A black start is the process of restoring a power station to operation without relying on the external electric power transmission network.

Normally, the electric power used within the plant is provided from the station's own generators. If all of the plant’s main generators are shut down, station service power is provided by drawing power from the grid through the plant’s transmission line. However, during a wide-area outage, off-site power supply from the grid will not be available. In the absence of grid power, a so-called black start needs to be performed to bootstrap the power grid into operation.

To provide a black start, some power stations have small diesel generators 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. Often hydroelectric power plants are designated as the black-start sources to restore network interconnections. A hydroelectric station needs very little initial power to start (just enough to open the intake gates and the excitation of the generator field coils), and can put a large block of power on line very quickly to allow start-up of fossil-fueled or nuclear stations. Certain types of combustion turbine can be configured for black start, providing another option in places without suitable hydroelectric plants.

Dante Terrell Smith (born December 11, 1973) is an American actor and MC, known by the stage names Mos Def ( /ˌmoʊsˈdɛf/) and Yasiin Bey. He started his hip hop career in a group called Urban Thermo Dynamics, after which he appeared on albums by Da Bush Babees and De La Soul. With Talib Kweli, he formed the duo Black Star, which released the album Black Star in 1998. He was a major force in late 1990s underground hip hop while with Rawkus Records. As a solo artist he has released the albums Black on Both Sides in 1999, The New Danger in 2004, True Magic in 2006, and The Ecstatic in 2009.

Although he was initially recognized for his musical output, since the early 2000s, Mos Def's screen work has established him as one of only a handful of rappers who has garnered critical acclaim for his acting work. He is well known for his portrayal of Brother Sam in the American drama series Dexter. Mos Def has also been active in several social and political causes.

He was born Dante Terrell Smith in Brooklyn, New York City, the son of Sheron Smith and Abdul Rahman. He was raised by his mother in Brooklyn; his father lived in New Jersey. While his father was initially a member of the Nation of Islam and later an active member in the community of Imam Warith Deen Mohammed, who merged into mainstream Islam from the Nation, Mos Def was not exposed to Islam until the age of 13. At 19, he took his shahada, the Muslim declaration of faith. He is friends with Ali Shaheed Muhammad and Q-Tip of A Tribe Called Quest.

Talib Kweli Greene (October 3, 1975), better known as Talib Kweli, is an American rapper. Kweli hails from Brooklyn, New York. His first name in Arabic means "student" or "seeker" (طالب); his middle name in Swahili means "true". Kweli first gained recognition through Black Star, a collaboration with fellow MC Mos Def.

Born in Brooklyn, New York, Kweli grew up in a highly educated household in Park Slope. His mother, Brenda Greene, is an English professor at Medgar Evers College of the City University of New York and his father an administrator at Adelphi University. His younger brother, Jamal Greene, is a professor of Constitutional Law at Columbia Law School, and former clerk to Justice John Paul Stevens on the Supreme Court. As a youth, he was drawn to Afrocentric rappers, such as De La Soul and other members of the Native Tongues Posse whom he had met in high school. Talib Kweli was a student at Cheshire Academy, a boarding school in Connecticut. He was also a student at Brooklyn Technical High School, before being academically dismissed. He later studied experimental theater at New York University.