A system for placing and maintaining a computer in a standby mode during power failure, utilizing one of: a powered device controller exhibiting a maintain power signature functionality and arranged to receive power over communication cabling; and a MEMS flywheel energy system to provide a standby power. The standby power is less than the power required for full operation. In one embodiment the system additionally exhibits: a mains power failure sensor; a volatile memory arranged to be powered from the source of standby power in the event of a failure of mains power; and a processor operative responsive to the mains power failure sensor to store status information on the volatile memory and reduce power demand of the processor and associated devices to no more than that available from the source of standby power.