At Supercritical, we’re not just building cutting-edge technology—we’re shaping the future of clean energy. Working here means being part of a fast-moving, deeply collaborative team that thrives on innovation, curiosity, and impact. We operate with trust and transparency, valuing diverse perspectives that drive better solutions. Our culture is dynamic and ambitious, but also supportive—everyone has a voice, and great ideas come from everywhere. Expect to work alongside passionate experts who challenge the status quo, celebrate wins together, and push boundaries to make green hydrogen affordable and accessible. 

Supercritical is looking for a dynamic, passionate and driven Process Engineer to join our product development team. We are looking for someone to help us shape our system design to meet our target KPIs on safety, performance, efficiency and cost.

You will be passionate about diving into complex problems to pioneer innovative and novel solutions for our challenging operating conditions, while asking “How can we do this better, safely?”, with a focus on bringing our proprietary electrolyser and associated balance of plant through increasing scales, from demonstrator to pilot and commercial scales.  You will work directly with our Head of System and Senior Process Engineers to design and deploy larger scales within our test environments and partner sites.  You will also support the Technology team who focus on electrolytic testing at larger and larger scales within our test environments and partner sites.  

Whether it’s solving complex engineering problems, securing partnerships, or scaling our breakthrough technology, every role at Supercritical is mission-driven. If you’re looking for a place where your work genuinely matters, where you can grow, and where you’ll be empowered to take ownership, you’ll feel at home here.

• Execute process engineering design activities in a timely and cost-effective manner.
• Collaborate with our subcontractors and vendors to enable our goals of commercial pilot plant deployment by 2027.
• Flowsheet development (PFDs), detailed design and mass and energy balance calculations.
• Process control and system design (Cause and effect, T&As, P&IDs).
• Calculation development for design and sizing of equipment, valves and instrumentation.
• Creating equipment and instrument specifications, and supporting the procurement process.
• Hazard identification and risk management (HAZID, HAZOP and LOPA).
• Support site/plant based activities - commissioning, performance testing and troubleshooting
• To work with Supercritical’s technology team, to support our lab-scale testing and scale-up, working to minimise hazard and risk. 
• Partner and vendor liaison and negotiation.

Ideally, you’re passionate about clean energy and eager to bring innovative ideas to life in a collaborative and inclusive environment. You will:

• Be a self-starter and proactively identify problems and pursue solutions.
• Have a master's degree or above in Chemical / Process Engineering.
• Have relevant experience within the Hydrogen, Chemical, Nuclear, or related regulated industries.
• Be comfortable in process engineering design from first principles.
• Have 3 years professional experience with process design.
• Contribute to an empowering culture around safety in our team.
• Have strong communication and organisational skills, attention to detail and enjoy working in a team environment. 
• Be committed to inherent safe design and to the minimisation of risk. 

Desirable

• Knowledge of water electrolysis, hydrogen, its applications and its uses.
• Design experience in hydrogen and oxygen.
• Design experience in supercritical water.
• Have experience in process modelling software such as Aspen, HYSYS, PRO II or Unisim.
• Experience in scaling up designs.
• Chartered engineer status.
• CFD/modelling experience.
  

Supercritical is looking for an experienced process engineering professional with technical safety competence to join our Product team as a Senior Process Safety Engineer. We are looking for someone to help us shape our system design to meet our target KPIs on safety, performance, efficiency and cost.

You will be passionate about diving into complex problems to pioneer innovative and novel solutions for our challenging operating conditions, while asking “How can we do this better, safely?”, and build an empowering culture around safety in the team. You will bring your skills and curiosity to the team, focussing on delivering our proprietary reactor design and associated balance of plant through increasing scales, from demonstrator to pilot to commercial product. You will also support the Technology team who focus on electrolytic testing at larger and larger scales within our test environments and partner sites.  

You will join an exciting and fast moving company that is intent on disrupting the energy industry and enabling a net zero future.

