The Open-Source Solid-State Transformer Control Software Question: Why Vendors Won’t Open Source and Why Customers Want Them To
- SST control software is the single most valuable IP in the device — converter modulation, protection, grid-forming behavior
- Vendor case against open source: differentiation erosion + legal liability from customer modifications
- Customer case for open source: avoid vendor-lock-in risk especially under acquisition/financial-crisis scenarios
- Middle ground: tiered open-source for safety-critical + comms layers, proprietary higher-value algorithms
- Linux Foundation Energy effort exists; Heron Power and DG Matrix are most likely open-source-first candidates
The control software running on the digital-signal-processor (DSP) board inside every commercial solid-state transformer (SST) is the single most valuable piece of intellectual property in the device. The control software implements the converter switching modulation, the protective coordination, the fault detection and ride-through, the grid-forming or grid-following behavior, the optional virtual-synchronous-machine emulation, and the telemetry generation. The control software is also the single most opaque part of any commercial SST product, and the absence of open-source SST control software has emerged as a notable customer concern through 2025 and 2026.
The vendor case against open-sourcing SST control software is straightforward. The control software is the differentiation between competing SST products that use the same underlying silicon-carbide MOSFETs, the same medium-frequency transformer, and the same DC-link capacitor families. Open-sourcing the control software would erode the differentiation and would expose vendor-specific control techniques to competitive imitation. Open-source release also creates legal exposure — a customer who modifies the control software and produces a safety incident could attempt to assign liability to the vendor.
The customer case for open-source SST control software is also straightforward. Utility customers and hyperscale data-center operators face vendor-lock-in risk when their installed-base SST units depend on proprietary control software that only the original vendor can patch, update, or extend. The risk compounds if the original vendor exits the market, is acquired, or experiences a financial crisis. Customers want either source-code escrow arrangements that activate under defined vendor-failure scenarios, or full open-source release of the control software with continuing vendor support for a baseline product configuration.
The middle-ground compromise that several SST manufacturers have proposed is a tiered approach: open-source release of the safety-critical layers and the standardized communication interfaces, with proprietary protection on the higher-value control algorithms and optimization layers. The Linux Foundation Energy effort to standardize distributed-energy-resource control software is the most visible community-effort organization in this space, although the Linux Foundation Energy work has not yet specifically addressed SST control.
The strategic question is whether any SST manufacturer breaks ranks and adopts an open-source-first product strategy. Heron Power, with its Drew Baglino-led Tesla heritage of relatively open product architectures, is the most likely candidate among the startups. DG Matrix, with its multi-port architecture that benefits from broad ecosystem integration, is another candidate. Whether one or more SST manufacturers adopt open-source-first positioning by 2028 will materially affect the competitive structure of the industry.
Why It Matters
For utility buyers, the DSP control software is the most valuable and most opaque part of any SST, governing switching, protection, ride-through, and grid-forming behavior, and vendors will not open-source it while customers increasingly want to. That tension over control-software access is a real procurement risk: a utility locked out of the code is dependent on the vendor for the life of a grid asset, which is a different ownership model than iron-core hardware ever imposed.
Critical Perspective
Editorial correction: This post is part of MGRID’s Solid-State Transformer industry coverage. As of May 2026, that body of work systematically framed manufacturer announcements, funding rounds, and laboratory demonstrations as commercial deployments. The reality is that field-deployed commercial-class SST in revenue service globally is measured in single digits, and almost every product cited in this series is at “announced” or “funded” stage, not “operational.” Readers should treat the specific claims in this post against the standards documented in our SST Industry Reality Check (the per-claim audit table maps marketing language to verifiable deployment status). The corrective article is the canonical reference for SST industry reality; this post remains published with its original framing so the editorial drift is traceable.
Related Coverage
Linux Foundation Energy effort exists; Heron Power and DG Matrix are most likely open-source-first candidates
