Hello all, I'm new to the forums and this seemed like the perfect place to discuss an issue that has been bugging me. I know MW refers to power (the rate of energy production basically in millions of Joules per second) and MWh refers to energy (essentially the total amout (in millions of Joules) of energy produced in an hour). But from time to time I've seen "MW/hr". Sometimes I think it must be a mistake and whoever wrote it must have meant "MWh", however on other forums (e.g. Yahoo! Answers) I remember seeing that MW/hr would indicate the rate of change of power but there didn't seem to be agreement on whether it was actually a real unit. So is this really a valid unit?