SolarEdge develops 800 VDC power for AI data centres
Packing more AI computing into a server rack also means finding room for the equipment that powers it. Delivering more electricity at lower voltages requires higher currents and bulkier conductors, leaving data centre designers with a growing physical challenge between the grid connection and the processors.
SolarEdge is addressing that problem with an architecture designed to distribute electricity at 800 volts direct current, or 800 VDC. Its solid-state transformer (SST) conversion stage is operating under load in the laboratory, and the company reports conversion efficiency above 99% for its transformer cell.
The company brings experience from solar energy to this task, developing power electronics that manage how electricity from panels is harvested and converted for use. Its distinctive approach combines panel-level power optimisers, which manage individual panels’ output, with an inverter that converts DC electricity into alternating current (AC). Its move into AI infrastructure applies that experience in controlling and protecting DC power to a new set of demands.
Why AI data centres are moving towards 800 VDC
“AI is changing both the amount of power a rack needs and how quickly that demand changes,” says Igor Morozov, Vice President of Data Center Power Solutions at SolarEdge.
Racks are moving from tens of kilowatts towards megawatt scale, he explains, while large groups of graphics processing units, or GPUs, can raise or lower their consumption together. The supply system therefore has to accommodate both concentrated demand and rapid changes in electrical load.
Raising the distribution voltage addresses the capacity problem by reducing the current needed to deliver a given amount of power. In a simplified comparison between two DC supplies, delivering one megawatt at 400 volts requires 2,500 amps; at 800 volts, it requires 1,250 amps. Halving the current eases conductor requirements and helps reduce the space devoted to power delivery.
Reducing current addresses the size of the conductors, while simplifying the route through the facility tackles another source of inefficiency: each conversion between AC and DC loses energy as heat. SolarEdge’s architecture reduces the number of these conversions.
How solid-state transformers supply 800 VDC power
In the conventional supply chain Morozov describes, medium-voltage AC from the utility first passes through a transformer to become low-voltage AC. It then travels through distribution equipment and typically a double-conversion uninterruptible power supply, or UPS, which converts AC to DC and back again. At the rack, power supplies convert AC into DC once more, followed by further conversion to the low voltages the processors require.
SolarEdge’s proposed system instead connects a solid-state transformer directly to the medium-voltage supply. This technology combines semiconductor switching with a transformer operating above mains frequency to change voltage and provide electrical isolation between input and output. It delivers an 800 VDC bus: the shared electrical connection from which compatible racks receive power through individually monitored and protected feeds.
Connecting a DC UPS to that bus provides backup without converting the supply back to AC. Coordinated storage and controls also help manage the rapid demand changes caused by groups of GPUs altering their consumption together, while conversion inside each rack supplies the lower voltages needed by the electronics.
“We remove intermediate stages while designing conversion, storage and protection to work together,” Morozov says.
SolarEdge reports transformer cell efficiency above 99%
The efficiency of the transformer itself also matters, because it determines how much energy is lost during the conversion from medium-voltage AC to DC. Its building block is a transformer cell, which SolarEdge displayed alongside a model of its containerised architecture at NVIDIA’s AI Factory MGX Ecosystem Showcase during October’s Open Compute Project Global Summit in San Jose.
Laboratory measurements of that cell provide the company’s reported efficiency figure.
“Our SST cell has demonstrated medium-voltage-to-DC conversion efficiency above 99% in our laboratory,” Morozov says.
The measurement applies to the cell, while savings across an installation also depend on the intermediate equipment removed and the resulting reduction in heat losses. Space and cost benefits will vary with the facility’s design, redundancy requirements and the system used for comparison.
Protecting 800 VDC data centre power systems
The distribution system connecting that transformer to the racks must also protect people and equipment against electrical faults. If damaged insulation allows a DC conductor to touch an earthed enclosure, for example, the appropriate response depends on where the fault occurs and whether people could be exposed.
To account for these different circumstances, SolarEdge developed a protection framework ,while working with NVIDIA, that distinguishes restricted facility areas from the rack interface, where personnel work. Within a restricted area, a suitable grounding and monitoring arrangement can allow a first insulation fault to be located while operation continues, subject to the design’s safety conditions. At the rack interface, the approach calls for immediate interruption.
To detect and respond to such faults, SolarEdge’s candidate implementation combines insulation monitoring, measurements on individual branches and solid-state interruption. The aim is to isolate the affected circuit and limit disruption to healthy circuits wherever the fault conditions permit.
Interrupting DC faults presents a particular challenge because the current has no natural zero crossing to help extinguish an arc, as AC does. SolarEdge is working with Infineon on solid-state circuit breakers using silicon carbide semiconductor technology, designed to interrupt faults within a few microseconds without mechanical contacts.
That switching speed forms part of a wider protective system. Morozov stresses that personnel protection depends on the complete installation, including grounding, stored energy, detection and fault-clearing behaviour. The framework sets out the required functions without prescribing particular equipment, allowing different vendors to implement them.
Bringing solar experience into AI infrastructure
Several of these functions draw on SolarEdge’s solar business, where high-voltage DC conversion, arc detection, insulation monitoring, disconnection and storage integration are established engineering tasks. Monitoring large fleets of connected equipment has also helped the company understand how components and protection algorithms behave over time.
Adapting that experience to continuously operating data centres involves a different electrical environment: fault detection must work against a different electrical-noise background, and protection must prevent a local problem from unnecessarily interrupting healthy loads.
Coordinating protection across connected equipment also requires suppliers to work together. “This is an industry-wide shift that no single company will deliver alone,” Morozov says. SolarEdge’s work with NVIDIA and Infineon reflects that shared effort, while its roadmap aligns with the wider rollout of compatible 800 VDC racks: a working laboratory system is targeted by the end of 2026, followed by pilot installations in 2027 and volume deployment in 2028. For operators, the potential payoff is less equipment between the grid and the rack, lower conversion losses and more space available for computing.
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