Study finds significant savings from direct current power for AI workloads

A new study from Enteligent found that shifting from traditional alternating current (AC) power to 800V direct current (800VDC) can dramatically reduce cost, energy waste, and infrastructure complexity in high-density AI data centers. But Enteligent is a developer of direct current (DC) power infrastructure for high-density loads, so it has a vested interest in such findings. But does that diminish the results? CEO Sean Burke says facts are facts. “We believe that DC is more efficient,” he said. “There are higher voltage levels in DC than AC infrastructure. It’s just a fact that we can run at higher volts, DC is fewer wires, and with the higher voltage it is beneficial to what we’re doing. From the standpoint of the facts related to AC and DC efficiencies and cost savings, we believe it is undebatable.” Many would say the alternating current and direct current wars between Nikola Tesla and Thomas Edison were settled more than a century ago, but Burke says the technology has improved and change the shape of the landscape for direct current. “AC won out because the technology wasn’t ready for DC,” he said. “The main thing [at the time] was about how do you transport long distances? The technology to do that with AC was available through basically inexpensive transformers. It was not there for DC, where now where we have solid state converters to be able to take DC power to high voltages and down to low voltages.” Within the confines of a data center’s walls, DC’s efficiencies become apparent. With DC, there are two power cables. With AC, there are 4 wires. So there is considerable wiring savings in an all-DC facility. Also, with higher voltage comes a lower current and current is what generates heat. So data centers that can run on 800VDC can run cooler. The result is a 50% to 80% reduction in copper usage, due to fewer conductors and less parallel cabling, and an 8% to 12% reduction in annual energy-related OpEx through lower conversion and distribution losses. By reducing conductor count, cabling, and redundant power components, 800VDC enables meaningful savings at both build-out and operational stages. AI-first facilities can see a $4 million to $8 million in CapEx savings per 10 MW build by reducing upstream AC. For a one-gigawatt data center, you’re saving a couple million pounds of copper wire, he said. Burke says an all-DC data center is best done with a whole new facility rather than retrofitting old facilities. “[DC] is going to be in a lot of greenfield data centers that are going to be built, and data centers that are going to go to higher compute power are also going to DC,” he said. He did recommend all-DC retrofits for existing data centers that are going to employ high power computing with GPUs. Enteligent’s unnamed and as yet unreleased product is a converter that takes 800 volts and partitions it to 50 volts for the computing servers. The company will provide a new power supply, power shelf that converts 800 volts DC to 50 volts DC much more efficiently than any current power supplies. Burke said the company is doing NDA level testing and pilot programs now with its product, but it will be making a formal announcement within the next few weeks. There are a number of players in the DC arena focusing on different parts of the power supply market including Vertiv, Rutherford, Siemens, Eaton and many more.