Lead Thermal Design Engineer

Exowatt is revolutionizing the energy landscape for the AI era with our groundbreaking P3 system that captures solar energy, stores it as heat, and generates electricity on demand. Founded in 2023 and backed by leading investors including Andreessen Horowitz, Sam Altman, and Felicis, we're committed to providing clean, modular, and scalable power that meets the rapidly growing demands of AI infrastructure. Our mission is to make sustainable renewable energy always available and almost free, enabling technological advancement while protecting our planet. We are seeking a Lead Thermal Design Engineer to lead the design, development, and optimization of solar thermal receivers for our energy systems. In this role, you will own the engineering of components that absorb and transfer high-flux solar radiation into our thermal storage systems. You will work at the intersection of heat transfer, materials science, and optical engineering to push the boundaries of receiver efficiency, durability, and cost-effectiveness. This position is based in Miami, FL preferred, however an alternate location of Austin, TX is possible for the right candidate. If hired for this role, relocation to one of these sites is required. We provide relocation assistance.

Key Responsibilities

• Lead the end-to-end design and development of high-temperature solar receivers optimized for solar field integration
• Develop thermal and optical models to predict receiver performance, including flux distribution, heat transfer efficiency, and thermal stress analysis
• Select and qualify materials capable of withstanding extreme temperatures (800°C - 1000°C+), thermal cycling, and high solar flux environments
• Design receiver geometries (cavity, external, tubular, particle-based) to maximize energy absorption while minimizing thermal losses and mechanical fatigue
• Collaborate with solar collection and controls teams to optimize aiming strategies and flux distribution on receiver surfaces
• Interface with heat exchanger and thermal storage engineers to ensure seamless integration of receiver output with downstream systems
• Develop and execute testing protocols for receiver prototypes, including high-flux testing and accelerated life cycle evaluation
• Drive design-for-manufacturing initiatives to reduce receiver cost and improve producibility at scale
• Stay current with advances in receiver technology, high-temperature coatings, and selective absorber materials

Required Qualifications

• Bachelor's degree in Mechanical Engineering, Aerospace Engineering, Materials Science, or related field; Master's or PhD preferred
• 7+ years of experience in thermal systems design, with significant focus on high-temperature receiver or heat exchanger development
• Demonstrated expertise in solar thermal receiver design for tower-based or central receiver systems
• Strong background in heat transfer (conduction, convection, radiation), thermodynamics, and fluid mechanics
• Proficiency with thermal simulation tools (ANSYS, COMSOL, SolarPILOT, or equivalent)
• Experience with high-temperature materials including ceramics, refractory metals, and advanced alloys
• Hands-on experience taking receiver designs from concept through prototype testing and into production

Preferred Qualifications

• Experience with molten salt, liquid sodium, or particle-based heat transfer media
• Knowledge of selective absorber coatings and high-temperature surface treatments
• Familiarity with optical modeling and ray-tracing software for flux analysis
• Background in solar field optimization and aiming point strategies
• Publications or patents in solar thermal receiver technology

What We Offer: Competitive salary and equity options. Comprehensive benefits package, including health, dental, and retirement plans. A dynamic work environment that fosters creativity and innovation. Opportunities for professional growth and development in a rapidly evolving industry. Relocation assistance.