@Phillip Syrios I don't have any experience with this, but this is an interesting topic. It made me do some research, which is always good. I think the general consensus on-line is having the option is a good idea.
First, I applaud renters and owners alike that want to pursue energy saving strategies. An engaged tenant would likely to stay longer as they see the landlord as in their court, helping reduce their energy bills.
My concern would be that if it's a hot day and the tenant is not cool enough, are they going to think the air conditioner is not working satisfactorily and call on a maintenance request, particularly if the air conditioner unit is a little older. Another concern is that you have given away control to the utility company, even though they may allow a certain number of "overrides" per year.
There is no substitute for good continuous insulation, energy efficient windows and a high SEER rating on mechanical equipment, but this may a step in the right direction. I wonder what else landlords could do beyond this device to create a win/win. Something as basic as regularly scheduled filter replacement, programmable thermostats, solar window film, or even something more significant like incorporating solar panels. It's a hot topic with millennials and others. It could be a way to attract tenants a differentiate your units from other by marketing the energy efficiency strategies of the home. New build statistics show people will pay more for this type of home. I'd assume you could also justify a higher rent depending on the level of improvements. Food for thought.