Sr/Staff Electrical Engineer at Mariana Minerals (San Francisco, CA)Sr/Staff Electrical Engineer

Mariana Minerals is a software-first, vertically integrated minerals company on a mission to supply the critical minerals powering modern energy, AI, and defense technologies. We’re reimagining the minerals supply chain by combining deep industry expertise with advanced software, automation, and data-driven decision-making.

We are hiring a Senior / Staff Electrical Engineer to own the medium and low-voltage power systems behind our refining and minerals processing facilities. From the incoming service point through the MV substations, e-houses, MCCs, and drives, down to the last motor and panelboard. You will set the electrical design basis for each facility and then work both sides of the line — self-performing the studies and packages that decide how the plant gets built, while reviewing and approving detailed engineering deliverables from third party engineering firms. You will carry that through procurement, into the field, and out through commissioning and energization.

• Own the MV/LV design basis. Voltage levels, system grounding, fault levels, load segregation, redundancy, and standby power
• Build and maintain the plant load list from process and mechanical equipment lists, and carry it through concept and detailed design
• Size and configure the distribution. Main MV switchgear, unit substations, e-houses and PDCs, MCCs, LV switchboards, and branch distribution down to the loads
• Build and maintain the ETAP model of each plant as the single source of truth, and keep it current as loads move
• Write datasheets and technical specifications for MV switchgear, unit substations, transformers, MCCs, LV and MV VFDs, UPS and DC systems, and modular e-houses
• Lead procurement including technical bid evaluation, vendor drawing review, FAT witness, and early management of the long-lead equipment
• Write the electrical scope of work in our third party engineering contracts, and review and approve deliverables
• Self-perform the packages that are faster or better done in-house
• Classify hazardous areas for hydromet, pyromet, and reagent handling areas, and design equipment accordingly
• Coordinate across multi-disciplinary detailed engineering phases
• Support construction and commissioning. RFI resolution and field changes, insulation resistance and hipot, relay injection, NETA ATS acceptance testing, and MCC and drive functional checks
• Write energization plans and switching procedures, phase energization through a plant still under construction, and close out with as-builts, setting files, and turnover packages

• 8+ years designing MV and LV power distribution for industrial process facilities, delivered in an EPC, owner’s-engineer, or capital projects environment
• Hands-on modeling in ETAP (preferred), SKM PowerTools, or EasyPower
• Depth in the core studies: load flow, short circuit, motor starting, protective coordination, and arc flash
• Specification and procurement track record on MV switchgear, unit substations, transformers, MCCs, VFDs, and e-houses
• Fluency in NEC, IEEE, NFPA 70E, and in hazardous area classification
• Comfortable both redlining EPC deliverables and producing them yourself when that is faster
• Bachelor of Science Electrical Engineering. PE strongly preferred

Our culture is built on four principles:

Everyone Gets Home Safe. We never put speed or cost ahead of people. Extreme Ownership. We take full responsibility for outcomes, relentlessly driving toward solutions. Engineer Out Requirements, then Automate. We simplify, optimize, and then automate for scale. Share Your Legos. We collaborate openly, share knowledge, and empower each other to build bigger, better solutions.

Join us as we build the future of responsible mineral sourcing and supply!