Principal Electrical Engineer - Power Plant Integration Lead

Job Overview As we scale our deployments from Behind-The-Meter (BTM) commercial microgrids to utility-scale Front-of-the-Meter (FTM) power plants and data centers, we are expanding our system boundaries to provide fully integrated, turn-key power solutions. This role sits at the intersection of power systems engineering, cross-functional hardware integration, and external vendor management. You will own the technical architecture and vision of how Mainspring power plant sites are built, including full ownership of the modular power skids. This includes ownership of the broader site: how generators, inverters, skids, and energy storage come together as a complete and configurable power solution. You will act as the technical anchor, translating high-level single-line diagrams and architectural concepts into robust, mass-manufacturable modular skid-based products. The ideal candidate will bridge the gap between initial concept and factory-ready design by driving requirements across internal multidisciplinary teams (Electrical, Mechanical, Project Delivery, Software Controls, and Supply Chain) while managing critical 3rd-party design and manufacturing partners to scale the product line.

Responsibilities

• Take full engineering ownership of Mainspring's next-generation modular power integration skids, actively translating high-level system architectures into fully commercialized, production-ready assets by driving the design from initial concept through validation and final manufacturing release

• Define and own the skid-level power topology for utility-scale and data center sites, ensuring seamless electrical and physical integration between Linear Generators, central inverters, step-up transformers, switchgear, and energy storage systems (BESS)

• Own detailed skid engineering decisions: hardware selection, spatial layout, thermal management, environmental protection (NEMA/IP rating, seismic/wind loading as applicable), manufacturability, and field serviceability

• Partner actively with internal electrical engineering, mechanical engineering, project delivery, operations, software controls, and supply chain teams to extract, synthesize, and freeze comprehensive system requirements

• Direct and manage third-party design firms and external manufacturers, serving as the primary technical point of contact to ensure engineering and manufacturing outputs align with technical specifications and quality standards

• Drive the scalability and production readiness of larger skid configurations alongside manufacturing suppliers, ensuring the architectural design leverages standardized hardware, reduces site-level installation labor, and is optimized for high-volume replication

• Own the skid's cost target and drive design-to-cost trade-offs across hardware selection, supplier strategy, and configuration options

• Develop a site design configuration tool that specifies the optimal inverter and skid configuration based upon customer site requirements

Qualifications

• Bachelor's or advanced degree in Electrical Engineering or a related field

• 24+ years of direct experience productizing complex, multi-disciplinary industrial systems

• Deep technical knowledge of power conversion systems, including medium-voltage (MV) step-up transformers (12.47kV–35kV), central inverters, switchgear, vacuum circuit breakers, protective relays, and high-current busbar/cabling systems

• Demonstrated experience driving the engineering lifecycle of modular hardware systems, including a strong grasp of design-to-cost principles, supplier capacity scaling, field reliability, and configuration control

• Strong cross-functional leadership skills with a track record of translating diverse technical requirements from electrical, mechanical, and operations teams into a cohesive, manufacturing-ready system design

• Demonstrated success directing 3rd-party design, engineering, or Contract Manufacturing (CM) partners from initial concept through to sustained volume production

• Strong working knowledge of grid interconnection standards, utility protection schemes, and safety/compliance frameworks (e.g., IEEE 1547, UL 1741 SB/SA, NFPA 70/NEC, NFPA 855)

Bonus Qualification(s)

• Skilled in SCADA integration, industrial networking, and designing or certifying control systems to UL 508/508A standards

221000 - 260000 USD a year

This position is onsite at our Menlo Park HQ. The salary will be adjusted to reflect local market conditions based on employee location as well as the experience of the employee. Along with the base salary, Mainspring offers pre-IPO stock options + benefits.