RES identifies system integration and regulatory compliance as leading causes of U.S. battery storage project delays at commissioning
Battery storage projects in the U.S. are stalling — but not because of the batteries. According to findings published by global renewable energy company RES, the primary failure point at commissioning is system integration: specifically, getting the energy management system, SCADA, plant controller, BMS, and power conversion system to work together under real operating conditions for the first time.
New federal and state compliance requirements have added a second layer of risk, extending regulatory scrutiny beyond the battery itself to the controls stack. The findings come as the U.S. market posted a record 18.9 GWh of storage installations in Q2 2026.
Integration failures, not battery faults, are stalling BESS projects
When a utility-scale BESS project hits trouble at commissioning, the battery itself is rarely the problem. RES points to system integration as the primary culprit — the moment when five separate control systems must operate together under real grid conditions for the first time.
A broader equipment market means more combinations of EMS, PCS, and BMS suppliers — each with its own communication protocols, firmware versions, and update cycles.
Those five systems are the energy management system (EMS), SCADA, power plant controller (PPC), battery management system (BMS), and power conversion system (PCS). Each may perform exactly as specified in isolation. Problems emerge when they’re sourced from different vendors, developed independently, and expected to communicate in real time without prior integration testing.
“Integration risk is what customers tend to underestimate,” says Katy Perry, RES Director of Energy Storage for North America. “Each element may perform as expected on its own, but the EMS, SCADA, plant controller, BMS and PCS must all communicate with each other and with the grid in real time.”
When conflicts surface late in commissioning, the consequences are immediate: cost overruns, missed milestones, delayed revenue. These aren’t minor schedule slippages — they’re project-level failures that ripple into financing, offtake agreements, and grid interconnection timelines.
Falling hardware costs have increased, not reduced, overall project complexity
Battery hardware costs have dropped significantly over the past decade. Standardization has improved, and the vendor pool has expanded. On paper, that sounds like a recipe for simpler, cheaper projects.
It hasn’t worked out that way.
“As battery hardware has become cheaper and more standardized, customers have understandably assumed that projects overall would also become simpler,” Perry explains. “However, in practice, the opposite has happened.”
More vendors means more integration touchpoints. A broader equipment market means more combinations of EMS, PCS, and BMS suppliers — each with its own communication protocols, firmware versions, and update cycles. The battery is no longer the hard part. Procurement strategy, regulatory compliance, system integration, and long-term O&M have all become critical determinants of whether a project succeeds. Perry is direct: customers now need partners capable of managing that end-to-end complexity, not just hardware suppliers who can deliver cells on time.
U.S. federal and state rules now extend compliance requirements to the controls layer
Hardware procurement isn’t the only place where complexity has grown. The regulatory environment has added a second layer of risk — one that catches many developers off guard because it reaches well beyond the battery itself.
Foreign Entity of Concern (FEOC) rules apply not just to battery cells but to the control hardware and software that manage them. FCC rules on covered equipment and Texas’s Lone Star Infrastructure Protection Act impose further restrictions on the controls stack specifically.
Ownership structures, supply chain provenance, and remote-access pathways must all be verified for every component in the controls architecture — before contracts are signed, not at commissioning. RES identifies conducting these checks late in the process as a second major source of project delays. By the time a compliance issue surfaces at commissioning, switching vendors or restructuring supply agreements is rarely practical, and the cost penalties can be severe.
RES launches RESolve platform to consolidate BESS controls under a single architecture
RES developed RESolve to address both failure modes directly. The platform integrates the EMS, PPC, SCADA, and Electronic Security Perimeter (ESP) into a single architecture, combining those control functions with RES’s engineering expertise and grid modeling capabilities.
Because RES doesn’t manufacture batteries or inverters, RESolve is vendor-agnostic — equipment selection stays with the customer. What changes is accountability. One partner manages the full controls scope, from design through commissioning and into long-term operations, and that responsibility doesn’t end at go-live. RES structures long-term service agreements that keep the company accountable for the controls stack as grid codes, compliance requirements, and market rules evolve over the asset’s life.
RES claims the integrated approach can reduce project CAPEX, lower interconnection risk, and keep commissioning on schedule by using the control system itself to catch issues early rather than discovering them through failed vendor handoffs.
What the U.S. storage market looks like heading into 2031
The scale of what’s at stake makes these integration challenges worth solving urgently. The U.S. installed a record 18.9 GWh of energy storage in Q2 2026, with projects increasingly shifting toward longer-duration systems. Wood Mackenzie and the American Clean Power Association forecast cumulative U.S. storage capacity reaching 207 GW and 715 GWh by 2031.
Globally, storage capacity is projected to grow sixfold between 2025 and 2030, at a 42% compound annual growth rate, with China and the U.S. leading deployment. RES draws on more than a decade of operational experience across 26 projects and 13 battery and inverter suppliers worldwide. Perry frames that track record not as a credential but as a practical advantage: having seen how storage systems actually behave across different grids and regulatory environments informs how integration problems get caught before they become commissioning failures.
Why BESS commissioning risk is a controls problem
The central finding from RES is straightforward: the most common failure point in utility-scale battery storage projects isn’t the battery — it’s the controls architecture around it. Five systems from multiple vendors must integrate seamlessly, and when they don’t, projects stall.
Falling hardware costs have expanded the vendor landscape without simplifying integration. New federal and state compliance rules have extended regulatory scrutiny to the software and hardware that control the battery, not just the cells themselves. Both risks are manageable, but only if addressed early — in design and procurement, not at commissioning.
RESolve represents RES Group‘s response: a unified controls platform designed to consolidate integration risk under a single accountable partner, while leaving equipment choices open. As the U.S. market pushes toward 207 GW of installed storage by 2031, the ability to commission projects on time and in compliance may matter as much as the cost of the battery itself.
Kelly is an experienced writer with 15 years of experience exploring the big stories that shape our world, from tech breakthroughs and space exploration to climate, energy, and the fascinating quirks of science. She has a talent for turning complex ideas into sharp, memorable insights that stay with readers long after they’ve finished reading.
