Thermal Energy Storage Engineer (all genders)

Starting anytime

Job Description: We are seeking a highly skilled and motivated Thermal Energy Storage Engineer to spearhead the development of our thermal storages as subsystems of our LAES. The successful candidate will be responsible for all activities around development of both hot and thermal energy storages from conceptualizing, to modeling, simulating, designing, analysis, integrating, and construction. You will work in close interaction with, CTO, VP Engineering and other engineers from interfacing disciplines with a focus on achieving our development and scale-up milestones. We expect you to learn fast and grow with the company as we expand the team, activities, and facilities. The ability to self-organize, critically prioritize, and being proactive and team-oriented are key attributes.

Who are we?

phelas is developing the next generation of Liquid Air Energy Storage (LAES); a newly patented containerized, modularized system balancing efficiency, cost, and customers & market needs. Our approach is a unique, cost-effective thermo-mechanical system with a bright future. We are rigorous problem solvers, believe that ideas can come from anyone at any level, and are motivated to improve the well-being of our planet. The best and brightest minds should work on the hardest problems. Come join us to make 100% renewable electricity a “no-brainer” everywhere on this planet!

What will you do?

  • Take responsibility and lead for all the aspects related to thermal storage development, selection, and realization, from design, detail engineering, analysis, all the way to implementation into the system.
  • Detailed sizing, static, dynamic, and operation modes analysis of thermal (hot and cold) energy storages.
  • Investigating the existing established thermal storage technologies, and exploring how they could be potentially modified, integrated and merged into our LAES.
  • Define models, test plans and metrics to support subsystem tests to validate methods and design
  • Optimizing the design and performance of the thermal storages based on the requirements of the system and its peripheries.
  • Work closely together with engineers from interfacing disciplines to develop and establish efficient designs, and to ensure a timely delivery of the integrated energy storage system
  • Verify structural integrity by performing analysis using analytical methods, finite element models/simulations, and other analysis tools throughout the product life-cycle to develop the structural environment, characteristics, and performance.
  • Evaluate the mechanical strains and stresses due to mechanical and thermal loads.
  • Coordinate and communicate the specifications internally and externally, including communication with EPC contractors, equipment vendors, and other partners.
  • Coordinate and supervise testing and pre-shipment inspection of critical equipment in the suppliers manufacturing facilities.
  • Provide support for troubleshooting of thermal storages at various facility sites.

Who are you?


  • Bachelor degree in Mechanical Engineering, Chemical Engineering, Thermal Engineering or similar fields.
  • Extensive professional experience in a similar position with a proven track record in developing, implementing, and integrating thermal storages, preferably focused on cryogenic thermal storages.
  • Extensive experience in heat transfer analysis and thermal management, preferably in cryogenics and/or refrigeration industries.
  • In-depth knowledge of fluid dynamics, conjugate heat transfer, thermal-mechanical design principles and their prediction with state-of-the-art CFD methods and FEM analysis.
  • Ability to generate and review detailed analysis reports, and excellent documentation skills
  • Excellent problem-solving skills and ability to work in a fast-paced environment with ambiguity.
  • Solution oriented, passion for developing and implementing solutions.
  • Knowledge in engineering best practices, creating requirements & specifications, developing cost estimates and project schedules.
  • High level of self-reliance with the ability to work in a team, as well as autonomously
  • Strong motivation to help build and shape your organization, structures and processes
  • Fluent English language skills are essential.

Nice-to-haves & Big pluses

  • Master’s degree or PhD in Mechanical Engineering, Chemical Engineering, Thermal Engineering or similar fields.
  • Professional experience performing structural analysis and FEM of gravel sands, metals, and plastic structure.
  • Proficiency with CAD
  • Familiarity with safety protocols and process HAZOP
  • Experience in engineering project management, and driving a complex project through completion.
  • Ability to lead multiple projects simultaneously
  • German language skills is a plus.

If you are interested in this position but your previous experience does not perfectly match every point in the job description, we encourage you to apply anyway!

What we offer:

  • phelas is a place to grow ideas and strive as a team. We can confidently say, best ideas win!
  • Currently 10 people with 7 nationalities, this is a place to shape our own work culture and serve global markets.
  • Full-time employees participate in value increase of the company (employee stock programme)
  • Having started at TUM (Technical University of Munich), we are connected well in the ecosystem and are surrounded with brightest minds.
  • Speaking of Munich, we are based in a top10 worth-to-live-in cities in Europe.
  • Flexible work hours. At phelas, we care about results and achieving our goals, not about being present 9-5.
  • Hybrid workplace / home-office: As much as we enjoy on-site collaboration and working on hardware, we also know that diving deep into tasks is easier when undistracted.
  • Transparent communication: This is the foundation of phelas’ positive work-environment. We share highs and lows and ensure effective flow of information.

Who are you?

Contact and tell us!

phelas is an equal-opportunity employer. We are committed to creating a diverse and inclusive environment for all employees and welcome applications from all qualified candidates, regardless of roots, colour, religion, gender, sexual orientation, neurodivergency, national origin, age, disability, or any other protected characteristic.