The 140-year-old iron-core transformer is a core technology supporting power grids and AI companies' power infrastructure, but it is being criticised for showing its limits as data-centre power demand surges. Against that backdrop, interest in solid state transformer, or SST, technology is growing.

TechCrunch reported on March 10 that related startups have raised $280 million in recent months. Hyperscale Power presented a more advanced solution based on SST and stressed that "there is no product as small as our system." The company recently raised a 5 million euro seed round and began developing a prototype.

The SST market has grown rapidly in recent years. Competitors include Ampersand, backed by Temasek's early-stage fund; DG Matrix, backed by industrial conglomerate ABB; and Heron Power, founded by former Tesla executive Drew Baglino and backed by Andreessen Horowitz. PitchBook said the companies have raised more than $330 million in total.

Hyperscale Power may look like a latecomer, but co-founders Daniel Rottmund (다니엘 로트문트) and Sami Pettersson (사미 페테르손) have studied the technology in the field for a long time. Hyperscale Power plans to reduce size further by developing a transformer that operates at higher frequencies than competitors.

Rottmund said, "Existing transformers are more than twice the size of a server rack," adding, "Without SST, data-centre expansion will be delayed."