If the math is right... Even if they are just break even, it is a win. It minimizes their future risk of getting burned by high energy prices which resulted in billions in losses and almost killed them a couple of years ago. They will be dabbling until they see some huge benefit. It is a lot cheaper to dabble in alternative technologies now, and help drive the technology, then it is to take billion dollar losses because FFs went up in price. UPS is also investing another 18M in solar panels for their facilities.
You can basically go right down the list of corporations who are merely trying to break even with the newer technology. It gives them a fixed cost on their balance sheet, rather then a variable cost that is a risk.
As far as vehicle to grid. BMW is testing something with their i3's in cali. i don't know if they needed to make mods to the cars or not. Bluebird school buses are incorporating it. Nissan is working on it. I am not sure it will pan out. Namely because battery prices have dropped 50% in the last two years, and I expect them to continue to drop in price. The big benefit is not having to buy batteries, but if batteries continue to drop in price it isn't nearly as big of a long term issue.
In general, the us/canada system isn't set up for compensation from storage which goes down to the regional and state level laws and regulations. It is a problem.
I thought about doing that with the VIA Silverado and the Chevy volt. The Volt doesn't have enough space, so you really just need to find a cheap one, and use the electronics. But I think it would be a lot cheaper just to find a junk lawn tractor, hook it to an induction motor, and then run the output through a rectifier to your solar system inverter. It cleans up all the messiness in the output.