Method of operation of a vehicle electrical system with electrically assisted turbocompressor

The internal combustion engine (4) of the motor vehicle is coupled to an electrically boosted turbo-compressor (2) and the method involves operating the electrically boosted turbo-compressor as a generator from time to time to supply electrical energy into the on-board electrical system (10). The motor vehicle contains an electrical generator (3) and the generator and turbo-compressor can be operated to reduce the total power loss of the motor vehicle. AN Independent claim is also included for the following: (a) an electrically boosted turbo-compressor (b) and a motor vehicle with an electrically boosted turbo-compressor.