Consider a situation where the students have to be away from the?
The utility bills will be low, but they will not be zero. Depending on the climate, either the air conditioning or the heat may have to be run at least minimally in the appropriate seasons to prevent damage to the building. Additionally, custodial and maintenance staff will likely be working at least part of the time for cleaning and repair work. Although they might not turn on the AC or the heat for these workers, they will have to turn on the lights.