Now THAT'S a plan, but having multiple time devices around the world can't possibly end badly, especially when you consider bad guys might have the tech, too.
I'd wonder if all that extra energy from nowhere would end up heating the planet as well, but then I realized that if such became a problem, then you could just time-cheat the waste heat away as well.
Short answer: Yes it would.
Long answer: Would it be enough to make a difference? Depends on the scale. More research needed, consult Randall Monroe for possible answers.
And what's the big FUCK YOU to Blankenship, Justice, and Murray, might I ask? True, the diamonds are virtually worthless now due to oversupply, but those guys are still evil enough to find a new way to screw the people over.