• Manage the process safety lifecycle of demonstrator test rigs and customer pilots from concept, design through to operations.
• Develop and own safety deliverables (e.g. safety basis, Failure Mode and Effects Analysis (FMEA), etc.).
• Work with Supercritical’s technology team, to support our lab-scale testing and scale-up, working to minimise hazard and risk. 
• Ensure readiness for HAZOP & HAZID with external partners, and leading team workshops for hazard identification and risk management,
• Develop and own engineering deliverables across the design lifecycle (e.g. PFDs, equipment sizing, HMBs, P&IDs, Commissioning plans, SOPs, etc.).
• Deliver process engineering design activities in a timely and cost-effective manner.
• Carry out engineering calculations to support system design (e.g. PSV sizing, Safety Time calculations, ventilation rates, SIL validation, etc.).
• Collaborate with our partners, subcontractors and vendors to enable our goals of reaching pilot scale by 2026.
• Project manage the implementation of system development work packages under your accountability.
• Champion best practices in safety within the Product team, e.g. implementing  Inherently Safer Design (ISD) principles.
• Guide the implementation of zoning hazardous areas for explosive atmospheres (ATEX / DSEAR), control of hazardous substances (COSHH).

Ideally, you’re passionate about clean energy and eager to bring innovative ideas to life in a collaborative and inclusive environment. You will:

• Be a self-starter and proactively identify problems and pursue solutions.
• Have a masters degree or above in Chemical / Process Engineering.
• Have relevant experience within the Hydrogen, Chemical, Nuclear, or related regulated industries.
• Have demonstrable professional experience in a technical safety specific role
• Have demonstrable professional experience across the project development lifecycle.
• Have experience of working with high pressure/high temperature systems and flammable gases.
• Be adept in process engineering design from first principles.
• Have experience in employing PHA techniques and Process Safety Management,
• Have knowledge of applicable safety standards in high hazard industries (e.g. ATEX)
• Be experienced in safety monitoring equipment, instrumentation, process control,
• Have strong communication and organisational skills, attention to detail and enjoy working in a team environment. 
• Be committed to inherent safe design and to the minimisation of risk. 

Desirable

• Knowledge of water electrolysis, hydrogen, its applications and its uses.
• Chartered Engineer with a Professional Engineering Institution.
• Have knowledge of hydrogen industry standards.
• Experience of Layers Of Protection Analysis (LOPA).
• Experience of modelling tools & calculations for dispersion & explosion, e.g. PHAST, FLACS.
• Experience of design simulation tools such as Aspen Plus, Hysys or Unisim.

Supercritical is seeking an experienced and innovative Senior Electrical Engineer to join our Technology team. You will play a critical role in bringing Supercritical’s groundbreaking electrolyser technology to market by optimising its electrical architecture and designing robust, high-performance systems. 

Taking a leading authority in electrical engineering designing Supercritical’s core product, the electrolyser, you will work in a diverse and multidisciplinary team on an exciting development road to commercialisation.

We are looking for a passionate problem-solver who thrives in tackling complex challenges and has a strong commitment to safety, performance, and innovation. You will work at the forefront of the green hydrogen revolution, enabling a sustainable future by decarbonising hard-to-abate industrial sectors.

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• Design and develop Supercritical’s modular electrolyser from its existing prototype through to pilot and productionisation.
• Be the in-house design authority for the electrical architecture, leading on the electrical system design calculations and modelling electrical losses across the cell, module and system.
• Design, calculate, and model the modular electrical system to optimise for efficiency, interfacing with engineers and scientists of all discliplines in the wider design team
• Lead the scaling of the electrical design to a multi-module pilot and commercial plant from conception to execution.
• Lead electrical test and validation working closely with the technology, process, safety and mechanical teams.
• Qualify installations and commission systems. Troubleshoot  real-world challenges and diagnose the root cause of issues.
• Represent electrical discipline technical input for projects and/or proposals; including preparation, checking and/or approval of engineering documentation, specifications, BoMs and work packs for equipment and materials.
• Create and maintain system documentation such as Interface Control Documents, System Descriptions, Requirements, etc.
• Support the C&I function in scoping, identifying and deploying optimal electrical instrumentation.
• Ensure all applicable national and international codes of practice, legislation and company/client standards and procedures are complied with.
• Offer expert insight in system design reviews and in safety reviews such as HAZOPs and FMEAs.
• Manage relationships with external partners and contractors ensuring accurate and timely deliverables.
• Support future commercial engagements through stakeholder engagement, data analysis, and techno-economic modelling.

