AI workloads have broken the traditional data center power stack. A single GPU rack can now draw over a megawatt, and the industry’s reference architectures are converging on 800 VDC (±400 VDC) distribution to keep pace with rack-level density. The century-old iron-core transformer, sitting at the front of that stack, has become the bottleneck — both in lead time and in the sheer amount of legacy switchgear it drags along with it.
The solid-state transformer (SST) is the technology stepping into that gap. Instead of copper windings and a steel core, an SST uses high-frequency SiC or IGBT-based power semiconductors and software-defined control to convert voltage, route power from multiple sources, and respond to load swings in milliseconds. For hyperscale and colocation operators, that means a smaller footprint, native DC output, and — in theory — one box replacing a room full of transformers, switchgear, UPS units, and PDUs.
This roundup looks at the ten companies shaping the data center SST supply chain in 2026: integrators building complete SST systems, the semiconductor and DC protection suppliers whose components make those systems certifiable, venture-backed pure-plays building SST boxes from the ground up, and industrial incumbents bringing decades of grid experience to the table.
Quick Comparison: SST Ecosystem Players at a Glance
| Company | Category | Core Offering | Primary Data Center Focus |
|---|---|---|---|
| HIITIO | SST integrator + DC protection & power semiconductor components | Modular SST (1.2–5 MW), HVDC contactors, semiconductor fuses, SiC/IGBT power modules | Full SST solution for data centers, plus certified protection components for other integrators |
| Heron Power | SST integrator (startup) | Heron Link — integrated SST + battery buffer | 34.5kV AC to 800V DC, replacing MV transformer, UPS, and PDU |
| DG Matrix | SST integrator (startup) | Interport — multi-port SST platform | Multi-source power routing for AI and BESS-backed facilities |
| Amperesand | SST integrator (startup) | Medium Voltage SST (MV-SST) | Fortune 100 hyperscale deployments beginning 2026 |
| Enphase Energy | SST integrator (public) | IQ Solid-State Transformer | Distributed 342-module supercluster for 800V DC racks |
| Hitachi Energy | Industrial incumbent | TXpert-enabled transformers, SST R&D | Grid-side transformers plus SST research for data center segments |
| ABB | Industrial incumbent | Grid-connected MV power electronics R&D | SST development out of Zurich and Mannheim engineering centers |
| Eaton | Industrial incumbent (via acquisition) | Resilient Power Systems SST technology | MV SST demonstrations for data center pilot programs |
| SolarEdge Technologies | SST integrator (public) | Modular 2–5 MW SST building block | AI data center power blocks, developed with Infineon |
| Delta Electronics | Industrial incumbent | SST-compatible power architectures | Leveraging existing UPS and PDU business across Asia-Pacific |
1. HIITIO — Modular SST Systems and the DC Protection Components Behind Them
HIITIO occupies a somewhat unusual position on this list: it is both an SST integrator and a supplier of the DC protection components that other integrators depend on. On the systems side, the HIITIO Solid-State Transformer is a modular platform built around power electronic conversion and high-frequency magnetic isolation, purpose-built for data centers, EV charging and battery-swapping stations, AC/DC hybrid distribution networks, and wind-solar-storage integration.
For data center applications specifically, the platform steps 10 kV/13.8 kV/35 kV medium-voltage AC directly down to DC output — 240 V, 400 V, 750 V, or 800 V DC — in a single pre-integrated cabinet, eliminating the oil-cooled transformer, phase-shifting transformer, and separately commissioned power quality equipment that a conventional power chain requires. See HIITIO’s Data Center Power Solution for the broader system context this SST sits inside.
Key reference specifications for the data center configuration:
- Rated power: 2.4 MW per cabinet, expandable to 3 MW, with a broader 1.2–5 MW range across the product line
- Peak efficiency: >97.5%, versus roughly 85.8% for UPS-based systems — HIITIO cites a savings estimate of 28.11 million kWh over 10 years for a 10 MW data center switching from UPS to SST
- Input THDi: ≤2% at 50–100% load, with power factor ≥0.99
- Redundancy: 25% module-level hot standby, with automatic bypass of any failed module and no system downtime
- Zero no-load loss, compared to the roughly 1% continuous no-load loss typical of line-frequency transformers
- Commissioning time: approximately 20 days for the pre-fabricated cabinet configuration
Underneath that system-level offering sits the same protection layer HIITIO has long supplied to third-party SST integrators, EV, and ESS manufacturers: HCF series HVDC contactors (20A–1,200A, up to 2,500 VDC, ceramic vacuum sealing, non-polarized arc extinguishing), semiconductor fuses (aR/gR type, sub-10-millisecond clearing, low I²t let-through), and SiC, IGBT, and SiC/Si hybrid power modules — all UL, CE, CB, CCC, and TÜV certified. HIITIO’s own technical breakdown of why HVDC contactor selection can make or break an SST design and its guide to semiconductor fuse solutions for data centers cover this layer in more depth, as does its broader look at where value and risk sit across the SST supply chain.
