Staff Mechanical Engineer - Thermals, BESS

In this role you will own the thermal architecture and cooling strategy for utility-scale BESS platforms, guiding designs from concept to deployment. You will collaborate across inverter, mechanical, electrical, controls, safety, and manufacturing teams to deliver safe, reliable, and cost-effective cooling solutions for harsh outdoor environments. Your work will shape production-ready designs that meet safety and compliance standards while optimizing CAPEX and OPEX. This is a hands-on, leadership-heavy role with a clear impact on system reliability and safety. You will contribute to a mission of delivering scalable, sustainable energy storage technology.

• bonus eligibility
• equity
• benefits

• Lead thermal architecture, cooling strategy, and safety design for cabinet-level and containerized BESS platforms through production and deployment
• Design varied thermal systems (chiller-based, liquid-cooled, air-cooled, hybrid) for power electronics
• Apply first-principles thermal engineering and perform system-level and detailed CFD analyses for production-ready designs
• Lead arcing analysis and containment design including sensors, venting, relief mechanisms, and mitigation strategies
• Drive DFMEA and root-cause analysis with actions from test data and field feedback
• Support supplier selection and design reviews balancing performance, reliability, manufacturability, and cost
• Support certification efforts and AHJ interactions across global safety standards
• Provide technical guidance and mentor junior engineers

• 8+ years in mechanical or thermal engineering with utility-scale BESS thermal experience
• Proficiency in thermal/CFD simulations (Icepak, Fluent, COMSOL, FLACS) and producing production-ready designs
• Experience with NFPA 68/69 and NFPA 855, UL 9540/9540A, IEC standards and certification processes
• Arcing analysis and containment design with sensors, venting, pressure-relief, and mitigation strategies
• System-level understanding of PCS architectures, battery rooms, and thermal coordination with BMS/EMS
• Ability to design for harsh environments (high ambient, high altitude, corrosive) and long-duration storage
• DFMEA leadership and corrective-action experience
• Vendor engagement and technical design reviews
• Technical leadership and mentorship capabilities

• leadership
• cross-functional collaboration
• communication
• thermal architecture
• CFD analysis
• arcing analysis