Stefan Lechner

Prof. Dr.-Ing. Stefan Lechner has been full Professor of Energy Economics and Energy Systems at the Technical University of Central Hesse (THM), Giessen, since March 2015. He is affiliated with the Department of Mechanical Engineering and Energy Technology and the Institute THESA – Institute of Thermodynamics, Energy Process Engineering and Systems Analysis. Additionally, he leads the Laboratory for Energy Economics and is a core member of the Competence Center for Energy Technology and Energy Management (etem.THM).

Education & Career

• Dr.-Ing., Brandenburg University of Technology (BTU) Cottbus, 2012 – Dissertation on steam-fluidized-bed drying of lignite.
• Dipl.-Ing. (FH) Mechanical Engineering, Georg Agricola University of Applied Sciences Bochum, 2002 – specialising in Future Energies.
• Supplementary doctoral studies & economics coursework at BTU Cottbus and FernUniversität Hagen.
• Professional experience at Vattenfall (plant management, power-plant planning & R&D) and Kreisel Umwelttechnik (Head of Development) before entering academia.

Research Interests

Prof. Lechner’s work centres on the techno-economic analysis and optimisation of energy systems in transition. Core themes include renewable energy integration, thermal energy storage (particularly Carnot batteries using ceramic high-temperature stores), sector coupling between electricity, heat and mobility, and 5th-generation cold district-heating networks (5GDHC). Methodologically, he combines experimental thermal engineering with open-source simulation frameworks, agent-based demand modelling, and electricity-market modelling.

Recent activities expand into waste-heat recovery from data centres and transcritical CO₂ heat-pump systems for low-temperature district heating, always targeting cost-effective, grid-friendly and sustainable solutions.

Publication Trends

Between 2017 and 2024 his output highlights a clear evolution from fundamental studies on pressurized steam fluidized-bed drying and lignite heat-transfer toward system-level analyses of storage-based sector coupling. A dominant cluster addresses Carnot batteries, covering high-temperature storage materials, gas-turbine re-conversion concepts, and demonstration results. Parallel streams examine GIS-based rooftop PV potential, agent-based settlement energy-demand modelling, and regulatory frameworks for cross-sector energy markets.

Scientific Awards & Honours

No specific awards are mentioned in the provided material.

Research Funding & Teams

Prof. Lechner has secured and coordinates projects worth > €10 million (THM share ≈ €6.5 million) funded by BMBF, BMWK/BMWi, Hessian ministries (HMWK, HMWEVW), WI-Bank and ERDF:

• LOEWE 3 DUWä (2025-2027) – transcritical CO₂ dual-use heat pumps for cold district heating.
• EnEff:Stadt FlexQuartier2 (2023-2027) – hybrid storage optimisation in Giessen’s Philosophenhöhe district.
• KNW-Plus (2022-2023) – design & online tool for cold local heating networks.
• Innovative waste-heat use from data centres (2022-2023).
• FlexQuartier Gießen (2018-2023) – integrated hybrid storage & sector coupling in a new-build district.
• Kommun:E (2018-2022) – municipal energy-supply transformation under Germany’s Energiewende.
• High-T-Stor (2017-2019) – cross-sector high-temperature storage for renewable balancing.
• FES (2019-2021) – Research Center for Energy Storage and Sector Coupling.

These projects involve interdisciplinary consortia including municipalities, grid operators, SMEs, and research partners across Germany.

Teaching & Academic Leadership

He lectures in Energy Economics and Sector Coupling, Energy Markets, Heat Transfer, Renewable Energy Technology and Energy System Analysis. He also serves as Programme Manager for the part-time continuing-education M.Sc. Energy Efficiency Management (StudiumPlus, Wetzlar) and contributes to advanced master’s courses on energy law and thermodynamics.