GET A CUSTOM SST QUOTE FOR YOUR DATA CENTER PROJECT
That dual position matters for procurement teams: HIITIO can be sourced as a complete SST system for a data center power project, or as the coordinated fuse-and-contactor protection layer inside another integrator’s SST design — a flexibility not every name on this list offers. Background on how SST architecture differs from conventional transformers is covered in HIITIO’s primer, What Is a Solid-State Transformer?
2. Heron Power — Heron Link Integrated SST + Battery Buffer
Founded by former Tesla energy executive Drew Baglino, Heron Power has become one of the most closely watched SST startups after closing a $140 million Series B in February 2026, co-led by Andreessen Horowitz’s American Dynamism Fund and Breakthrough Energy Ventures, bringing its cumulative funding to roughly $178 million.
The company’s Heron Link product converts 34.5 kV AC directly to 800 VDC output at over 98.5% conversion efficiency, integrating an MV disconnect switch and a 40-channel DC distribution panel with per-channel overcurrent protection into a single 4.2 MW unit. Per Heron’s own technical documentation, a single unit is designed to replace the MV transformer, UPS, switchgear, and PDU altogether, removing the need for a dedicated electrical room in the process. Heron is building a 40-gigawatt manufacturing facility in the United States, with pilot production targeted for early 2027.
3. DG Matrix — Interport Multi-Port SST Platform
DG Matrix’s differentiator is port density: its Interport platform is built to maximize the number of DC and AC ports on a single unit, letting one SST replace multiple pieces of conventional switchgear and power conversion equipment. The company closed a $60 million Series A in February 2026 led by Engine Ventures, bringing total funding past $100 million, and partnered with Infineon Technologies in March 2026 for SiC component supply. DG Matrix targets both hyperscale AI data center operators and EV charging network operators, and has partnered with BESS company Ampace to build UL-certified, grid-active battery systems around its SST architecture.
4. Amperesand — Medium Voltage SST for Hyperscale Campuses
Amperesand raised an $80 million Series A in November 2025, co-led by Walden Catalyst Ventures and Temasek, and is targeting 30 megawatts of commercial MV-SST deployments to Fortune 100 hyperscale customers in 2026. The company positions its Medium Voltage Solid-State Transformer as a single-unit replacement for the multitude of discrete electrical systems typically required in an AI data center power chain, with first commercial units expected to ship in 2026.
5. Enphase Energy — IQ Solid-State Transformer
Best known for residential solar microinverters, Enphase is moving into AI data center power with its IQ Solid-State Transformer, a distributed 1.25 MW “supercluster” built from 342 hot-swappable power modules rather than a small number of large power blocks. The architecture uses gallium nitride switching, a proprietary high-frequency transformer, and Enphase’s custom Kestrel control ASIC, and is rated for 98.5% peak efficiency. Enphase disclosed the program alongside its Q1 2026 earnings and has indicated a roadmap toward customer pilots in 2027 and volume shipments in 2028.
6. Hitachi Energy — TXpert Transformers and Grid-Side SST R&D
Hitachi Energy brings decades of high-voltage transformer manufacturing to the data center segment, including a stated $1 billion US investment plan that includes a large power transformer factory in South Boston, Virginia. On the SST side specifically, industry analysis identifies Hitachi Energy as one of the two leading players in the broader solid-state transformer market, with research programs coordinated out of Zurich and Tokyo. Its data center product line today centers on liquid-filled and dry-type transformers with TXpert digital monitoring, alongside longer-term SST research aimed at MV distribution architectures.
7. ABB — Grid-Connected Medium-Voltage Power Electronics
ABB’s SST development is coordinated through its grid-connected medium-voltage power electronics program, with engineering activity based in Zurich and Mannheim. Alongside Hitachi Energy (a former ABB business), ABB is frequently cited as one of the two market leaders in the broader SST space, leveraging certified utility interconnection expertise that is directly transferable to data center applications — a credentialing advantage that matters to operator procurement teams who prioritize reliability track record over spec sheets alone.
8. Eaton — Resilient Power Systems SST Technology
Eaton entered the data center SST conversation through its acquisition of Austin-based Resilient Power Systems, bringing medium-voltage SST technology into one of the world’s largest electrical equipment manufacturers. Eaton has also been reported to be pursuing SST pilot programs in Southeast Asia, including a containerized MV-SST demonstration planned in partnership with a Singapore university testbed. The acquisition route reflects a broader pattern in this market: established players augmenting organic R&D with startup technology rather than building SST capability from scratch.
9. SolarEdge Technologies — Modular SST Building Blocks
SolarEdge, like Enphase, is extending its solar inverter and power electronics heritage into AI data center infrastructure. The company entered the SST market through a November 2025 collaboration with Infineon, targeting a modular 2–5 MW SST building block designed specifically for AI data center deployments. As with Enphase, SolarEdge’s approach leans on its existing manufacturing scale and semiconductor supply relationships rather than a from-scratch hardware program.
