sentences:  To provide a black start, some power stations have small diesel generators, normally called the "black start diesel generator" (BSDG), which can be used to start larger generators (of several megawatts capacity), which in turn can be used to start the main power station generators.Generating plants using steam turbines require station service power of up to 10% of their capacity for boiler feedwater pumps, boiler forced-draft combustion air blowers, and for fuel preparation.It is uneconomical to provide such a large standby capacity at each station, so black-start power must be provided over designated tie lines from another station.