The power supply for new generation of the long life spacecraft is one of the complicated problem staying in front of designers within practically all the space vehicle life phases. Up to day the most widespread solution consists of the own on board power supply system for each spacecraft including main (usually solar arrays or radioisotope thermal electric units) and redundant (usually chemical accumulating batteries) power sources. The technical and cost efficiency aspects of an advanced scheme of spacecraft power supply by the directional power beams from board of several Space Power Plants is analyzed. Practically all possible spacecraft types are included into the study: systems of communication satellites in the LEO and GEO, navigation and remote sensing satellites operated in the orbits with altitudes to 25000 km, surveillance and technology space platforms into LEO, as well as orbital maneuvering vehicle equipped with electrical propulsion to transport payloads from LEO into operational orbit. The preliminary evaluation of PowerSat's and servicing spacecraft systems orbital configuration is presented. Side by side with some characteristics of the power generation units (on base of solar arrays, solar thermal dynamics facilities, nuclear power plants) the brief discussion of electric thrusters and power transmission system is provided. The perspectives and ways of the further studies for all of main PowerSat's subsystems are nominated.