Monolith From PYR recent news release...
PyroGenesis’ technology boasts a theoretical
electricity cost 3 times lower than that of water electrolysis to produce the same amount of hydrogen making it one of the most energy-efficient technologies to produce ZCE hydrogen.
Monolith which has already built a pilot plant claims electricy cost 7X lower then water electrolysis. They also use plasma for methane pyrolysis.
https://monolith-corp.com/process-comparison