On.Energy Project Manager Interview Questions & Guide 2026

A Project Manager at On.Energy plays a pivotal role in accelerating the global transition to clean energy. In this position, you are responsible for leading the execution of utility-scale and commercial & industrial (C&I) Battery Energy Storage Systems (BESS). On.Energy is a specialized energy storage integrator, which means the company does not just build projects; they design, integrate, and deploy highly complex systems that combine tier-1 battery hardware, power conversion systems, fire suppression technology, and their own proprietary Energy Management System (EMS) software.

Your impact in this role is direct and measurable. You will own the lifecycle of energy storage projects from the initial engineering handoff, through procurement, civil and electrical construction, utility interconnection, and final commissioning. These systems are critical for grid stability, peak shaving, and integrating renewable energy sources. As a Project Manager, you ensure these multi-million dollar assets are delivered safely, on time, and within budget, directly influencing On.Energy’s market reputation and financial success.

What makes this role uniquely challenging and rewarding is its highly cross-functional nature. You are the central node connecting engineering, supply chain, regulatory bodies, local utilities, and EPC (Engineering, Procurement, and Construction) contractors. You must navigate the technical complexities of high-voltage electrical engineering while simultaneously managing commercial risks, supply chain bottlenecks, and complex local permitting requirements.

The interview process at On.Energy is designed to evaluate both your technical execution capabilities and your commercial acumen. While questions are tailored to the specific scale of projects you will manage, they consistently focus on your ability to deliver complex infrastructure projects under tight constraints.

The following categories outline the typical questions you should prepare for, reflecting real-world scenarios faced by Project Managers in the energy storage sector.

Technical & Energy Storage Domain

This category tests your understanding of BESS components, electrical engineering fundamentals, and the specific challenges of integrating battery systems with the utility grid.

Explain the step-by-step commissioning process for a utility-scale Battery Energy Storage System (BESS).

How do you ensure compliance with safety standards such as NFPA 855 during the design and construction phases?
Describe your experience working with medium-to-high voltage systems and step-up transformers.
What are the key differences in project execution when managing a behind-the-meter (BTM) C&I project versus a front-of-the-meter (FTM) utility-scale project?
How do you coordinate the integration of a proprietary Energy Management System (EMS) with third-party hardware?

Project Control & Execution

These questions evaluate your ability to manage schedules, budgets, and contract mechanisms to keep projects on track.

Walk me through how you build and maintain a project schedule using the Critical Path Method (CPM). What tools do you prefer?
Describe a time when a critical-path item (such as an inverter or transformer) was delayed. How did you mitigate the impact on the overall schedule?
How do you manage budget variances, and what is your process for approving change orders from EPC contractors?
Explain how you handle milestone billing and cash flow forecasting on a project with long-lead equipment procurement.
What metrics do you use to measure the health and progress of a project on a weekly basis?

Behavioral & Stakeholder Management

These questions assess your communication skills, leadership style, and ability to resolve conflicts with clients, contractors, and internal teams.

Describe a situation where you had to manage a difficult EPC contractor who was failing to meet safety or quality standards. How did you handle it?
How do you manage expectations with an off-taker or client when a project faces unavoidable utility interconnection delays?
Tell me about a time you had to resolve a technical conflict between your internal engineering team and an external contractor on-site.
How do you prioritize competing demands when managing multiple BESS projects in different geographic regions simultaneously?
Give an example of a project risk you identified early in the execution phase and the steps you took to mitigate it before it became an issue.

Preparing for an interview at On.Energy requires a dual focus on technical execution and collaborative leadership. You must demonstrate that you can speak the language of electrical engineers and civil contractors while maintaining a sharp focus on commercial outcomes and safety.

Tip

Be prepared to discuss specific technical standards during your interviews. Familiarity with NFPA 855 (Standard for the Installation of Stationary Energy Storage Systems) and local utility interconnection processes will immediately set you apart as a knowledgeable candidate.

