Doesn't seem like a big deal, as long as it's voluntary/in the job description. The better question is how they integrate it into the company (paid time?), and whether they benefit or lose by scaring off the fat employees. "Bob, your TPS reports are great, but you're just not keeping up with the group on the bikes... I'm afraid we're going to have to let you go?"
You aren't going to save a lot on electricity, because it's just not physically possible; ever pedal one of those demonstrator bikes at a science center? It's not easy to extract even 60W from a bike, and energy costs pennies by the 1,000W/h. More importantly... the safest/most comfortable workout is had with magnetic resistance (the bike acts as a generator, but the generator sinks to a dummy load, and the magnetic drag is adjusted to vary the resistance to the user, not to try to keep a constant current to a laptop)... If the particular device they're considering provides an equivalent level of comfort, and just extracts whatever energy would otherwise be lost as 'waste' from the activity, then sure, make it a voluntary convenience/incentive to plug the laptop in and be that little bit eco-friendly, but otherwise, the company is losing the money they would've saved on obesity claims treating sprains and heart attacks.
...
I think the biggest problem would be dumb managers who don't realize how inconsequential the electricity is compared to the overall well-being of their employees. Next up is the fact that I don't see it integrating into
American work weeks, especially in the tech sector, where projects are expected to hit that 'crunch time' with all hands on deck except as necessary for sleep and essential biological processes.
The bike tech is a good novelty, and a little bit useful; the sociological question of mandating exercise as part of a 'desk job' is a tougher nut to crack. (Before you
add the manager hounding you to top up your cellphone on the bike so you can save the company $0.0001...)
