Principal Engineer, Power Systems Controls

MISSION TAR’s mission is to power intelligence for the world. We are building the world’s first off-grid power plant for data centers powered by renewable technologies. We firmly believe AI should be built in the US for the benefit of all people. For that, power must be fast, clean and cheap. We are singularly focused on delivering GW-scale power faster than anyone has ever done, by rethinking every layer of the stack. To deliver on this vision, TAR manufactures, deploys and operates off-grid energy assets with a renewable backbone. We vertically integrate to solve every bottleneck, from racking systems to power electronics to dispatch algorithms to on-site construction. Leave your mark by powering the future of civilisation-scale energy infrastructure. We hire people who care deeply about this problem space. If that is you, please apply! COMPANY We are a team of seasoned operators run by founders who previously scaled a company to over 80 people and $350M in annual sales. We know how to operate and we move fast. We are working directly with one of the largest compute providers to make our vision come true and plan to deploy 5GWs by 2028. TAR is both a hardware and software company, we are building out massive, critical, physical infrastructure. We operate on… - High ownership. High Agency. Own project end-to-end. Great people don’t need to be managed. - Speed. We achieve great things on incredible timelines. We always push ourselves to go faster. - First principles. No ego. No hierarchy. Challenge every assumption. - Passion. Solving the energy problem is one of the largest challenges that faces the world now and in the future. We put in long hours and hard work to solve this. ABOUT THE ROLE As Principal Engineer, Power Systems Controls, you own two things: how the power electronics behave in an inverter-dominant island, and the control architecture that ties every asset together. You translate architecture into single-lines, interrogate the grid-forming PCS and BESS down to the control level, define where OEM firmware ends and a separate system-level controller begins, and validate that the integrated plant holds frequency and voltage on its own, while powering a data center load 24/7, with no utility behind it. The hardest problems on this project live in controls and protection under islanded conditions, and this role owns the engineering answer to them. You drive the day-to-day electrical engineering under the Director of Power Systems Engineering. Two scope notes on what this role is and is not. First, we integrate utility-scale OEM equipment; we do not design power converters at the silicon level. We need someone who understands converter internals well enough to push OEMs hard on grid-forming behavior, ride-through, and protection, not someone who wants to lay out gate drivers. Second, you own the control architecture and its validation (the control philosophy, the OEM-firmware-versus-MGC boundary, the MGC and EMS functional specs, and proof that the integrated island is stable), but you do not personally write the PLC logic or stand up the SCADA. A controls and automation engineer plus the MGC and EMS vendors carry implementation under the architecture you set. RESPONSIBILITIES - Own the control hierarchy architecture for the islanded plant. Author the control philosophy, define where OEM grid-forming firmware ends and a third-party microgrid controller (MGC/PPC) begins, write the functional specifications for the MGC and EMS, and own multi-vendor controls integration end-to-end so no function falls into a gap between vendors. - Own the power electronics integration. Specify, evaluate, and validate grid-forming inverters and BESS PCS. Model and verify GFM control behavior, fault response, ride-through, and inverter-to-inverter interactions in an IBR-dominant plant with limited fault current, including EMT/PSCAD validation against usable OEM models. - Run and review islanded power-system studies: load flow, short-circuit, protection coordination, grounding, load following, load smoothing, and transient/load-step stability for a continuous high-density IT load. Solve the islanded protection problem directly: islanded fault current collapses to roughly 1.1 to 1.5x rated and conventional overcurrent coordination becomes less reliable, so specify the differential, communication-assisted, or adaptive scheme that stays selective across every operating mode. - Drive OEM technical engagement on PCS, BESS, and controls. Track FEOC-compliant equipment options where ITC eligibility is at stake. - Support permitting, interconnection, and the OE/IE with the electrical analysis they require. - Write commissioning and validation test plans. Support bring-up, acceptance testing, and field troubleshooting at the pilot and beyond. QUALIFICATIONS - BSEE, power systems, or related STEM discipline. - 7-10+ years in utility-scale solar, BESS, or power electronics, with hands-on ownership of SLDs and power-conversion integration. - Proficiency in electrical CAD and study tools (SKM, ETAP, AutoCAD Electrical, or similar) for one-line and study work. - Working knowledge of grid-forming versus grid-following inverter architecture and BESS PCS behavior. Able to read control specs critically, not just datasheets. - Strong NEC, UL 1741-SB, knowledge for PV, AC/DC coupling, and energy storage integration. - Experience with islanding controls, microgrid EMS/MGC, and inverter/PCS integration. - Able to model islanded systems, transient load response, and short-circuit/coordination studies, and to explain why islanded fault behavior breaks conventional overcurrent protection. - Extreme attention to detail with a bias for speed and rapid iteration. NICE TO HAVE - MSEE with a power electronics or microgrid focus. - Direct islanded, off-grid, or BTM microgrid experience. - Field-validated GFM behavior, fault response, ride-through, and inverter-to-inverter interactions in a real IBR-dominant or islanded plant with limited fault current. - Experience with EMT modeling of utility-scale PV+BESS powering a large variable load. - Hardware-in-the-loop (HIL) validation of inverter and BESS controls. - Written and executed commissioning/validation test plans and troubleshot bring-up in the field. - Test-like-you-fly culture (Tesla Energy, Fluence, SpaceX, Array, Nextracker, or comparable) where validation rigor is the norm. SALARY AND BENEFITS - Up to $15K relocation bonus - Unlimited PTO - Health, Dental, Vision insurance - $1K monthly stipend for meals