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About Us

UEST is a strategic partnership of the HOT Energy Group, the ILF Group, RED Drilling & Services and CAC Engineering.  The consortium fuses the individual partners’ decades of project management and broad expertise in underground storage technologies.  UEST’s Centre of Excellence empowers leaders by providing strategic advice and delivering high-end solutions for natural gas, carbon dioxide, hydrogen storage and geothermal energy.  UEST’s global footprint is supported by offices in Austria (headquarters) and Germany, and a network of alliance and representative offices worldwide.




Billion Cubic Metres of Storage Capacity



Storage Surface Facilities Developments – from Concept to Operation

Planned & Drilled


Energy Storage Wells



Metres Storage Reservoir



Industrial Plants



Storage and Production Stations



Years of Combined Corporate Experience

Our Key Team


Dr Diethard Kratzer


Diethard Kratzer combines 30+ years of experience in consulting and R&D management. He is founder and CEO of HOT Engineering and heading the HOT Energy Group.


Dr Leonhard Ganzer


Leonhard Ganzer is head of the Institute of Subsurface Energy Systems at Technical University Clausthal in Germany focusing on underground hydrogen storage, CO2 injection, carbon capture and storage (CCS) or usage (CCU). He is experienced in leading roles of R&D projects and technology development for underground storage of hydrogen or CO2. He also acts as expert for the Austrian mining authority for underground gas storage projects.


Dr Andreas Harrer


Andreas Harrer is Head of Consulting Services for the HOT Energy Group. With almost 20 years’ in-depth experience in reservoir engineering and simulation, Andreas has conducted and supervised the modelling and planning of many underground gas storage facilities.

Chandrasekhar Ramakrishnan / The ILF Group

Dr Chandrasekhar Ramakrishnan

Project Management & Facilities

Chandrasekhar Ramakrishnan is Managing Director at ILF Consulting Engineers Austria GmbH. His background comprises nearly 20 years of experience in the international oil & gas industry. He has managed, led and supervised numerous on- and off-shore projects globally, and he is also an experienced HAZOP Chairman. His recent focus of activities is following all the trends of circular economy, including projects/developments in green hydrogen and ammonia, carbon capture and utilisation, e-fuels and recycling of plastics and batteries. Since 2021 he has been also acting as Global Downstream Advisor to the UAE office of ILF, supporting Downstream capability build-up and following various business development opportunities worldwide.

Christian Pataky / The ILF Group

DI Christian Pataky

Project Management & Facilities

Christian Pataky is heading the Business Unit Oil, Gas & Industrial within ILF Consulting Engineers Austria GmbH. In this position Christian is responsible for the business development and execution of Project Management and Engineering for projects within this business area. Before taking over this position in 2016, he was Project and Engineering Manager in all project phases for Upstream & Midstream projects locally and abroad. Christian holds an MSc in Industrial Engineering from the Technical University of Vienna. He is eager to cope with the challenges and requirements of the energy transition and the related implementation of “new technology” projects.

Buzatoiu Bogdan / The ILF Group

Bogdan Buzatoiu


Bogdan Buzatoiu is a Senior Expert (Process) for Upstream with more than 30 years of experience and Lead Engineer for oil and gas surface facilities and Renewable Energy. As a member of the Clean Hydrogen Alliance, he is involved in Green H2 production technologies and projects. Bogdan has relevant expertise in flow assurance, natural gas underground storage facilities, CCUS and related processes, in renewable energy development, energy recovery from abandoned oil wells and also in laboratory analysis for oil & gas fluids, including PVT analysis, production and field chemistry.

Mr Heimo Heinzle / © Steve Haider

DI Heimo Heinzle

Drilling & Well Engineering

Heimo Heinzle is Technical Director at RED Drilling & Services. He is a petroleum engineer with more than 20 years of experience and has held a variety of positions as drilling engineer and engineering manager in Austria and abroad.

Rudolf Loisel

Rudolf Loisel


Rudolf Loisel is a production engineer with more than 30 years of experience in the commissioning, operation and optimization of natural gas drying and underground gas storage facilities. As a long-time employee of RAG Austria, one of the leading European storage operators, he was responsible for the production and maintenance of gas fields as well as the operation of natural gas storage facilities. Being former supervisor for the Haidach gas storage facility, he is well familiar with project support, commissioning and operation of process engineering systems in the oil and gas industry.

