour of the borefield, integers, and using different objectives), virtual assessment, demonstration, monitoring and evaluation in the field; 
  • Continuous Commissioning using the white-box model; 
  • Replication of the hybrid concept from De Schipjes Pilot to Stijn Streuvelstraat Pilot; 
  • Contribution to Replication Strategies, Decision Making Support Framework, Communication and Dissemination.


We are looking for a highly motivated, enthusiastic, dynamic, mobile and communicative researcher with a Master of Science degree in Engineering or a related field. The candidate should have a strong background and interest in energy, and especially in (collective) (thermal) energy systems (for residential buildings), (optimal) control (MPC), (physics-based) modelling and optimisation. The candidate starts from insights in the system and physics-based modelling and enriches these approaches by available data.

The candidate is expected to:
  • Be scientifically rigorous, initiative taking, results oriented, loyal
  • Be proficient in English (spoken and written) to allow effective communication, knowledge of Dutch is an asset
  • Be able to work independently, accurately and methodically
  • Be a team player, using the broad network offered
  • Be an active player in the broader team, attending brainstorm sessions, sharing approaches, insights and vision
  • Present research findings at national and international conferences
  • Publish research findings in international top-journals
  • Contribute to the Horizon Europe SEEDS project as one of the main researchers for the novel developments, but also for the related demonstration, replication strategies, communication, dissemination and valorisation tasks
  • Knowledge of Modelica and Python is an asset
  • Attend international project meetings and write project reports
  • Assist in teaching activities through project work and exercise sessions
  • Supervise Master theses

This PhD researcher will be fully funded through the Horizon Europe SEEDS project. The research is to be performed within The SySi Team in close collaboration with the post-doctoral researcher funded by the same project, The SySi Team members working on related topics and the SEEDS project consortium members (3 universities (DTU, KU Leuven, DUTh), 4 RTOs (EMI, Certh, Institut Jozef Stefan, PSACEA), 10 SMEs (Builtwins, Ptherm, Renel, R2M, HOR-BER, CDK, FairC, AInergy, INNO, Enfor), 7 LEs (SIEMENS, Daikin Europe, RINA, Sweco Belgium, Saint-Gobin Hungary, PETROL, Elektro Celje), 1 NPO (Mintus) and 2 MUNs (BP16, Fredericia Kommune)), and in the framework of EnergyVille ( The location for this position will be Leuven (Department of Mechanical Engineering), with the demonstration sites located in Bruges (De Schipjes and Stijn Streuvelstraat).

The successful candidate will receive:
  • Doctoral scholarship, renewable up to four years, and a PhD degree in Engineering if successful
  • A highly specialized doctoral training, making the candidate expert in optimal clean hybrid energy systems for clusters of buildings
  • An extensive international network of universities, companies and associations to work with
  • Multiple benefits (health insurance, access to university infrastructure and sports facilities, etc.) 
  • A very competitive salary, including social security
  • The opportunity to participate in international research collaborations and international conferences
  • A very inspiring research climate where each team member can learn, reflect, fail, orientate, engage, feel connected, dive deep, dream, be challenged, grow, innovate, be proud, celebrate novel results and awards in interaction with each other but always starting from own strengths
  • The city of Leuven, just 20 km east of Brussels, the heart of Europe, offers a stimulating, young and multicultural working environment