Principal Engineer, Thermal
Description
Enphase Energy is a global energy technology company and a leading provider of solar, battery, and electric vehicle charging products. Founded in 2006, our innovative microinverter technology revolutionized solar power, making it a safer, more reliable, and scalable energy source. Today, the Enphase Energy System enables users to make, use, save, and sell their own power. Enphase is also one of the most successful and innovative clean energy companies in the world, with more than 80 million products shipped across 160 countries.
Join our dynamic teams designing and developing next-gen energy technologies and help drive a sustainable future!
About the role
As a Principal Thermal Engineer, you will lead the thermal architecture, design, analysis, and validation of Enphase’s next‑generation battery and energy storage products. This role requires deep expertise in heat transfer, fluid dynamics, thermal system design, and the integration of cooling strategies into electro‑mechanical assemblies containing high‑power electronics and lithium-ion cells.
You will collaborate closely with global mechanical, electrical, reliability, and manufacturing teams. Your ability to communicate complex thermal behavior, risks, design trade‑offs, and test findings clearly—both verbally and in writing—is essential.
In this role, you will drive new product development with a focus on thermal performance, safety, reliability, and scalability of high‑volume energy-storage systems.
What you will be doing
Thermal Architecture & Design
• Develop and own the thermal architecture for battery packs, power electronics, and high density energy‑storage systems.
• Define cooling strategies (passive/active), heat spreader designs, venting/airflow concepts, and cell-to-pack thermal management schemes.
• Perform detailed thermal design incorporating conduction, convection, radiation, and transient load analysis.
• Establish thermal design requirements and ensure compliance across multiple subsystems.
Simulation, Analysis & Modeling
• Build detailed FEA/CFD thermal models (steady state & transient) to predict temperature distribution, gradients, hotspots, and thermal runaway behavior.
• Evaluate cooling concepts using simulation, trade-off analysis, and sensitivity studies.
• Perform cell, module, and pack-level thermal simulations for charge/discharge cycles, peak loads, and abuse events.
Testing, Validation & Safety
• Develop and execute thermal validation plans for in-house and external labs.
• Analyze test data, correlate with thermal models, and drive design improvements.
• Support thermal runaway mitigation strategies, venting/containment design, and safety compliance testing.
Cross Functional Collaboration
• Work with mechanical/electrical teams to integrate thermal solutions.
• Collaborate with cell engineering on thermal constraints.
• Partner with reliability and compliance teams.
• Review supplier designs, material selections, and manufacturing processes.
Who you are and what you bring
• Bachelor’s degree (15+ yrs exp) or Master’s degree (13+ yrs exp) in Mechanical Engineering, Thermal Engineering, Heat Transfer, or related field.
• Deep experience designing and validating thermal systems for high‑power electronics, battery packs, or energy‑ storage products.
• Experience in high-volume consumer electronics, EV batteries, ESS, or high‑ power inverter products.
• Experience with ECAD/MCAD and multi-physics modeling.
• Proven model-to-test correlation experience.
• Experience with UL 9540/9540A, UL 1741, and IEC safety standards.
• Experience with thermal runaway and lithium-ion safety.
• Familiarity with TIMs, heat sinks, PCM, insulation, and venting.
• Strong experience with environmental & reliability testing.
• Excellent communication skills.