In order to conserve electricity (and therefore operating costs), as many items as possible should be powered down when not in use. Office lights should have timers/motion sensors installed that turn them off after a certain period of inactivity. Printers can be powered down at the end of the day (or when they are not in use - sometimes I use my printer only a few times a week). Scanners should remain powered off and should only be turned on when they are needed. Computer updates can be scheduled to push through on a particular night each week, allowing computers to be powered down the majority of non-working hours.