Mechanical Engineer

About Us

Exergy3 is a Scottish cleantech company developing and commercialising a high-temperature Thermal Energy Storage (TES) system for industrial decarbonisation. Our technology converts surplus electricity into stored heat, delivered as process steam or hot air directly into industrial plant, displacing natural gas and reducing industrial carbon emissions without requiring customers to redesign their processes.

More than 50% of global CO₂ emissions arise from industrial heat processes. Exergy3 provides a reliable, cost-effective and scalable solution: one that enables industry to decarbonise without compromising operational performance.

Having recently secured investment, Exergy3 is transitioning from technology development to commercial deployment. We aim to deliver a commercially-ready product, establish the partner and supplier ecosystem required to scale delivery.

SALARY RANGE: £35,000 - £45,000

CLOSING DATE: 25 August 2026

The Role

We are looking for a versatile Mechanical Engineer to join our growing, agile team in Edinburgh. You will play a critical role in the design, development, and implementation of cutting- edge thermal energy storage systems that span mechanical, fluid, and electrical domains. This is a multidisciplinary, hands-on role that combines high-level design work with practical engineering delivery.

The ideal candidate will thrive in a dynamic, fast-growing environment, possess excellent problem-solving skills, and show initiative in scaling design and documentation processes as we move from prototyping to production and deployment. They will be comfortable moving between detailed design, supplier discussions, prototype assembly, testing and documentation.

Key Responsibilities

In this role you will work closely with colleagues within the wider engineering team, technicians, subcontractors, and health and safety consultants to deliver robust, high-performing systems. Some travel to project sites may be required from time-to-time.

Design & Engineering

• Detailed engineering design integrating mechanical, fluid, and electrical components, including tolerance analysis and management.
• CAD and drawing management: reviewing, organising, issuing, and maintaining up-to-date design documentation.
• Creation and maintenance of bills of materials.
• Develop and maintain system-level designs across mechanical, thermofluidic and electrical interfaces.
• Build, modify and troubleshoot prototypes in collaboration with workshop technicians.
• Development of instruction manuals, assembly guides and maintenance manuals.
• Creation and implementation of design registers and other structured design documentation tools.
• Cost-reduction engineering: evaluating materials, manufacturing methods, and assembly processes.
• Development and execution of system experimentation and test schedules.

Project & Change Management

• Distributing, tracking, and delivering engineering work packages to meet deadlines.
• Coordination with subcontractors and technicians to ensure proper and timely documentation and delivery.
• Provide technical input to risk assessments, method statements, design risk reviews and safe systems of work.
• Supporting and documenting testing activities of workshop-built prototypes.

Supplier, Procurement & Supply Chain

• Technical management of existing and new suppliers to ensure specification compliance and delivery.
• Procurement of components and systems: from specification through purchase and delivery.
• Support for supply chain resilience: alternative material and vendor identification.
• Develop clear and rigorous specifications, ensuring that supplier deliverables align with defined technical and quality requirements.

Desirable Additional Skills

• Electro-mechanical integration and specification of electrical components.
• Control system hardware and software adaptation experience.
• Ability to inherit and modify control software for new applications.
• Thermofluidic modelling, including ability to interpret CFD or FEA results and work effectively with internal or external specialists.
• First-principles-based modelling of thermal systems.
• Manufacturing engineering experience with design–manufacture interaction.
• Development of new technologies with potential for intellectual property protection.
• Sensor integration experience (e.g., pressure, temperature).
• Design risk registers for installation and operational phases.
• Experience with high-temperature systems.
• Familiarity with engineering design processes required for achieving formal product certifications, including documentation, testing, and compliance audits.

Why Join Exergy3?

• Be part of a dynamic and innovative company at the forefront of clean energy technology.
• Play a pivotal role in driving the growth and success of Exergy3.
• Opportunities for professional growth and development.
• Contribute to a sustainable future by promoting clean heat solutions.
• Opportunity to shape the design processes, documentation standards, and engineering practices at a critical growth stage.
• Be a key contributor in turning emerging technologies into commercially viable products.
• Work at the intersection of academic innovation and industrial impact, helping scale clean heat solutions across Europe.

Must have:

• Bachelor’s or Master’s degree in engineering or a related discipline.
• At least two years of professional engineering experience following graduation.
• Strong record of cross-disciplinary collaboration (electrical, mechanical design, manufacturing).
• Practical, hands-on engineering experience, including building, modifying or troubleshooting hardware.
• Excellent verbal and written communication skills for technical documentation and supplier liaison.
• Right to work in the UK.

• Competitive salary 
• Stock options
• 34 days annual leave (UK) inc. public holidays
• Company pension
• Hybrid working - 2-3 days in office
• 35 hour working week
• Compressed hours
• Up to 15 days of remote work from abroad each year

OUR GUIDING PRINCIPLES

If these principles resonate with you, we look forward to receiving your application.

Respect for the task

What we do is challenging! What we do is significant—for humanity, for our customers, and for one another. Someone has to do it, and we embrace the challenge.

Speak plainly

No sugar-coating, no dodging the issue. We speak openly, share the full picture, and collaborate based on genuine trust. Honesty isn’t just a value; it is the foundation for better decisions.

Take ownership

We don’t wait to be told what to do. We identify what needs to be done and take personal responsibility for seeing it through to completion.

Efficient and precise

We don’t get distracted. We focus on the details that matter. We channel our energy into critical tasks to quickly turn ambitions into results.

Mistakes happen!

Occasional mistakes are normal. When they occur, we learn from them together and move forward.

Enjoy the work

We take our work seriously, but we don’t take ourselves too seriously. We celebrate successes and support one another—because great teams are built on trust and genuine care.

Exergy3 is an equal opportunity employer. We value diversity and are committed to creating an inclusive environment for all employees.