Senior Staff Mechanical Engineer — Thermals, BESS

Enphase Energy is a global energy technology company and leading provider of solar, battery, and electric vehicle charging products. Founded in 2006, Enphase transformed the solar industry with our revolutionary microinverter technology, which turns sunlight into a safe, reliable, resilient, and scalable source of energy to power our lives. Today, the Enphase Energy System helps people make, use, save, and sell their own power. Enphase is also one of the fastest growing and innovative clean energy companies in the world, with approximately 80 million products installed across more than 160 countries.  
 
We are building teams that are designing, developing, and manufacturing next-generation energy technologies and our work environment is fast-paced, fun and full of exciting new projects.  

Must be available to work on-site at our Bangalore office 5 days per week.

About the role:

As a Senior Staff Mechanical Engineer — Thermals, you will own the end-to-end thermal architecture, cooling strategy, and safety design for utility-scale Battery Energy Storage Systems (BESS), spanning outdoor cabinets and containerized platforms. You will define and architect Chiller-based, liquid-cooled, air-cooled, and hybrid thermal systems that support multi-MWh energy storage installations operating in demanding outdoor environments.

This role requires deep, hands-on expertise in thermal system design, advanced simulation, and BESS safety compliance. You will work closely with inverter, mechanical, electrical, controls, systems, safety, and manufacturing teams to ensure thermal solutions meet performance, reliability, manufacturability, serviceability, compliance, and cost targets — delivering production-ready designs from concept through deployment while optimizing CAPEX and long-term OPEX.

What will you do: 

• Own end-to-end thermal architecture, cooling strategy, and safety design for cabinet-level and containerized BESS platforms, from concept through production and field deployment.
• Define and architect Chiller-based, liquid-cooled, air-cooled, and hybrid thermal systems for power electronics — including heat exchangers, chillers, cooling plates, pumps, valves, manifolds, fans, ducting, and venting devices.
• Apply first-principles thermal engineering to design efficient, reliable, and cost-effective cooling solutions.
• Perform system-level and detailed thermal and CFD analysis, and translate results into production-ready, compliant designs.
• Lead arcing analysis, containment design with sensors, venting, pressure-relief mechanisms, and propagation-mitigation strategies.
• Drive DFMEA, root-cause analysis, and corrective actions based on test data and field feedback.
• Lead supplier selection and technical design reviews, balancing performance, reliability, manufacturability, and cost (CAPEX/OPEX).
• Support certification efforts and AHJ interactions across global safety and compliance standards.
• Provide technical leadership and mentor senior- and staff-level engineers.

  Who You Are and What You Will Bring:

• Bachelor's or Master's in Mechanical or Thermal Engineering with 12+ years of hands-on experience, including ownership of commercial and utility-scale BESS thermal architectures. Strong fundamentals in engineering mechanics and strength of materials.

• Expert-level proficiency in thermal and CFD simulations — system-level and detailed analysis, including airflow and system-flow simulations and transient and steady-state thermal analysis using tools such as Icepak, Fluent, COMSOL, and FLACS.
• Experience translating simulation results into production-ready, compliant designs, including analyses supporting NFPA 68 (deflagration venting) and NFPA 69 (explosion prevention).
• Deep experience leading thermal runaway analysis, containment design, venting, pressure-relief mechanisms, and propagation-mitigation strategies.
• Strong system-level understanding of PCS architectures, battery rooms, DC- vs. AC-coupled systems, and thermal coordination with BMS, EMS, and PCS derating logic.
• Demonstrated capability designing for high-ambient (45–55 °C), high-altitude, corrosive environments, and long-duration (2–8+ hour) energy storage systems.
• Expertise in reliability-driven thermal design, including 15–25-year system-life targets, redundancy, fail-safe and degraded-mode operation, and OPEX-optimized cooling strategies.
• Proven experience driving DFMEA, root-cause analysis, and corrective actions based on test data and field feedback.
• Experience leading supplier selection and technical design reviews, balancing performance, reliability, manufacturability, and cost (CAPEX/OPEX).
• Working knowledge of global safety and compliance standards, including UL 9540/9540A, NFPA 855/68/69, and IEC standards, with experience supporting certification and AHJ interactions.
• Strong technical leadership skills, with the ability to lead programs, influence architecture decisions, and mentor senior- and staff-level engineers.