Commissioning is the process of turning an installed battery energy storage system (BESS) into a verified, operating asset. During this phase, teams test the equipment and software together to confirm that the site controls perform as they were designed.
Because commissioning depends on so many interconnected systems, stakeholders, and site-specific conditions, it’s one of the most complex stages of battery storage deployment. Exact timelines are difficult to predict, since delays can stem from a range of factors, from hardware issues to controls integration or coordinating across the various parties involved with the site.
For BESS projects, the commercial impact of a commissioning delay can be significant. Analysis by Modo Energy found that nearly 50% of all ERCOT battery revenues were earned over 20 days in 2024. If a system hadn’t reached commercial operation by those high-earning days, it would have missed a substantial share of its annual revenue opportunity.
Many commissioning variables are outside an integrator’s direct control, but there are still ways to manage that complexity and deliver more consistent, predictable outcomes.
A recent analysis by Orennia found that similarly sized FlexGen projects reached commercial operation on more consistent timelines than those of most other integrators. Behind that consistency is an integrated approach designed to minimize coordination challenges, reduce the risk of field issues, and maintain continuous forward momentum.
Over the past two years, FlexGen has also made project delivery more efficient, cutting project hours per MWh by more than 50%. During a recent project with SMT and Irby Construction, FlexGen commissioned a 160 MW battery storage site in Texas in only six weeks, which was three times faster than a more typical 25-week timeline.
Our fast, reliable One-Touch Commissioning® approach allows us to validate configurations, control logic, and grid interactions in a grid-connected lab environment, significantly reducing commissioning time in the field. To further simplify the process, FlexGen’s approach to deploying and operating energy storage systems is to act as the sole point of accountability across the entire project lifecycle.
Streamlined commissioning starts early with design and lab testing
Before a BESS project reaches the field commissioning phase, there are ways to ensure a smoother, more predictable path to commercial operation.
During project design, an energy management system (EMS) partner like FlexGen can help define how a complete power system needs to perform and develop the software controls required to carry out those use cases, for standalone BESS, hybrid sites, and large load campuses. FlexGen’s application engineers are instrumental in meeting project schedules, commercial targets, and technical requirements. They address site-specific control requirements, ensure proper project sizing, and identify the best hardware combinations in a dynamic supply chain environment. When these important considerations happen during the design phase, commissioning is more predictable and assets perform as they are expected.
From there, we fine-tune a project’s hardware configuration with HybridOS™ EMS software in our Innovation Lab. This process can occur while hardware is being shipped to the project site or while construction is underway, streamlining the overall commissioning stage.
Lab testing can expose incorrect Modbus mapping, firmware compatibility issues, or control responses that do not meet expectations. The goal is to resolve those issues quickly and then repeat tests in a controlled environment.
FlexGen has tested and validated over 80 hardware configurations in the Innovation Lab, significantly reducing the risk of projects encountering compatibility issues for the first time during field commissioning.
Additionally, HybridOS™ EMS software has been deployed across hundreds of BESS sites, configurations, and use cases. All of FlexGen's sites are run from a single HybridOS codebase which has experienced edge cases from over 13 million hours of runtime. Those lessons learned, plus an internal feedback loop across software, integration, commissioning, and operations, make for an EMS that can optimize asset performance while managing real-world conditions proactively. All of that historical knowledge also translates into process automation and proactive recommendations, reducing the need for teams to troubleshoot and manually solve the same types of problems where a solution has already been found.
Expanding the productive commissioning window with FlexGen’s Remote Operations Center
Additional time can be shaved off field commissioning with overnight remote support. Many tasks during this process require qualified personnel on site, including physical inspections, wiring corrections, and equipment replacement. However, some commissioning tests can be performed remotely. FlexGen’s 24-7 Remote Operations Center (ROC) can support some aspects of commissioning work overnight, so progress doesn’t have to stop when the daytime field crew leaves.
Whether the ROC can run a particular test or operating sequence overnight depends on the site’s commissioning status, approved procedures, remote-control authority, and required local coverage. When possible, though, this around-the-clock support can expedite commissioning timelines.
Lab integration, One-Touch Commissioning®, and 24-7 remote operations have proven to make for faster and safer BESS commissioning. And FlexGen derisks projects even further by delivering full-wrap energy storage systems from the design to sourcing to energization, followed by over a decade of operations.
Reducing complexity through a single point of accountability
The commissioning phase of a BESS project often requires a large group of stakeholders, including equipment manufacturers, integrators, software providers, EPCs, utilities, and project owners. The more complex a project is, the more valuable it becomes to consolidate accountability. If responsibilities are fragmented among providers, troubleshooting may require extensive coordination, leading to delays.
FlexGen’s approach to deploying and operating energy storage systems brings together technical engineering expertise, established OEM relationships, sophisticated controls software, 24/7 remote monitoring, and field services. When we serve as the single point of accountability, our customers spend their time on what matters most, not coordinating a web of partners and stakeholders.
In that role, FlexGen can identify, escalate, and resolve problems faster, even when the underlying issue originates from a third party. For example, if a hardware integration issue arises, our supply chain specialists have direct lines of communication, executive relationships, and volume-based priority with OEMs worldwide and can work with them to resolve it quickly. If equipment rules or requirements change mid-project, we can help project owners shift to an alternative hardware choice while keeping timelines on track.
While we can never control every variable affecting a project schedule, consolidated responsibility is a significant factor in delivering faster, more consistent commissioning. And, that single point of accountability doesn’t stop serving the customer at COD. With a FlexGen Energy Storage System, we provide a single system performance guarantee consisting of power, energy, and round-trip efficiency that covers everything from the site level, down to each component, backed by liquidated damages and FlexGen’s bonding.
Speed and consistency are built into the process
Commissioning will always involve complex systems, multiple stakeholders, and conditions unique to each site. But faster, more predictable commissioning is possible through preparation, coordination, and managing complexity throughout project delivery.
FlexGen’s integrated approach begins during design and carries through lab testing, field integration, and operational support. Clear accountability, pre-tested configurations, and coordinated issue resolution help keep our projects moving.
By treating commissioning as a discipline that begins well before equipment reaches the field, FlexGen helps owners plan with greater confidence and bring assets into operation sooner, accelerating the timeline to their first revenue dollar.
