Staff Embedded Firmware Engineer - Thermal Controls, BESS

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

Do you want to help change the world? This position sits within a team that develops fully functional prototypes from scratch to demonstrate new, advanced operation and control for autonomous grid connection, management, and regulation.

As a Staff Embedded Firmware Engineer focused on thermal controls, you will design and develop the real-time control firmware for our Battery Energy Storage System (BESS) cooling systems — implementing closed-loop control of pumps, valves, fans, chillers, and heat exchangers, along with temperature regulation, thermal protection, and safety logic — and working closely with thermal, mechanical, and hardware engineers to bring prototype designs to life from concept through validation. You will also mentor junior engineers and contribute to the team's technical direction.

What You Will Do

• Define and develop new control concepts for the thermal/cooling system and its sub-systems.
• Design and implement real-time thermal control firmware, including closed-loop control of pumps, valves, fans, chillers, and heat exchangers, and temperature and flow regulation.
• Design firmware for functional safety and thermal protection, supporting compliance with UL 9540A, NFPA 855, UL1741, IEEE 1547, and IEC 62109 standards.
• Integrate and process sensor data (temperature, pressure, flow, coolant level) for closed-loop control and fault detection.
• Develop and simulate control algorithms for cooling optimization, thermal regulation, and energy-efficient operation.
• Develop unit and system test software.
• Validate control algorithms using system simulation and thermal models.
• Work with thermal, mechanical, and hardware engineers to test and troubleshoot prototype designs.
• Perform firmware testing prior to design releases to the QA team.
• Organize thorough PR reviews, documentation rigor, and well-managed release branches.
• Accelerate firmware development and testing flow utilizing AI tools.
• Mentor junior engineers and contribute to the team's technical direction.

Who You Are and What You Bring

• BS/MS in Electrical Engineering, Controls/Mechatronics, and/or Power Electronics/Power Systems.
• 8 years of experience in embedded software or firmware design and development, preferably in electrical/control systems and/or power electronics products.
• Strong experience developing firmware for thermal or cooling control systems, including closed-loop control of pumps, valves, fans, and chillers.
• Expertise in C, C , and Assembly for real-time applications.
• In-depth experience coding in FreeRTOS and bare-metal environments.
• Ability to understand and implement digital signal processing (DSP) and closed-loop control (e.g., PID) concepts in a 32-bit or larger microprocessor environment.
• Experience interfacing with and processing data from temperature, pressure, and flow sensors.
• Familiarity with evaluating CPU versus hardware processing requirements and trade-offs for cost-effective designs.
• Ability to troubleshoot firmware-related issues within complex systems, including hands-on testing in the lab.
• Ability to test code and hardware both with and without external test equipment such as oscilloscopes, power meters, and similar instruments.
• Ability to carry a design task from concept to implementation.
• Ability to document engineering requirements, document solutions, and test new firmware designs.

What Will Make You Stand Out

• Familiarity with software development processes (e.g., Agile, structured, object-oriented).
• Familiarity with development tools such as GCC, GDB, Eclipse, and GNU Make.
• Familiarity with source code management tools such as Git and Mercurial.
• Experience with Zephyr RTOS.
• Familiarity with firmware build pipeline tools such as Bitbucket, Docker, GitHub, and JFrog; experience with CI/CD release processes is a plus.

Work Location

This role requires being on-site at our Austin, Texas office 5 days per week.

The base pay range for this position is $100,000 to $151,000 per year. This salary range may be modified in the future. The successful candidate’s starting pay will be determined based on job-related skills, experience, education or training, work location, and market conditions. This position is also eligible for bonus, equity, and benefits.

Salary : $100,000 - $151,000