Solid-State Transformers

SiC power electronics · 800 V DC · makers

One solid-state transformer can replace the transformer, UPS and rectifiers between the grid and an AI rack. It needs no electrical steel and no transformer factory slot.

Feeding an 800 V DC AI rack today takes a chain of equipment: medium-voltage switchgear, an iron-core transformer, low-voltage switchgear, a UPS and a rack rectifier. A solid-state transformer converts medium-voltage AC to 800 V DC in one box. Heron Power says it removes about 70% of the gear. SST startups raised more than $280 million in about a year; Heron Power plans a 40 GW-a-year US factory with pilot production in early 2027. MEDIUM-VOLTAGE GRID TO 800 V DC RACK TODAY MV gearswitchgear Transformeriron core LV gear480 V AC UPSAC-DC-AC Rectifierto 800 V DC WITH A SOLID-STATE TRANSFORMER MV gearswitchgear Solid-state transformerMV AC to 800 V DC in one box; SiC switches 800 V rack ~70%less gear (Heron Power) $280M+raised by SST startups in a year 40 GW/yrHeron factory target ~98.5%claimed peak efficiency
Gear removed
~70%
Startup funding
$280M+
Heron factory
40 GW/yr
Pilot production
Early 2027
Hub
Energy

Finding

SSTs go around the transformer shortage, and AI data centers are the first big buyer

A solid-state transformer replaces the iron-core transformer with silicon carbide power electronics. It needs no grain-oriented electrical steel and no 128-week factory slot, and it can output DC directly. That fits the 800 V DC rack power NVIDIA and more than 20 partners are standardizing for AI data centers: one SST can replace the transformer, low-voltage switchgear, UPS and rectifiers between the grid and the rack.

Money and orders arrived in 2025-26. Heron Power, founded by former Tesla executive Drew Baglino, raised $140 million in February 2026 for a 40 GW-a-year US factory, with pilot production in early 2027 and customer interest above 40 GW. DG Matrix raised $60 million, backed by ABB, and says it is the only SST maker shipping a commercial product; its unit is in NVIDIA's MGX reference design. Amperesand raised $80 million and plans about 30 MW of systems in 2026. About a third of Heron's demand is data centers; the rest is solar and battery plants, where an SST can replace both inverter and transformer.

The open questions are the ones that decide grid adoption: peak efficiency around 98.5% against more than 99% for large iron-core units, decades-long field life still unproven, fault-current behavior, and UL and utility standards that are only now being written. Full-scale 800 V DC deployment is tied to NVIDIA's Kyber racks in 2027, and analysts expect SSTs to reach the end state around 2029.

SST vs iron core

What changes

Solid-state vs conventional transformer
FactorIron-core transformerSolid-state transformer
CoreIron core of grain-oriented electrical steel, 50/60 HzSmall high-frequency magnetics; SiC or GaN switches
SizeLarge, heavy, oil-filledCompact; Heron claims ~70% less space
OutputAC only, fixed ratioAC or DC, programmable, multiple ports
Power flowPassiveBidirectional, controlled in milliseconds
Efficiency99%+ for large units~98.5% claimed peak
Life40+ years, well knownUnproven beyond pilot fleets
Supply chainGOES, copper, factory slots; 2-3 year leadSiC devices, capacitors, magnetics; electronics-style factories

Who builds them

SST makers

Solid-state transformer makers: product, status
CompanyBaseProductStatus
Heron PowerUSHeron Link: MV AC to 800 V DC; solar, BESS, data centers$140M Series B (Feb 2026); pilot production early 2027; 40 GW/yr factory planned
DG MatrixUSMulti-port SST (Interport); data centers, microgrids$60M Series A; ABB-backed; Infineon SiC supply; in NVIDIA MGX
AmperesandSingapore / USMV SST for data centers$80M (Nov 2025); ~30 MW planned for 2026
Delta ElectronicsTaiwanMV AC to 800 V DC SST shown with 800 V DC racksNVIDIA 800 V DC partner
Eaton (Resilient Power Systems)USSST for EV charging and grid edgeBought Resilient Power Systems in 2025; SST line inside Eaton
Hitachi Energy, Siemens Energy, GE Vernova, ABBIncumbentsSST programs alongside iron-core linesListed as NVIDIA power-system providers

Where they go

Five applications

SST applications
ApplicationWhat the SST does
AI data centersMV AC to 800 V DC at row or building; removes UPS and rectifier stages
Solar plantsReplaces inverter plus step-up transformer
Battery storageBidirectional MV interface; grid-forming control
Truck and fleet depotsMV feed to a DC bus for megawatt chargers and batteries
Grid edgeVoltage regulation and DER hosting at the feeder

Sources

Sources and scope

Scope
Solid-state transformers for data centers, generation, storage, charging and the grid edge
Sources
TechCrunch and company announcements (Heron Power, DG Matrix, Amperesand); Power Electronics News on NVIDIA GTC 2026; Data Center Richness; SemiAnalysis via market reporting
Updated
October 2026