BESS solutions for engineering, procurement, and construction (EPC) firms

The integration certainty and documentation support you need to deliver complex BESS projects on schedule, all with a single point of accountability: FlexGen.

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Pre-Validated Integration

What arrives on-site is already proven

Integration issues discovered in the field are the single biggest source of schedule risk on BESS projects. By the time they surface, the damage to timelines and budgets is done. FlexGen’s Innovation Lab validates every hardware configuration, control narrative, and integration against HybridOS™ in a simulated grid environment before anything ships. What arrives on-site is already tested, documented, and ready to commission.

Computer-based virtual testing of Modbus communications
In-lab modeling and testing of unified AC+DC blocks
Site-specific HybridOS™ control narratives validated before field deployment
Automated test suites ready for deployment to additional blocks

Integrate any hardware. Protect your timeline.

Maintain BESS power through grid events

Because HybridOS™ is validated across 80+ battery and PCS configurations, FlexGen can support reliable integrations with whatever your project requires, without restarting the software process. EPCs don't always control hardware selection. When the OEM changes late in the procurement process, or the client switches configurations mid-project, the integration timeline is often the first to suffer. One software baseline. Any hardware. No surprises at commissioning.

80+ validated battery and PCS configurations
Pre-validated Modbus communications across OEM firmware versions
Software integration unaffected by late hardware changes
Full ITC compliance and supply chain traceability

Multi-Asset Orchestration

Eliminate asset conflicts and maximize availability

Complex BESS projects increasingly involve co-located solar, gas, or hybrid generation assets. Without coordinated control, conflicts between assets lead to equipment stress, unplanned outages, and performance shortfalls that become your problem at handoff. HybridOS™ protects onsite resources from physical wear and financial harm, while continuously coordinating the full asset stack. Sophisticated microgrid controls are validated in the lab before they reach your site.

Site-level microgrid orchestration
Islanding and seamless grid-to-island transition
Black start and grid resynchronization
Multi-asset conflict elimination

Documentation & Project Handoff

Every deliverable your end client expects. Ready at COD.

A successful BESS project doesn’t end at mechanical completion. It ends when the end client has everything they need to operate and finance the asset. Missing documentation or unresolved integration issues at handoff create liability long after the project closes. FlexGen’s standardized commissioning process produces a complete, audit-ready documentation package at every phase, from integration test records through market qualification certificates. One point of accountability means one complete handoff and rapid troubleshooting.

Full integration test documentation from the Innovation Lab
Standardized commissioning records at every phase
ISO and utility qualification certificates
HybridOS™ control narrative documentation

HybridOS™: the integration layer EPCs rely on

The most expensive BESS problems often surface during commissioning. HybridOS™, FlexGen’s energy management software, is pre-validated across 80+ battery and PCS configurations, giving EPCs a proven software baseline that integrates reliably, commissions predictably, and hands off cleanly to the end operator.

Learn more about HybridOS™ EMS

Peak Demand Management

HybridOS™ automatically manages state-of-charge to discharge during peak demand periods, reducing grid exposure and capturing revenue for the end operator.

Power Balancing

Dynamic coordination across batteries, generators, and variable generation assets. HybridOS™ continuously evaluates asset availability and operating limits to determine optimal real-time dispatch under all conditions.

Islanding & Seamless Transition

HybridOS™ enables automatic, graceful isolation from the grid during disturbances, maintaining continuity of operations without service interruption.

Grid Resynchronization

Real-time monitoring of voltage, frequency, and phase angle, with precise resynchronization execution to prevent transient disturbances.

Black Start

Coordinate gas turbine startup, manage transformer inrush current, and automatically sequence auxiliary system energization.

Low Voltage Ride-Through

Ride through short-duration voltage events without tripping offline. A compliance requirement increasingly specified by ISOs and utilities across major markets.

16+ years of experience  across energy markets

200+

Projects Completed

That’s enough storage capacity to provide electricity to more than 225,000 average U.S. homes.

25+ GWh

Under contract

That’s enough storage capacity to provide electricity to more than 225,000 average U.S. homes.

10+

Countries with active and contracted deployments

FlexGen supports a variety of energy projects across all 10 U.S. markets and internationally.

1.6m

Hours of battery runtime

Proven across capacity, flexibility, revenue generation, and backup power applications.

Frequently Asked Questions

What is FlexGen’s role in an EPC engagement?

FlexGen partners with EPCs across system design, integration, supply, commissioning, and project handoff. The company can extend that accountability through long-term lifecycle management services for the end operator.

What does One-Touch Commissioning™ mean for my schedule?

One-Touch Commissioning™ runs integration testing in our Innovation Lab in parallel with shipping and construction, meaning field commissioning starts from a validated baseline rather than a cold start. FlexGen gets energy storage systems online in as little as 14 days, which significantly streamlines the path to first revenue.

What does the integration validation process look like?

FlexGen’s Innovation Lab validates every hardware configuration, control narrative, and Modbus integration against HybridOS™ before field deployment. Virtual and in-lab testing confirm that the system is ready for commissioning before it ships. What arrives on site is already tested and documented.

How does FlexGen handle multi-asset sites?

HybridOS™ is designed for complex, multi-asset sites. Sophisticated microgrid controls are validated in the lab before field deployment — so EPCs aren’t resolving orchestration issues during commissioning. FlexGen supports islanding, black start, grid resynchronization, and full multi-asset conflict elimination across any site configuration.

What does the documentation package look like at handoff?

FlexGen’s standardized commissioning process produces a complete, audit-ready documentation package at every phase. That can include integration test records, commissioning reports, and HybridOS™ control narrative documentation. One point of accountability means one complete, compliant handoff to the end client.

Is FlexGen software-forward?

Yes. HybridOS™ is the constant across every project. Because our software is validated across 80+ battery and PCS configurations, EPCs aren’t locked into a single OEM, and can adapt as regulated market and supply chain conditions shift without restarting the software integration process.

What cybersecurity certifications does FlexGen hold?

FlexGen holds ISO 27001:2022 and ISO 27001:2013 certifications and has completed a NIS 2 Directive assessment. HybridOS™ is US-built, with security-first architecture designed for critical infrastructure environments. For the full certificate stack, visit trust.flexgen.com.

What markets does FlexGen operate in?

FlexGen has completed projects across all 10 U.S. energy markets and internationally, with deep integration experience in ERCOT, PJM, CAISO, MISO, and SPP.

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Ready to deliver your next BESS project on schedule?

FlexGen’s experts will walk through your project scope and integration requirements to show you exactly how One-Touch Commissioning™ will protect your timeline.

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