Trigger warning: what follows is annoyingly pedantic, especially since it was probably a typo, but..
Megawatts or watts by themselves already have the time unit in them, so saying 1MW/hr is like saying more joules of energy *per second* every hour. Technically that means that every hour it somehow has another megawatt of power (just wait, by the end of the day we should be at 24MW! Nobody would actually think that’s what it is meant to mean though… so not a big deal.