Senior Sales Engineer

Mainspring Energy manufactures and delivers fuel-flexible, low-emissions local power solutions that rapidly add new capacity and deliver reliable, affordable, and sustainable electric power. The company began commercial shipments of its Mainspring Linear Generators in 2020 and today has hundreds of megawatts in advanced development and field operations for leading Fortune 500 companies, data centers, and utilities. Mainspring also partners with global energy leaders including AEP, Next Era Energy Resources, Schneider Electric, and more.

core values

• Pragmatic Optimism
• Excellence without Ego
• Proactive Collaboration

The Senior Sales Engineer - Grid Scale reports to the Senior Sales Engineering Manager and serves as a senior technical contributor within the sales cycle for solution architecture, estimating, and system integration strategy on Mainspring's largest deployments: sites of 10 MW and above that either connect directly to the grid or serve large load sites such as data centers.

As a member of the Sales Engineering team (a subset of Project Delivery), this role exercises independent technical judgment to develop cost-optimized, execution-ready multi-MW plant solutions aligned with Mainspring's linear generator capabilities. The Senior Sales Engineer is accountable for architectural integrity, commercial rigor, and seamless transition from concept through execution, including a clean handoff of the design basis, estimate, and scope assumptions to Project Management and Project Engineering at contract award.

• Develop plant-level system architecture, preliminary designs (site layouts, single-line diagrams, medium-voltage collector and step-up transformer configuration, and point of interconnection scope), and cost estimates from concept through execution handoff.

• Articulate and support sound technical approaches, ensuring appropriate design integration and tradeoff evaluation (e.g., MV voltage selection, unit block sizing, redundancy and availability, grid-forming vs. grid-following operation).

• For large-load and data center sites, define at the proposal stage how the plant serves and protects the load, including islanding, load-following, black start, and transfer schemes.

• Define plant controls, communications, and protection scope (PPC, SCADA/EMS, utility telemetry, protective relaying, revenue metering) and the grid code (IEEE 1547/2800), ISO/RTO, and NERC requirements that drive equipment selection and cost.

• Produce complete, accurate, and timely proposal packages, including responses to utility, IPP, and data center developer RFPs, across multiple concurrent projects.

• Build well-supported cost estimates covering MV balance of plant, civil/structural, gas fuel systems, and interconnection facilities, proactively communicate risks, and incorporate market inputs into pricing assumptions.

• Develop EPC scopes of work and responsibility matrices that clearly split scope between Mainspring, the customer, EPC partners, and the utility, and that carry cleanly into contracts and project execution.

• Identify technical and commercial risk in customer specifications and contract terms (performance guarantees, availability, grid code compliance, interconnection cost exposure) and drive resolution before award.

• Support customer meetings, site walks, and solution presentations as the technical subject matter expert with utilities, IPPs, data center developers, and EPC partners.

• Communicate technical concepts in clear, structured, and solution-oriented formats across customer and internal stakeholders.

• Support the interconnection team on…