Who makes HVDC for AI data centers

High-voltage direct current is how bulk power moves a long way, or between grids that are not synchronised with each other. Over distance, DC lines lose less than AC and need less right-of-way for the same transfer; the cost is a converter station at each end, which is a substantial power-electronics installation in its own right. That fixed cost is why HVDC is used for long links and interconnectors rather than for ordinary transmission. It matters to this catalog because the places with abundant generation and the places where AI campuses are being built are increasingly not the same places, and because underground and subsea cable is often the only route a new line can take through populated areas. HVDC is the technology for both cases. The supply picture is a bottleneck worth understanding. Converter stations come from a very short list of manufacturers, and high-voltage cable from a similarly short list of factories with the specialised production and testing capacity required. Both have order books filled years out by European offshore wind and interconnector programmes, so a new project joins a queue rather than placing an order. What to look for is factory capacity and its commitments rather than announced projects, and whether a supplier makes converters, cable, or both — they are separate constraints and a project needs both.