SemiAnalysis published a report on 7 November on its visit to Inner Mongolia, which it calls China’s fastest-growing region for AI data centres. The first 120-megawatt phase of the Galaxy campus in the city of Ulanqab was completed in under a year at a fifth of US costs, the firm said. The basis for the comparison is in the paid section of the report.

The megawatt figures refer to IT capacity, the power allocated to servers. The first phase was completed in August. All four phases of the campus are being built for two unnamed internet giants, and the full 800-megawatt campus is due for completion by the end of 2027. SemiAnalysis compares Galaxy with OpenAI’s Stargate campus in Abilene, Texas, and estimates the Abilene campus’s IT capacity at about 820 megawatts.

A local news story cited in the report said nearly 30,000 construction workers were working on 22 data centre projects in the surrounding Chahar High-tech Zone. Data centres face more opposition than ever in Texas but none in Inner Mongolia, SemiAnalysis said. The visit was part of fieldwork for the China data centre model the firm sells.

Own wind power and batteries

The campus is owned by Envision, which builds renewable energy systems and has installed more than 100 gigawatts of wind turbines worldwide. Envision is building dedicated wind farms for the data centre and a dedicated transmission line from them that bypasses the public grid.

The wind farms have a combined capacity of 420 megawatts, about 1.75 times the 240-megawatt load of the first two phases. A four-hour battery storage system shifts power from windy hours to calm ones. Envision aims to cover more than 60 per cent of these phases’ electricity consumption with its own wind power. The battery is of little help if calm weather lasts for days, the report said.

SemiAnalysis said data centre rents in China have halved in five years to about $40 per kilowatt per month excluding power. Capital cost is below $3 million per megawatt, and electricity in Inner Mongolia costs about $0.055 per kilowatt-hour. The report said the projects’ returns are low, and that for Envision the data centres create new demand for its own electricity and equipment. It is too early to say whether self-sufficiency taken this far will become a significant competitive advantage, SemiAnalysis said.

Direct current straight to server racks

In one hall, solid-state transformers (SSTs) convert 10-kilovolt alternating current (AC) from the grid directly into 800-volt direct current (DC) for the server racks. This removes the need for low-voltage transformers, uninterruptible power supplies (UPS) and rectifiers.

Nvidia is promoting 800-volt DC for its next-generation high-density server racks, but in the US the approach is still only at the planning stage, SemiAnalysis said. The Galaxy trial is just 5 megawatts. A larger version is planned for the next phase.

Chinese data centres have used DC for almost two decades, initially at 240 volts. Roughly a quarter of data centres built in China over the past decade run on DC, the report said. In the US, about 97 per cent of data centres use AC UPS.

Liquid- and air-cooled servers share the same water loop, and the campus has no central chiller plant. SemiAnalysis said the approach has been widely used in northern China for years, whereas most US data centres have a chiller plant for air-cooled equipment.