The Boeing Company is investigating a High Speed Civil Transport (HSCT) aircraft which will transport 300 passengers at speeds up to Mach 2.4. Such a high speed, high altitude aircraft presents unique environmental and safety requirements. The aircraft electrical power system configuration must provide the required redundancy and reliability necessary to supply power for fly-by-wire flight control buses as well as other aircraft loads. Emergency power backup must be considered for various power failure conditions. This paper presents some of the issues affecting the electrical power system design, and some of the possible solutions which will be considered.