To stand out, align your preparation with these key evaluation criteria:

Technical & BESS Acumen – You must understand how a battery storage system works, including the roles of the battery management system (BMS), power conversion system (PCS), and energy management system (EMS). Interviewers will evaluate your ability to read single-line diagrams, understand utility interconnection requirements, and discuss commissioning protocols.

Project Controls & Risk Mitigation – You need to show deep expertise in scheduling, budgeting, and risk management. Be ready to explain how you identify critical path activities, manage contingency funds, and implement recovery plans when projects fall behind.

Contract & Vendor Management – A significant portion of your job will involve managing EPC contractors and equipment vendors. You must demonstrate a strong understanding of contract structures, liquidated damages, change order processes, and milestone verification.

Leadership & Adaptability – Energy storage is a fast-evolving industry with frequent regulatory and supply chain shifts. Interviewers look for self-starters who can navigate ambiguity, make data-driven decisions under pressure, and maintain strong relationships with diverse stakeholders.

The interview process at On.Energy is structured to thoroughly evaluate your technical capability, project management methodology, and cultural alignment. It is a rigorous but transparent process designed to ensure that you are fully equipped to handle the high-stakes environment of energy project execution.

You will begin with an initial screening call with a recruiter to discuss your background, salary expectations, and high-level fit for the role. Following this, you will transition into a series of technical and behavioral interviews. The process typically includes a deep-dive technical interview with the hiring manager, a practical case study or scenario-based discussion, and a final round of interviews with key cross-functional partners from engineering, procurement, and executive leadership.

Throughout this process, On.Energy prioritizes candidates who demonstrate a hands-on, problem-solving mindset. They look for practical execution experience rather than theoretical knowledge, focusing heavily on how you have handled real-world project challenges in the past.

The visual timeline above outlines the typical progression of the interview stages. You should use this to pace your preparation, focusing first on high-level behavioral storytelling and then diving deep into technical and scheduling scenarios as you progress. While the exact duration can vary based on the specific project pipeline and location, the process is designed to move efficiently.

Note

Do not treat the case study or scenario-based round lightly. This is where interviewers look for granular detail on how you manage schedules, budgets, and contractor disputes. Use real metrics and structured methodologies in your responses.

To succeed in the On.Energy interview process, you must excel across several distinct core competencies. Below is a detailed breakdown of these primary evaluation areas, including the specific topics you must master.

EPC and Contractor Management

Managing external Engineering, Procurement, and Construction (EPC) contractors is one of the most critical aspects of the Project Manager role. You are the owner's representative on-site, ensuring that contractors perform work safely, to specification, and within the agreed-upon contract terms.

Be ready to go over:

Subcontractor oversight – How to establish clear key performance indicators (KPIs) for civil and electrical subcontractors.
Change order validation – The process of auditing contractor claims for extra time or money, ensuring they are contractually justified.
On-site safety leadership – Implementing and enforcing zero-incident safety cultures, including OSHA compliance and site-specific safety plans.
Advanced concepts (less common) – Multi-prime contracting strategies (managing separate civil, electrical, and integration contractors directly rather than using a single turnkey EPC).

Example questions or scenarios:

"An EPC contractor claims that unforeseen subsurface rock formations will delay civil work by three weeks and cost an additional $100,000. How do you verify this claim and negotiate the change order?"
"How do you handle a situation where a subcontractor is consistently failing to meet the quality standards for cable terminations, but stopping their work will delay the overall project schedule?"

Interconnection and Commissioning

Bringing a BESS online requires navigating complex regulatory frameworks and technical testing protocols. You must coordinate closely with utilities and testing engineers to safely energize the system and achieve commercial operation.

Be ready to go over:

Utility coordination – Managing the Interconnection Agreement (IA) milestones, witness testing schedules, and utility telemetry requirements.
Point of Interconnection (POI) requirements – Understanding the physical and electrical requirements of connecting to the utility grid.
Commissioning sequences – Step-by-step testing of the battery cells, inverters, HVAC systems, fire suppression, and EMS control loops.
Advanced concepts (less common) – Coordinating black-start capability testing, microgrid islanding transitions, and capacity degradation testing protocols.

