Sounds like a great idea for a contrib module to provide something like this. That module could also encapsulate the logic necessary for estimating energy use, as well as reports and UI to display that information where it is most useful/relevant.
Here are some relevant discussions:
It’s an interesting idea to consider time tracking and equipment resource use together. I think in practice the UI requirements may end up being different, but perhaps some of the logic underneath is similar enough to be shared… 