Chief Battery Energy Storage System (BESS) Engineer

Fluence - Arlington, VA

Full-time - Senior

Arlington, VA

Utilities

About the position

The Chief BESS Engineer at Fluence is responsible for the technical authority over the design, development, and optimization of Battery Energy Storage Systems (BESS). This role involves directing the engineering strategy, ensuring integration across various engineering disciplines, and driving innovation to meet market demands. The Chief BESS Engineer will oversee the Chief Mechanical Engineer, Chief Thermal Engineer, and Chief Battery Engineer, ensuring cohesive performance and reliability of all subsystems.

Responsibilities

• Lead the overall design and technical strategy for BESS, maintaining full responsibility for system-level architecture and integration.
• Serve as the ultimate technical authority in Design Reviews, making decisions on design direction, performance criteria, and safety standards.
• Coordinate and align across the Enclosure, Systems, and Battery engineering teams, overseeing Fluence's Chief Engineering office.
• Direct integration of all BESS subsystems, ensuring mechanical, electrical, thermal management, power conversion, and battery technologies work together to optimize system performance.
• Set and enforce Fluence's engineering standards across all engineering disciplines, ensuring scalable and efficient system architecture that meets regulatory requirements.
• Define and approve key engineering decisions, ensuring design choices support long-term performance, reliability, and cost-effectiveness.
• Develop a long-term vision for BESS evolution, ensuring the company remains at the forefront of energy storage technology.
• Engage in strategic planning and product and technology roadmap development, aligning technical objectives with market trends and business goals.
• Facilitate strong collaboration between mechanical, electrical, power conversion, thermal, and battery engineering teams.
• Oversee the resolution of complex engineering challenges, providing guidance and support across technical disciplines.
• Ensure that full system testing protocols are in place to validate performance, safety, and reliability of BESS products.
• Lead risk assessments, identify critical system-level risks, and establish mitigation strategies for potential technical failures.
• Ensure compliance with all relevant industry standards and regulatory frameworks, including UL, CE, NFPA, and grid connection requirements.
• Provide leadership and mentorship to engineers, fostering a culture of excellence, innovation, and accountability within the organization.
• Build and nurture a highly skilled engineering team, encouraging cross-disciplinary learning and innovation.

Requirements

• Bachelor's degree in electrical engineering, Mechanical Engineering, or related field (Master's or Ph.D. preferred).
• 15+ years of experience in battery systems, energy storage, or related fields, with proven expertise in system-level design and integration.
• Strong track record of leading complex, multi-disciplinary engineering projects, particularly in BESS or power systems.
• In-depth knowledge of lithium-ion and alternative battery chemistries, thermal management, and mechanical systems for energy storage applications.
• Experience with large-scale, grid-connected energy storage projects and full-system testing protocols.
• Demonstrated ability to provide technical leadership and direction across multiple engineering disciplines.
• Strong decision-making abilities with a focus on optimizing performance, reliability, and safety.

Nice-to-haves

• Experience with Agile methodologies for hardware engineering.
• Knowledge of energy markets, grid operations, and regulatory requirements for energy storage systems.
• Familiarity with advanced simulation tools and digital twin modeling for system optimization.