A hydrogen gas dryer or system for drying or removing water from hydrogen gas for use in hydrogen-cooled generators includes a drying tower or column comprising a housing, a heater, a desiccant, and a controller. The system is configurable and operable for regeneration of the saturated column, with activation of the heater to cause water retained in the saturated desiccant to turn into steam such as steam and exit on its own via the vent. A supply of generally dry hydrogen is used to purge the remaining vaporized water from the isolated substantially dry regenerated desiccant.