Example questions or scenarios:

"Describe your experience managing a utility witness test. What steps do you take to prepare your team and equipment to ensure a successful testing day?"
"The utility informs you that the telemetry link (SCADA) is not communicating with their control center, delaying your permission to operate (PTO). How do you troubleshoot and resolve this issue?"

Project Finance and Risk Mitigation

As a Project Manager, you are ultimately responsible for the financial performance of your projects. You must balance execution speed with cost control to protect On.Energy's profit margins.

Be ready to go over:

Milestone payment structures – Aligning project milestones with cash inflows from clients and outflows to equipment vendors.
Risk registers – Developing and actively maintaining qualitative and quantitative risk registers to identify and mitigate project threats.
Liquidated Damages (LDs) – Understanding how to draft and enforce contract clauses related to delay damages and performance guarantees.
Advanced concepts (less common) – Managing currency fluctuation risks for imported components and navigating tariff compliance (e.g., Section 301 tariffs on lithium-ion batteries).

Example questions or scenarios:

"How do you structure a project budget contingency, and what is your methodology for releasing contingency funds as project risks are retired?"
"Your client has a hard deadline for tax equity financing that requires the project to achieve COD by December 31st. What acceleration strategies do you deploy if you find yourself two weeks behind schedule in October?"

As a Project Manager at On.Energy, your daily activities will span tactical site management and strategic commercial oversight. You will act as the single point of contact for your assigned projects, driving them from contract signing to final handoff to the asset management team.

Your primary responsibilities will include:

Project Planning and Scheduling – Developing comprehensive project execution plans, detailed Gantt charts, and resource allocation plans using MS Project or Primavera P6.
Cross-Functional Leadership – Leading weekly project meetings with internal engineering, procurement, software, and business development teams to ensure alignment on deliverables.
Procurement and Supply Chain Coordination – Coordinating the timely delivery of long-lead equipment (batteries, PCS, transformers) to the project site, managing logistics and customs clearance as needed.
Contractor and Site Management – Overseeing on-site construction activities, managing EPC partners, conducting safety audits, and ensuring compliance with local building codes and environmental permits.
Financial Management – Tracking project costs against the approved budget, managing cash flow, reviewing and approving invoices, and reporting financial variances to leadership.
Commissioning and Closeout – Leading the system commissioning process, securing utility permission to operate (PTO), and compiling the final closeout documentation package (as-builts, warranties, O&M manuals).

On.Energy looks for candidates who possess a robust blend of technical engineering knowledge, rigorous project management discipline, and strong commercial instincts.

Must-Have Qualifications

Education – Bachelor’s degree in Electrical Engineering, Mechanical Engineering, Civil Engineering, Construction Management, or a highly related technical field.
Experience – A minimum of 3 to 7+ years of direct project management experience in utility-scale solar, wind, or energy storage projects.
Project Controls – Proven expertise in scheduling software (MS Project or Primavera P6), budget management, and executing projects within formal stage-gate frameworks.
Contract Experience – Direct experience managing EPC contracts, equipment supply agreements, and navigating utility interconnection processes.
Travel – Willingness to travel up to 30-40% to project sites, vendor facilities, and corporate offices as required by project lifecycles.

Nice-to-Have Qualifications

Certifications – Project Management Professional (PMP) certification is highly preferred.
BESS Expertise – Direct experience with lithium-ion Battery Energy Storage Systems (BESS), including familiarity with tier-1 battery integration and thermal management systems.
Language Skills – Bilingual proficiency in English and Spanish is a significant advantage, given On.Energy's active presence and project pipeline in Latin America.
Software Familiarity – Experience with SCADA systems, power system modeling tools, or proprietary Energy Management Systems (EMS).

Q: How technical does a Project Manager at On.Energy need to be? A: You do not need to be a design engineer, but you must be highly technically competent. You need to be comfortable reading electrical single-line diagrams, understanding battery degradation curves, and discussing inverter settings and SCADA communications with engineers and utility technicians.

Q: What is the typical travel requirement for this role? A: Travel typically ranges from 20% to 40%. It is highly cyclical; you will spend more time on-site during critical phases such as site mobilization, major equipment delivery, utility interconnection testing, and final commissioning.