Mr Leopold Hauser

Leopold Hauser


Leopold Hauser is a mechanical engineer with almost 30 years of experience in the development, execution and operation of Underground Gas Storages Surface Facilities – from concept development up to operation. As Engineering Manager of RAG Austria, one of the leading European storage operators, Leopold was serving the development of more than 10 gas storage surface facilities.

Joerg Engelmann

DI Joerg Engelmann

Project Management & Surface

Joerg Engelmann is CEO at CAC Engineering with more than 30 years of experience in the management of Large Industrial Projects including the implementation of surface facilities for natural gas storages.
Since 2004 he has been leading the CAC Group of Companies.

Stephan Canzler

Stephan Canzler

Process & Surface

Stephan Canzler is Senior Process Engineer and acting as Product Manager and Lead Engineer for projects of natural gas surface facilities and Compressor Stations. Since more than 30 years he has been responsible for the development of a customized process technology and the later commissioning of the respective facility.


Dr Jonas Wegner


Jonas Wegner is Chief Technical Officer with HOT Microfluidics and Head of Laboratory Services for the HOT Energy Group. He has been lead developer for the application of microfluidic technologies for the visualisation of underground flow and transport processes as well as for developing innovative solutions for the measurement of thermodynamic properties of hydrogen and hydrogen mixtures, including a patent-pending diffusion setup. Jonas is reservoir engineer with more than 10 years of experience focusing on fluid flow in porous media, enhanced recovery and numerical modelling and simulation. He authored and co-authored many scientific papers and is instructor for the industry and academia.

Dr Birger Hagemann

Dr Birger Hagemann

Simulation Research

Birger Hagemann is senior scientist at the Institute of Subsurface Energy Systems, Clausthal University of Technology. He has been working on several scientific and industrial projects related to the underground storage of hydrogen, carbon dioxide and natural gas and underground bio-methanation. His emphasis is the numerical modeling and simulation of gas storage operations considering microbial interactions.


The HOT Energy Group (HOT) is a leading subsurface engineering provider for production, injection and storage operations. Its vast subsurface experience stems from more than 35 years of characterising, modelling and simulating complex oil, gas & condensate reservoirs, underground gas storage (UGS) facilities and aquifers. During this time, HOT has proudly supported its customers in developing and extending underground gas storage facilities and operations to cope with the increasing, yet fluctuating, seasonal energy demand.

“While our core business originated in the upstream oil and gas industry, our innovations, technologies and solutions are scalable, expandable and portable across other energy systems and industries, and have made us a trusted advisor and partner for energy transition and innovative and sustainable energy solutions and subsurface energy systems.”

Dr Diethard Kratzer, Founder & CEO


“ILF combines local presence and international expertise to sustainably serve clients’ needs.”

Klaus Lässer, CEO

The ILF Group (ILF) is a leading international engineering and consulting group that supports its clients to successfully identify, prepare and execute technically challenging energy, industrial and infrastructure projects. With over 2,600 highly qualified employees in more than 45 offices across five continents, the companies of the ILF Group have a strong regional presence. This enables ILF to interact with clients and project parties at any time and any place.


RED Drilling & Services GmbH (former RAG Energy Drilling GmbH) was established in 2014 as a 100% subsidiary of a long-established Austrian exploration, production and gas storage company with over 80 years of experience. The core business is the planning, implementation and maintenance of oil and gas exploration and production wells, gas storage and geothermal wells, as well as the plug and abandonment of old wells. Besides subsurface and surface engineering services RED is also operating its own drilling and workover rigs.

“Being a former operator, RED understands the needs of its clients and combines planning and operations experience of more than 1.200 projects with best in class performance while achieving highest quality and safety standards.”


About CAC Engineering GmbH (CAC)

“By considering our long term experiences and technological competencies, CAC is combining the flexibility of a medium-sized privately owned enterprise with project related skills and tools of a large Industrial Plant Manufacturer.”

DI Joerg Engelmann, CEO & Shareholder

CAC Engineering GmbH (CAC) is a renowned plant engineering company with more than 25 years’ experience in the planning, implementation and commissioning of gas plants and also surface facilities for natural gas underground storages by providing the whole range of engineering services from its own sources.
With around 400 employees, 280 at the company headquarters in Chemnitz, CAC has built more than 500 industrial plants worldwide.

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