The article says, right at the start,

> Anexia was founded in 2006, is based in Austria, and provides cloud services from over 100 locations around the world by placing equipment in third party datacenters.

From the company's homepage:

> The founder and CEO of Anexia [...] recently acquired a small hydropower plant in Kammern in the Liesingtal region of Styria for a “significant seven-figure sum” – i.e. several million euros. The power plant on the River Liesing generates 600 KW of electricity, enough to cover a third of the electricity consumption of Anexia’s Vienna data center

so this seems to be a significant operation.