It's basically time-shifting. Either you can turn this geothermal energy into electricity and have the consumer charge their car at home over a long period of time (hours) or you can turn it into a full tank of gasoline over a long period of time (hours), ship it to the consumer to fill their tank in a short period of time (minutes).

Either way, it takes a long time. The difference is the impact to the consumer of converting it to something useful for them (gas), or having them convert it to something useful (a charged battery). The consumer doesn't notice the gasoline taking a long time, to them it takes minutes.