fan speed may be received at controller 212 from temperature sensor 306 and or fan speed sensor 308 in another example power levels at dc power supply 302 may be determined based on signals that are carried by power sensing line 312 power needs of a power consumer may be determined block 406 in one implementation the power needs may be determined based on the amount of power that is delivered to the power consumer from rps module 204 in another implementation the power needs may be based on information that is inputted by a user a number of parallel power supplies that are needed to supply power to the power consumer may be determined block 408 the number may be determined based on the power needs of the power consumer the amount of power each parallel power supply is capable of delivering and or the received criteria rules for example if the power needs of the power consumer is 1000 watts each parallel power supply is capable of delivering 300 watts and the received criteria rules require the parallel power supplies to be capable of delivering at least 150 of power that is being consumed at the power consumer the total number of parallel power supplies that are needed may be computed as 1000 watts u00d7 150 300 watts per.