LAUNCESTON, June 15 -- On five hectares of farmland outside Launceston, a computing campus is going up that will, once it is finished, draw more electricity than any other customer in Tasmania. Not a smelter. Not a mine. A building full of chips that make artificial intelligence, owned by a company headquartered in Singapore.

The company is Firmus, and it calls the project Southgate the most cost-effective and sustainable AI facility in the world, powered start to finish by Tasmania's hydro-electric grid. That is the pitch. The arithmetic underneath it is where the story gets harder. At full build the campus is designed to consume up to 400 megawatts, and the first stage alone carries an investment of about A$2.1 billion. The number of o...