Senior Project Engineer - BESS

ON.energy; Reston (VA); Hybrid; USD 120,000 - 170,000; Full time

Benefits offered by this job

Competitive salary

Medical, dental, and vision insurance

401(k) with company match

Paid time off and holidays

Job summary

ON.energy is seeking an experienced Electrical/Mechanical Engineer to lead the engineering for Battery Energy Storage Systems across data centers and critical facilities. You will coordinate with internal teams, customers, and contractors to ensure design integrity and on-time delivery.

The role requires 5+ years in project engineering within BESS or electrical infrastructure, familiarity with ETAP/SKM, and travel up to 50%. Hybrid in the US, with options for remote work where feasible.

Qualifications

• Bachelor’s degree in Electrical, Mechanical, or related engineering field required.
• At least 5+ years in project engineering within BESS or electrical infrastructure sectors.
• Knowledge of high-voltage systems and energy storage equipment is essential.
• Ability to interpret electrical schematics, single-line diagrams, and layouts.

Responsibilities

• Support end-to-end engineering execution of BESS projects from development to commissioning.
• Act as the technical point of contact to the project manager and manage scope.
• Coordinate with internal teams to meet project milestones and budgets.
• Collaborate with customers, EPCs, OEMs, and consultants on integration.
• Review designs and vendor submittals for technical compliance and quality.
• Develop electrical diagrams, schematics, and wiring layouts for BESS systems.
• Prepare specs, data sheets, POs, and bid evaluations for electrical equipment.
• Run short circuit, load flow, and arc flash studies with ETAP/SKM.
• 75
• Assist in project schedules, procurement plans, and technical docs.
• Conduct site walks, FAT/SAT, and support field activities.

Skills

Electrical engineering

Mechanical engineering

Project engineering

Schematic drawing

ETAP

SKM

AutoCAD

Subcontractor management

Travel readiness

Cross-functional coordination

Education

Bachelor’s degree in Electrical or Mechanical Engineering

Tools

ETAP

SKM

AutoCAD

Job description

ON.energyis building the backbone of energy and AI infrastructure powering grid-safe data centers and mission-critical facilities. The company supplies and operates hyperscale power systems that solve the toughest resilience challenges, delivering custom solutions for AI data centers, mission-critical facilities, and front-of-the-meter assets. ON recently announced a 5GW partnership, with 3GW currently under construction across multiple hyperscale data center campuses. With patented technology and proprietary software,ON.energydevelops projects worldwide that set new benchmarks for resilience.

Location: Remote considered / Hybrid in Houston, TX or Tysons, VA preferred

Travel: 20-30% travel to project sites in the US

Responsibilities

• Support the end-to-end engineering execution of BESS projects for data centers, from development to commissioning.Manage the technical scope of projects and serve as the technical point of contract to the project manager.
• Coordinate with internal engineering, procurement, and construction teams to ensure project milestones are met.
• Collaborate with customers, EPC contractors, OEMs, and design consultants on integration of BESS with data center electrical infrastructure.
• Review and validate system designs (electrical, civil, mechanical) and vendor submittals to ensure technical compliance and quality.
• Design and develop Single line diagrams, Schematics, Wiring diagrams for Battery storage systems
• Prepare Electrical Equipment Specifications, Data Sheets, Purchase Requisitions and Bid evaluations for inverters, Switchgear, Transformers and other electrical equipment as required
• Develop Short circuit, load flow, and arc flash studies using software such as ETAP.
• Assist in developing project schedules, procurement plans, and technical documentation.
• Conduct site walks and support field activities during installation and commissioning.
• Participate in Factory and Site Acceptance Testing (FAT/SAT) of BESS components and systems.
• Identify technical risks and propose mitigation strategies in coordination with Project Management.
• Ensure all work is compliant with relevant codes (e.g., NEC, IEEE, NFPA) and On Energy Storage’s internal standards.

Required Qualifications

• Bachelor’s degree in Electrical Engineering, Mechanical Engineering, or other engineering discipline.
• 5+ years of experience in project engineering, preferably within the BESS, electrical infrastructure, or data center sectors.
• Familiarity with energy storage systems (CATL, Sungrow, Tesla, etc.) and high-voltage infrastructure.
• Strong understanding of electrical schematics, single-line diagrams, and equipment layouts.
• Strong understanding of the electrical system design, system studies, relay coordination, and protection & control.
• Proficiency in Microsoft Office, AutoCAD, power system study programs (Ex. ETAP, SKM).
• Basic understanding of Civil, Mechanical, and Structural work.
• Ability to read and understand project owner specifications and engineering drawings
• Ability to manage subcontractors and drive schedule of Engineering activities
• Ability to manage multiple projects concurrently
• Ability to problem solve issues and have an “outside the box” mentality
• Strong attention to detail, with the ability to recognize discrepancies
• Able to produce clear and concise documentation
• Strong work ethic
• Excellent interpersonal skills with the ability to work with clients and staff in a team.
• Excellent communication, problem-solving, and cross-functional coordination skills.
• Ability to travel to project sites across the U.S. as needed (up to 50%).

Preferred Qualifications

• Experience working on EPC or design-build projects in the energy or critical infrastructure sector in North America.
• Familiarity with commissioning protocols and QA/QC procedures for electrical systems.
• PE or EIT certification is a plus.
• Hybrid in office up to 3 days a week

For US-based roles - What you’ll get:

• Competitive salary + annual performance-based bonus eligibility
• Medical, dental, and vision insurance
• 401(k) with company match
• Paid time off and company holidays

For Mexico-based roles - What you’ll get:

• Competitive salary + annual performance bonus eligibility
• Christmas Bonus (Aguinaldo): 30 days
• Major medical expenses and life insurance
• Paid time off and holidays (per local policy)

For all roles:

• Professional development and growth opportunities
• Opportunity to grow with a mission-driven team shaping the future of clean energy
• Equal Opportunity: ON.energy is committed to equal employment opportunity and to maintaining a work environment free of harassment, discrimination, or retaliation.
• Accommodations: If you need an accommodation during the application process, email [e-mail]
• Benefits vary by role and location and are subject to change.