10. Delta Electronics — SST-Compatible Power Architectures
Delta Electronics is approaching the SST opportunity from its existing position in data center UPS and power distribution equipment, particularly across the Asia-Pacific region. Rather than a standalone SST product line, Delta is developing SST-compatible power architectures out of its Taipei engineering centers, aiming to integrate solid-state conversion technology into its established UPS and PDU business as the market matures.
Why the Protection Layer Gets Overlooked
Most coverage of the SST market focuses on the semiconductor race and the integrator platforms — Heron Link, Interport, IQ SST — because that’s where the headline efficiency numbers and funding rounds sit. What gets less attention is the protection and isolation layer that has to surround the power electronics before any of these systems can be safely commissioned, insured, and operated at scale.
A few practical realities drive this:
- Pre-charge sequencing is non-negotiable. Before an SST’s DC bus capacitors can be energized, a pre-charge contactor and current-limiting path are required to prevent damaging inrush current — this has to be engineered in at the design stage, not added afterward.
- Fuse-contactor coordination determines fault survivability. A fuse’s peak let-through current and I²t value must stay within the contactor’s withstand rating, or contact welding becomes a real risk during a fault event.
- Certification breadth shapes deployment speed. UL, CE, CB, and CCC coverage across component suppliers determines how many regional markets an SST design can enter without a redesign — a factor procurement teams weigh as heavily as raw efficiency specs.
This is the layer where HIITIO’s component business sits relative to the nine integrators above — supplying the DC contactors, semiconductor fuses, and power modules that determine whether an SST design passes certification and survives its first fault in the field. HIITIO is somewhat unusual in also building a complete SST product on top of that same protection layer, giving procurement teams the option to source a full data center SST system and its underlying protection components from a single, vertically integrated supplier.
Market Context: Why This List Will Keep Changing
One market research estimate puts the solid-state transformer for data centers segment at roughly $40.3 million in 2025, projected to reach $572.4 million by 2034 — a reflection of just how early and fast-moving this space still is. Combined venture funding across DG Matrix, Amperesand, and Enphase’s SST program has topped $240 million in under twelve months, and Eaton’s acquisition of Resilient Power Systems signals that established electrical equipment manufacturers are actively acquiring SST capability rather than waiting to build it internally. Expect this list of ten to shift as first-generation commercial deployments generate field performance data over 2027–2028.
Frequently Asked Questions
Is a solid-state transformer the same thing as a conventional transformer with electronics bolted on? No. A conventional transformer converts voltage passively through magnetic induction between copper windings. An SST replaces that entirely with high-frequency power semiconductor switching stages — typically operating between 1 kHz and 100 kHz — combined with software-defined control. This is what allows an SST to also provide native DC ports, bidirectional power flow, and millisecond-level load response, none of which a passive magnetic transformer can do on its own.
Why is 800V DC specifically becoming the reference architecture for AI data centers? As GPU rack power density climbs past a megawatt, the current required to deliver that power at lower voltages becomes impractical — cabling, connectors, and busbars all scale with current, not power. Moving to 800 VDC (often implemented as ±400 VDC) cuts the current for a given power level roughly in half compared to legacy 400V architectures, which is why NVIDIA’s reference designs and most SST vendors on this list are converging on it.
Do data centers need to choose between an SST integrator and individual protection components? Not exactly — these are typically different layers of the same system. SST integrators like the startups covered above build and sell the conversion box itself. Component suppliers such as HIITIO supply the HVDC contactors, semiconductor fuses, and power modules that go inside that box, or that protect the DC buses connecting it to battery storage and IT load. Most SST deployments require sourcing decisions at both layers.
How mature is this technology for production data center deployment? As of mid-2026, most of the integrator-side products on this list are in pilot or early commercial stages, with several vendors targeting volume shipments between 2027 and 2028. The underlying protection and semiconductor component layer — contactors, fuses, SiC/IGBT modules — is comparatively mature, since these components have already been qualified across EV, ESS, and industrial DC applications for years.
HIITIO: Your Solid-State Transformer and DC Protection Partner for Data Center Projects
If your team is evaluating a solid-state transformer, 800V HVDC architecture, or next-generation data center power system, HIITIO can help at both layers of the stack. Source a complete HIITIO Solid-State Transformer — 1.2MW to 5MW, >97.5% peak efficiency, medium-voltage AC direct to DC — or specify our HVDC contactors, semiconductor fuses, and SiC/IGBT power modules inside your own SST design. With 20+ years of manufacturing experience, UL/CE/CB/CCC/TÜV certification across our product lines, and in-house testing capability, HIITIO helps data center operators, SST integrators, and EPC contractors source coordinated, certifiable power systems instead of stitching together suppliers part by part. Contact HIITIO’s engineering team to discuss your SST or DC protection requirements.
