Proxima Fusion plans a EUR 140 million plant to make the tape its own magnets need

The factory's first customer is Proxima. Francesco Sciortino, the company's co-founder and CEO, said "Alpha and Stellaris will create the demand required to build this manufacturing expertise locally" ^[17]. The press release makes the same point from the supplier's side: long-term purchase volumes will be critical to scaling production, retaining manufacturing expertise and reducing the cost per metre ^[15]. The plant's cost per metre depends on Proxima's own two machines getting built.

The EUR 140 million works out at roughly EUR 2,300 for every kilometre of tape those machines will need ^[10]. The figure is construction capex measured against captive demand. Proxima did not disclose the plant's annual output, a price per metre, or which bodies fund the public share beyond Lower Saxony, so the proposition that tape volume paces the fusion buildout cannot be tested against the published figures.

Proxima wants the total investment financed equally by private capital and public funding ^[6]. An even split of EUR 140 million puts the public half at EUR 70 million, and Lower Saxony's EUR 21 million is exactly 30 percent of that ^[5][11]. The release calls the state's share just under 30 percent of the proposed public contribution. Either the public pot is a little above EUR 70 million, or the whole investment runs past the EUR 140 million booked for the first two phases ^[11]. "We are making Lower Saxony a pioneer in European HTS manufacturing," said Olaf Lies, the state's Minister-President ^[18].

The case in the record is about where the tape is made. It becomes superconducting at relatively high temperatures and carries current with almost no resistive loss, which is what makes the compact, powerful magnets that hold a stellarator's plasma in place ^[19]. Industrial-scale production sits primarily in Asia ^[12]. Sciortino said Lower Saxony can "turn a supply-chain dependency into an enduring strategic strength for Germany and Europe" ^[26].

Make-or-buy on a critical input turns on whether your own demand fills a production line, and whether anybody other than you buys the thing. Proxima's own demand is about 60,000 kilometres of tape across two machines ^[9]. The other buyer is Veir, which is not a fusion company and uses HTS tape to raise the efficiency and power density of data centres ^[21].