Quite a bit (can't find a reliable number, but looks like 300-1000kg and yes, I realize that's a wide range)
The fuel economy is actually quite reasonable unloaded - I'm getting 11L/100km vs 13 on my 370z.
The point I'm trying to make though is that it's probably not worth it to look at saving cents/kw when you're likely to come out ahead either way.
And yes, maybe more to the point of the original article - yes, if you have no car and you're only concerned with the cheapest to operate vehicle I'm confident something like a Prius driven gingerly and only filled up while gas is historically low (over a week window or whatever) you could beat an EV. On the other hand, that doesn't describe most people with cars already so for most people even living in an apartment they'd likely save money.
F150s aren’t known for having the best mileage