Q: How are project teams structured at On.Energy? A: You will typically lead a dedicated matrixed project team. This includes a dedicated lead project engineer, a procurement specialist, a logistics coordinator, and commissioning technicians, all supported by the broader engineering and software development organizations.

Q: What makes On.Energy's project management unique compared to other renewable energy companies? A: Unlike pure-play solar or wind developers, On.Energy is an integrator. This means you are managing the deployment of both hardware and proprietary software (the EMS). This requires a deeper understanding of software integration, controls, and real-time battery performance optimization.

Q: What is the typical timeline of the hiring process? A: The entire process, from the initial recruiter screen to a formal offer, typically takes between 3 to 5 weeks, depending on candidate availability and the scheduling of cross-functional interview panels.

Tip

If you are interviewing for a remote position, be prepared to demonstrate how you manage remote teams, maintain contractor accountability from afar, and utilize digital collaboration tools to keep projects on schedule.

To maximize your chances of success during the On.Energy interview process, keep these practical tips in mind:

Emphasize Safety Above All – In utility-scale energy projects, safety is the absolute top priority. Weave safety into every answer you give. Mention daily safety tailgates, OSHA standards, and hazard mitigation when describing your past projects.
Use the STAR Method – Structure your behavioral answers clearly. Define the Situation, describe the specific Task you needed to accomplish, detail the Action you personally took, and highlight the quantifiable Result (e.g., "delivered project 2 weeks ahead of schedule," "saved $50,000 in contingency budget").
Understand the Supply Chain – The BESS industry is heavily impacted by global supply chain dynamics. Demonstrate that you are aware of current lead times for high-voltage transformers, battery cell availability, and logistics challenges.
Highlight Software Integration – Since On.Energy prides itself on its proprietary EMS, show that you understand the critical role software plays in battery performance, safety monitoring, and revenue generation.

Note

Avoid speaking in generalities. When asked about managing a project delay, do not just say "I communicated with the client." Explain exactly how you updated the CPM schedule, drafted the formal delay notice under the contract, and presented a recovery plan to the client with calculated cost-benefit trade-offs.

A Project Manager position at On.Energy is an exceptional opportunity to be at the absolute forefront of the energy transition. You will manage complex, high-impact projects that directly enable the integration of renewable energy and build a more resilient grid. By combining technical execution, commercial discipline, and collaborative leadership, you can drive multi-million dollar projects to success.

As you prepare for your interviews, focus heavily on structuring your past experiences into clear, metric-driven stories. Ensure you can speak confidently about BESS technology, EPC contractor management, project scheduling, and safety protocols. A structured, proactive approach to your preparation will demonstrate that you possess the exact organizational and leadership skills required to excel in this role.

To explore additional interview insights, detailed company reviews, and preparation resources tailored to the energy and technology sectors, you can access comprehensive tools on Dataford.

The salary data above outlines the compensation ranges for Project Manager and PMO coordinator positions at On.Energy across various locations and experience levels. When preparing for your interviews, use this data to benchmark your compensation expectations based on the specific location and seniority of the role you are targeting. Remember that total compensation at On.Energy often includes performance-based bonuses aligned with successful, on-time project delivery.

Interview Guides

On.Energy Project Manager interview questions & guide 2026

What is a Project Manager at On.Energy?

Common Interview Questions

Technical & Energy Storage Domain

Project Control & Execution

Behavioral & Stakeholder Management

The questions most likely to come up

See how a strong candidate would approach this

Prioritizing Across Competing Client Projects

Getting Ready for Your Interviews

Tip

Interview Process Overview

The interview process, end to end

Note

Deep Dive into Evaluation Areas

EPC and Contractor Management

Interconnection and Commissioning

Project Finance and Risk Mitigation

What they actually test for

Key Responsibilities

Role Requirements & Qualifications

Must-Have Qualifications

Nice-to-Have Qualifications

Frequently Asked Questions

Tip

Other General Tips

Note

Summary & Next Steps

What this role pays