Ideally, you will:

• Be passionate about a net zero environment, excited by innovation and proactive in your pursuit of it.
• Be Degree qualified (or equivalent) in relevant electrical engineering discipline
• Have 6+ years of professional experience in electrical engineering design roles.
• Have good working knowledge of design practices and installation requirements of the discipline across a range of industries with extensive UK legislation and standards and HSE requirements
• Have experience with IEC regulations & all relevant UK standards and specifications.
• Have experience on testing, checking and commissioning of systems, wiring diagrams, working closely with the control side
• Have knowledge of LV isolations, energisation and commissioning requirements.
• Have experience in the requirements for CE marking of plant and equipment and the Low Voltage Directive and Machinery Directive.
• Be a self starter and proactively identify problems and pursue solutions.
• Have excellent communication skills.
• Have strong organisational skills, attention to detail and enjoy working in a team environment.
• Be able to manage multiple projects simultaneously without losing sight of the long term goal.

Supercritical is looking for a finance manager to play a critical role in maintaining order within our fully digital financial systems. We are looking for a detail-oriented colleague to ensure we have a solid foundation for our day-to-day purchasing, financial management, and financial reporting for our grant funding.

With this foundation in place, you will help us build robust financial operations that allow Supercritical to gain a deep understanding of its financial position within the green hydrogen market, make sound commercial decisions that support the growth of the the product and contribute to our mission of scaling green hydrogen and develop financial models and analyses to evaluate new opportunities and support strategic decision-making.

• Ensuring compliance with required accounting practices
  
  • Preparation of monthly and annual financial documents
  • Researching and complying with legal requirements as they pertain to the company's operations and financial activities
• Improving and refining financial operations of a fast-growing organisation
  
  • Producing month end, accounts reconciliations, expenses and accruals and management accounts
  • Creating, maintain and administer company budgets
  • Managing profit and loss statements and balance sheets and support cash flow reporting and tracking
  • Recording financial transactions in format for grant compliance
• Financial administration of the company
  
  • Payroll, pension and Employees travel & expense reimbursement
  • Conduct reconciliation of the company's bank accounts and credit card activities
  • Preparing purchase orders in accordance with requests for materials
  • Perform all activities related to the accounts payable function: including reviewing, coding, and administering payments
  • Preparing payments file each week for supplier goods and services
  • Preparing Quarterly VAT returns (Xero)

Ideally, you will:

• Be a competent and experienced user of Xero accounting software
• Have experience using Google Sheets and have generally strong IT skills
• Have bookkeeping or accounting qualifications (AAT/ ACA, CIMA, ACCA, or equivalent)
• Bring a broad background and track record in the accurate operation and performance of bookkeeping and basic management accounting functions
• Maintain strong team working and interpersonal skills, with the ability to be flexible and adaptable within the environment of a small team
• Be a methodical process-driven person, with passion for accuracy and excellence
• Be a proactive, self-motivated individual capable of working on their own initiative in a constantly changing and pressurised environment and fast-developing company
• Able to identify improvement opportunities, suggest improvements and action change

Supercritical is looking for a senior electrochemist that will enhance our R&D team and move us towards our goals of scaling our cells and modules through advancing our core understanding of the electrochemistry at our novel operating conditions. 

You will join an exciting and fast moving company that is intent on disrupting the energy industry and enabling a net zero future.

• Characterise a wide range of metal electrodes for hydrogen evolution and oxygen evolution reactions.
• Investigate methods to increase the performance and durability of electrodes.
• Investigate deposition methods of catalyst nanoparticles onto the electrode surface.
• Investigate corrosion tolerance of materials and develop corrosion-resistant coatings.
• Assist the CTO with design and fabrication of electrolyser cells and modules.
• Be responsible for designing experiments, pioneering new test protocols and standardising operating procedures.
• Procurement and management of reagents and electrochemical equipment/consumables.
• Reporting outputs of research to the CTO.

Ideally, you will:

• Be passionate about a net zero environment, excited by innovation and proactive in your pursuit of it.
• Have a PhD or significant industrial experience in electrochemistry or a related field.
• Have a strong material science background, ideally specialised with metal alloys and multi-metal oxides.
• Experience of performing cyclic voltammetry, chronoamperometry, chronopotentiometry and electrochemical impedance spectroscopy (EIS) measurements.  Competent at analysing and disseminating results to non-electrochemists.
• Perform EIS data analysis and equivalent circuit fittings and distribution of relaxation times (DRT) analysis , draw conclusions from experimental results and present them comfortably.
• Have experience with surface area analysis techniques.
• Demonstrate strong problem solving skills.
• Have outstanding communication skills, both written and speaking.
• Be proactive and self-motivated, taking initiative to drive towards company goals.

Desirable

• Multiphysics/Electrochemical modelling experience
• Corrosion chemistry experience
• Experience of working with high pressure/high temperature systems
• Density functional theory (DFT) modelling of alloys