Maritime Fusion, a superconducting energy and fusion technology company, closed a $4.5M seed round led by Trucks VC, with participation from Paul Graham, Aera VC, Alumni Ventures, Y Combinator, and others. The funding supports development of HTS cable and tokamak programs.
The HTS magnet lab in San Francisco has begun rapid prototyping and testing. Recent bench tests ran 5kA through the SHIELD (Superconducting High Integrity Energy Link & Distribution) cable cooled with liquid nitrogen. The SHIELD design features a compact, modular architecture capable of handling up to 8kA at 77K and higher currents under fusion-relevant conditions, offering industry-leading current densities with thermal stability and mechanical robustness. Lengthwise insulation and optimized soldering reduce AC and eddy current losses. Compared to copper, the HTS solution is smaller, lighter, and nearly lossless, requiring ~1.5W/m of cryocooling at 77K.
Parallel work focuses on Yinsen, a low-power-density HTS tokamak. Partnerships include Columbia University via a Sponsored Research Agreement and the DOE’s DIII-D National Fusion Facility for pulse scenario experiments.