Datacentre dive: ‘We’re at Chinese levels’ at TeraWulf 750MW AI factory

Electricity the draw

This 1,800-acre plot on the isolated shores of Lake Ontario, formerly home to the Somerset coal-fired power station, is undergoing a seismic mutation – from defunct monument of the fossil-fuel era into a 1.2 million square foot AI factory. 

The key asset here is not the land, but the raw copper and steel of the existing grid tie-in in the form of two independent 345kV import connections capable of pulling power from two separate utility providers. Where the old coal plant once generated 675MW and employed 270 people, TeraWulf’s development is scaling towards a final 750MW allocation. 

The site also features an under-construction 125MW solar array, which, said a TeraWulf executive, exports electricity to the grid but which will likely come straight back for use in the datacentre.

From bitcoin to AI factory

The financial and physical scale of the transition demonstrates the step change we’re seeing as we move into the AI factory age. During the site’s initial tenure under Beowulf (from which TeraWulf was spawned), it was used for bitcoin mining. Design centred on low-grade, air-cooled halls and the cost was approximately $500,000 per megawatt. 

Processing occurred in long, narrow halls where simple ventilation moved air across the servers and out the other side, with a required 1Gbit wide-area network (WAN) connection. 

The Nvidia-dictated GPU roadmap changed the scale completely. With a capital expenditure of $10m per megawatt, the buildings have become squarer to compress the physical distance between processing clusters. The site – comprising five datacentre buildings – will eventually run around 100,000 GPUs and require terabit-scale WAN pipelines routed directly into the primary network arteries of Buffalo and New York City.

Direct-to-chip liquid cooling

That kind of GPU density creates unprecedented cooling and resource challenges. Direct-to-chip liquid cooling (DLC) is standard across all data halls to manage the immense thermal output of the processing cores.

Meanwhile, the initial closed-loop fill requires roughly 350,000 gallons of water per data hall – totalling nearly 1.4 million gallons across the current multi-building construction block, which equates roughly to the annual consumption of 10 American households. This will be drawn from the local municipal grid’s potable water supply, but will require minimal top-up through their lifetime. 

Cooling of the warmed water will eventually require 175 Evapco condensing units – each the size of an oversized double-decker bus – to continuously vent heat into the air.

To achieve this scale, the pace of work is occurring at “Chinese levels” of construction intensity and rapidity, according to one on-site TeraWulf executive. It’s a purposeful and well-organised 24-hour industrial grind involving 1,600 workers on two shifts that drive a staggered, relentless three-to-four-week lag between successive halls to allow ongoing customer access to the colo facility.